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Dissertations / Theses on the topic 'Rubber carbon black dispersion'
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1
Choi, Jaesun. "Ultrasonically Aided Extrusion of Rubber Nanocomposites and Rubber Blends." University of Akron / OhioLINK, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=akron1362747207.
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Gunewardena, J. Anoma G. S. G. "Development and evaluation of dispersing agents for carbon black filled natural rubber compounds." Thesis, Loughborough University, 1999. https://dspace.lboro.ac.uk/2134/32245.
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Various additions are used in rubber compounds to accelerate mixing with particulate fillers and to improve behaviour in subsequent processing operations. Cationic surfactants of general structure [RNH2(CH2)3NH3]2+ 2[R'COO] can be used in rubber processing as multifunctional additives (MFA) which act as processing aids, accelerators and mould releasing agents. However, with all these beneficial properties an adverse effect of decreased scorch time was observed when N–tallow–1,3 diaminopropane dioleate (EN444) was used in the filled natural rubber compound.
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Ren, Xianjie ren. "Use Of Fly Ash As Eco-Friendly Filler In Synthetic Rubber For Tire Applications." University of Akron / OhioLINK, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=akron1463148731.
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Parris, Donald R. "Electrical characterization of carbon black filled rubber." Thesis, Virginia Polytechnic Institute and State University, 1986. http://hdl.handle.net/10919/91055.
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DC resistance and AC conductance and capacitance have been measured under various conditions in an effort to electrically characterize and make electrical-mechanical correlations for 15 carbon black filled rubber samples.
Resistance, conductance and capacitance have been monitored as functions of uniaxial compressive stress, time, temperature, and mechanical and thermal history. Capacitance and conductance have also been monitored as functions of frequency under various degrees of compressive loading and before and after specific heat treatments.
A direct relationship has been found between sample • conductance and capacitance under any thermal and/or mechanical condition. This is in agreement with previous theories of conduction network formation and percolation. Various conduction mechanisms have been enumerated and an equivalent circuit of a network of lumped R-C "microelements'' has been qualitatively described. Stress, relaxation, frequency, and temperature dependences of the macroscopic parameters measured ( conductivity and capacitance) are discussed in terms of this model.M.S.
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Jobando, Vincent Okello. "Positron annihilation spectroscopy study of rubber-carbon black composites." Fort Worth, Tex. : Texas Christian University, 2006. http://etd.tcu.edu/etdfiles/available/etd-12052006-093021/unrestricted/Jobando.pdf.
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Lucchese, Laurence. "High temperature stabilisation of carbon black filled natural rubber." Thesis, Manchester Metropolitan University, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.310622.
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Chen, Chin Jung. "Electrical and mechanical stress responses for carbon black loaded rubber." Thesis, Virginia Polytechnic Institute and State University, 1987. http://hdl.handle.net/10919/101177.
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The major objective of this study was to determine the relations between certain electrical parameters (resistance, capacitance) and mechanical parameters (stress, strain) for carbon black loaded rubber. Resistance and capacitance were measured under constant strain and constant stress conditions in an effort to determine these relations for rubber filled with 30 to 70 parts carbon black per hundred parts rubber.
Seven materials for making electrical contact were investigated. Silver paint was found to result in low contact resistance, to be reliable, and fairly inexpensive.
Electrical parameters (resistance, capacitance) and mechanical parameters (stress, strain) were found to exhibit similar trends as functions of carbon black content. This is in agreement with previous theories of the conduction network and electron percolation. Resistance and stress relaxation equations were quantitatively determined. These follow a power law time dependence, with relaxation rates depending mainly on carbon black content and temperature.M.S.
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Akrach, Majda. "Carbon black dispersion using polymeric dispersants prepared via raft polymerisation." Thesis, University of Warwick, 2012. http://wrap.warwick.ac.uk/103089/.
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The aim of this thesis is the investigation of the use of a RAFT agent developed by the company Lubrizol, BMDPT (Butyl-2-methyl-2-[(dodecylsulfanylthiocarbonyl) sulfanyl] propionate) produced in tonnes scale to make amphiphilic block copolymers in ester solvent (butyl acetate and methoxypropyl acetate). For this purpose, a broad range of monomers including acrylate, methacrylate and styrenic containing tertiary amine were polymerised and used as pigment dispersants. As the starting point, the reactivity of n-butyl acrylate (n-BA) and di(methyl)aminopropyl acrylate (DMAEA) monomer followed by the synthesis of acrylate diblock copolymers in acetate solvents (butyl acetate and methoxypropyl acetate) are investigated. The second chapter is focused on the methacrylate polymerisation which is a large body of work of this thesis. The poor reactivity of the trithiocarbonate RAFT agent towards methacrylate monomer was already published few times. Consequently, the kinetic studies of butyl methacrylate (BMA) and di(methyl)amino ethyl methacrylate (DMAEMA) was investigated in batch mode. Subsequently, a new synthetic route is explored to reach a well-controlled diblock copolymers. In the third chapter, a novel class of amphiphilic diblock copolymer containing acrylate and a mixture of styrene and maleic anhydride is explored. Then, the functionalisation of polymer backbone is carried out by using an amine in order to insert an anchoring group for pigment affinity. Finally, the efficiency of all the diblock copolymers on carbon black pigment dispersion is reported. A combination of different techniques such as dynamic light scattering (DLS), transmission electronic microscopy (TEM) and thermogravimetric analysis (TGA) are used to investigate the interaction between the polymer and the pigment.
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Bethea, Robert A. "The Effects of Carbon Black Reinforcement Systems on Crosslinked Shape Memory Elastomers." University of Akron / OhioLINK, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=akron1418301296.
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Wang, Qinwei. "Effect of Tensile Rate and Carbon Black on the Fracture of Natural Rubber and Styrene-Butadiene Rubber." University of Akron / OhioLINK, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=akron1365778539.
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Park, Hanki. "Comparison of Carbon Black and Silica on Crack Growth Resistance." University of Akron / OhioLINK, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=akron1415367098.
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Wen, Ming. "The effect of carbon black crystallinity on dispersion in SBR matrix." University of Akron / OhioLINK, 2021. http://rave.ohiolink.edu/etdc/view?acc_num=akron1619022632906256.
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Hussain, Syeda Aquila. "EFFECT OF CARBON BLACK FILLERS ON HIGH STRAIN RATE PROPERTIES OF NATURAL RUBBER." University of Akron / OhioLINK, 2005. http://rave.ohiolink.edu/etdc/view?acc_num=akron1133450613.
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Xue, Tianxiang. "Tearing of Black-Filled (N660) Synthetic Polyisoprene Rubber Vulcanizates at Various Temperatures." University of Akron / OhioLINK, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=akron1366125713.
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Rwei, Syang-Peng. "Observation and analysis of carbon black agglomerates dispersion in simple shear flows." Case Western Reserve University School of Graduate Studies / OhioLINK, 1991. http://rave.ohiolink.edu/etdc/view?acc_num=case1055357306.
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Hwang, Yawlin. "Dynamic electromechanical measurements of carbon black loaded SBR." Thesis, Virginia Tech, 1988. http://hdl.handle.net/10919/43862.
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The major objectives of this study were to examine electrical and electromechanical properties of SBR filled with carbon black in the 0-70 phr range. The experiments were divided into four parts: dielectric measurement, loss modulus and phase angle measurements, temperature rise measurement during stress cycling, and dynamic conductivity measurement.
It is established that there are three distinct conduction regimes existing at carbon black loadings below, at, and above the percolation threshold. Characteristics of dielectric dispersion depend strongly on carbon black loading and frequency. Dielectric and AC conductivity measurements are shown to provide a nondestructive method to explore the carbon black network inside the rubber.
Both loss modulus and phase angle are related to hysteresis properties, and to temperature rise due to compressive cycling. Measurements of these parameters will be discussed in detail, as functions of carbon black loading, stress and strain amplitudes, and oscillation frequency. These and other results can be understood in terms of the mechanics of the carbon black network. The variation of conductivity with strain amplitude is related directly to the interplay between the "persistent" and "transient" fractions of carbon black network. It is shown that, owing to its experimental accuracy and great sensitivity to carbon black network changes, the dynamic conductivity measurement is preferable to traditional modulus measurements for determining certain dynamic properties of carbon black filled rubbers.Master of Science
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Ahmed, Ismail Mostafa. "Modified lignin as replacement of carbon black in elastomers- For the development of sustainable tyre technology : The substitution of carbon black with modified lignin- Green tyre technology." Thesis, Karlstads universitet, Avdelningen för kemiteknik, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:kau:diva-78707.
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Due to its large flexibility, low-price, large availability, and properties lignin is seen as an important compound with a wide range of applications. The increasing demand of fossil-based rubber materials is causing a serious threat to the environment and it is contributing to plastic- and marine pollution, ozone depletion and carbon dioxide emission (CO2) [1,2]. Numerous toxicological researches highlight that Carbon black may act as a universal carrier of wide variety of chemicals of varying toxicity to the human body [3,4]. Consequently, researcher endeavours in finding sustainable and eco-friendlier alternatives. The aim of this thesis was to further investigate the possibilities of replacing carbon black with modified lignin in rubber elastomeric materials- for the development of sustainable tyre technology. The research questions for this thesis were divided in four parts: How does lignin (unmodified and modified) structure affect the mechanical properties of the rubber compound? How does lignin affect the cross-link and vulcanisation of the rubber compound? How does lignin affect the dispersion of the rubber compound? Which modification of lignin is more compatible with the rubber compound? Lignin is the second most abundant biopolymer on earth (after cellulose) and is mainly extracted from black liquor, which is obtained as a by-product from the pulp- and paper. In this study, pure lignin was obtained from Lignoboost process (Lignocity) and underwent an esterification process of aldehydes (1. Protonic, 2. Butyric, 3. Isobutyric 4. Methacrylic and 5. Crotonic). LignoCity 2.0 is a project focusing on the development of sustainable products and processes connected to lignin. The structure of the modified lignin was characterized using a FTIR-spectra. Furthermore, seven different rubber compounds were produced at Anva Poly Tech, which is a company that manufactures rubber materials in Sunne, Sweden. The mechanical testing involved: Tensile strength, IRHD, Hardness, Rebound Resilience and Rheometer curve. It was observable that the addition of lignin in rubber compounds did not significantly improve the mechanical properties compared to conventional carbon black. However, the rheometer curves of the lignin samples clearly indicate an increase in scorch time and that lignin takes part in the vulcanization process, thus the delay in crosslinking phase. In addition, it was visible that the fully replacement of carbon black with lignin (unmodified and modified) increased the elongation at break. Furthermore, the FTIR spectra indicated a complete and successful modification of lignin. In addition, compared to unmodified lignin, it was visible that the modified lignin significantly improved the mechanical properties. Therefore, it was possible to conclude that the configuration and double bonds of the aldehydes had an impact on the vulcanization process. Butyric and isobutyric lignin were the better choices compared to the other lignin samples.De rådande miljöproblemen som: plast- och gummiutsläpp i havet, växthusgasutsläppet och den ekologiska utarmningen i kombination med den ökande efterfrågan av fossilbaserade material har lett till en ökad satsning på att hitta mer hållbara och miljövänligare alternativ [1, 2]. Kimrök i gummimaterial utgör en del hälsorisker och samtidigt har negativ påverkan på miljön. Flertals studier visar att långtidsexponering av kimrök kan ge allvarliga lungproblem och även cancer [3,4]. På grund av dess stora tillgänglighet, låga kostnad och unika egenskaper anses lignin vara en möjlig och intressant framtidskandidat för ersättande av fossila produkter. Syftet med denna studie var att undersöka möjligheterna om att ersätta kimrök med modifierad lignin i gummimaterial för utvecklandet av ’grönare däckteknologi’. Frågeställningarna i detta arbete var uppställda i fyra i olika delar: Hur påverkar tillsättningen av lignin (omodifierad och modifierad) gummiblandningens mekaniska egenskaper? Hur påverkar tillsättningen av lignin tvärbindningarna och vulkningen i gummiblandningen? Hur påverkas tillsättningen av lignin gummiblandningars dispersion? Vilken modifikation av lignin är mest kompatibel med gummimaterialet? Lignin är en organisk biopolymer som är den näst mest (efter cellulosa) förekommande biomassan i naturen och produceras som en biprodukt från pappers- och massa industrin. Ren lignin erhålls genom extraktion från svartlut med diverse isolations metoder. I detta arbete erhölls lignin genom Lignoboost processen från Lignocity. Lignocity 2.0 är ett projekt som syftar till att utveckla, kommersiella och effektivisera hållbara processer och produkter med fokus på lignin. I detta arbete modifierades ligninet genom en s.k. esterfierings process av fem olika aldehyder 1.Propionic, 2. Butyric, 3. Isobutyric, 4. Methacrylic och 5. Crotonic som sedan undersöktes i en FTIR-spektra. Sju olika gummiblandningar skapades (inklusive ett gummi som endast innehöll kimrök och ett gummi som ej innehöll kimrök eller lignin). Gummiblandningarnas mekaniska egenskaper undersöktes på följande sätt: Dragstyrka, IRHD (Hårdhet), Hårdhet, studselasticiteten och reometrisk karaktärisering De ligninbaserade gummiblandningarna gav ingen signifikant förbättring i de mekaniska egenskaperna. Dock visade den reometriska kurvan att tillsättning av lignin gav en ökning i bränntid samt att ligninet gav en förskjutning i tvärbindningsfasen. Vidare gav den reometriska kurvan en indikation på att ligninet deltog i vulkaniseringsprocessen. Isobutyric lignin hade den högsta bränntiden. Det var även bevisat att tillsättningen av lignin gav en ökning i töjning. Modifieringen av lignin gav en signifikant förbättring av de mekaniska egenskaperna jämfört med omodifierad lignin. FTIR-spektrumet av ligninproven indikerade på en lyckad modifiering och koppling av aldehydgrupperna. Trots att de ligninbaserade gummiblandningarna inte förbättrade de mekaniska egenskaperna så kunde intressanta kopplingar mellan aldehydens konfigurationer, dubbelbindningar och vulkaniserings processen göras. Butyric och isobutyric visade bäst resultat jämfört de andra ligninproven.
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Hariwongsanupab, Nuttapong. "Development of green natural rubber composites : Effect of nitrile rubber, fiber surface treatment and carbon black on properties of pineapple leaf fiber reinforced natural rubber composites." Thesis, Mulhouse, 2017. http://www.theses.fr/2017MULH0399/document.
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Les effets du caoutchouc nitrile (NBR), du traitement de la surface des fibres et du noir de carbone sur les propriétés des composites à base de caoutchouc naturel renforcé par des fibres d'ananas (NR / PALF) ont été étudiés. L'incorporation de NBR et le traitement de surface de la fibre ont été utilisés pour améliorer les propriétés mécaniques des composites à faible déformation, alors que le noir de carbone a été utilisé pour améliorer ces propriétés à forte déformation. La teneur en fibres a été fixée à 10 phr. Les matériaux composites ont été préparés à l'aide d'un mélangeur à cylindres et ont été réticulés sous presse permettant ainsi le maintien de l'orientation des fibres. Ces composites ont été caractérisés à l’aide du rhéomètre à matrice mobile (MDR), par analyse thermique mécanique dynamique (DMTA) et par tests de traction. La morphologie après fracture cryogénique a été observée à l'aide de la microscopie électronique à balayage (MEB). L'effet du NBR dont la teneur varie de 0 à 20 phr par rapport à la teneur totale en caoutchouc, a été également étudié. Le NBR est utilisé afin d’encapsuler totalement les fibres d’ananas (PALF) ; ceci conduisant à un meilleur transfert de contraintes entre la matrice et les fibres. La méthode de mélange a également été étudiée. Plusieurs types de silanes tels que le propylsilane, l'allylsilane et le silane-69 ont été utilisés pour traiter les fibres pré-nettoyées à l’aide d’un traitement alcalin. Les fibres silanisées ont été caractérisées par spectroscopie infrarouge à transformée de Fourier (FTIR), par spectroscopie de photoélectrons aux rayons X (XPS) et par MEB. Le traitement de la fibre par le silane-69 a permis d’augmenter fortement le module du matériau composite à faible déformation. Ce traitement a été plus efficace que l'incorporation de NBR dans les composites NR / PALF. Ceci peut s’expliquer par une possible réticulation chimique entre le caoutchouc et la fibre traitée au silane-69 plutôt qu’une simple interaction physique du NR, du NBR et de la fibre. Cependant, le renforcement par fibre réduit la déformation à la rupture. Par conséquent, du noir de carbone a également été incorporé dans les composites NR/NBR/PALF et NR/ PALF traitée, afin d’améliorer leurs propriétés ultimes. En incorporant du noir de carbone à un taux de 30 phr dans les deux composites, les propriétés mécaniques des composites ont été améliorées et peuvent être contrôlées à la fois à des déformations faibles et hautesThe effects of nitrile rubber (NBR), fiber surface treatment and carbon black on properties of pineapple leaf fiber-reinforced natural rubber composites (NR/PALF) were studied. The incorporation of NBR and surface treatment of fiber were used to improve the mechanical properties of composites at low deformation, whereas carbon black was used to improve these properties at high deformation. The fiber content was fixed at 10 phr. The composites were prepared using two-roll mill and were cured using compression moulding with keeping the fiber orientation. These composites were characterized using moving die rheometer (MDR), dynamic mechanical thermal analysis (DMTA) and tensile testing. The morphology after cryogenic fracture was observed using scanning electron microscopy (SEM). The effect of NBR from 0 to 20 phr of total rubber content was investigated. NBR is proposed to encase PALF leading to higher stress transfer between matrix and PALF. The method of mixing was also studied. For the fiber surface treatment, propylsilane, allylsilane and silane-69 were treated on the alkali-treated fiber. Treated fibers were characterized using Fourier-Transform infrared spectroscopy (FTIR), x-ray photoelectron spectroscopy (XPS) and SEM. Silane-69 treatment of fiber increased the modulus at low deformation more than the incorporation of NBR of NR/PALF composites due to the chemical crosslinking between rubber and fiber from silane-69 treatment rather than the physical interaction of NR, NBR and fiber. However, reinforcement by fiber reduced the deformation at break. Hence, carbon black was also incorporated into NR/NBR/PALF and NR/surface-treated PALF composites to improve the ultimate properties. By incorporation of carbon black 30 phr in both composites, the mechanical properties of composites were improved and can be controlled at both low and high deformations
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Sun, Ximei. "THE DEVULCANIZATION OF UNFILLED AND CARBON BLACK FILLED ISOPRENE RUBBER VULCANIZATES BY HIGH POWER ULTRASOUND." University of Akron / OhioLINK, 2007. http://rave.ohiolink.edu/etdc/view?acc_num=akron1176388229.
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Rao, Tingling. "Effect of Crosslink Density and N660 Carbon Black on Tearing Behaviors of Natural Rubber Vulcanizates." University of Akron / OhioLINK, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=akron1347122467.
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Sun, Yu. "Tearing of Carbon Black-filled and Gum Natural Rubber Vulcanizates Cured with Dicumyl Peroxide (DCP)." University of Akron / OhioLINK, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=akron1380201814.
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Li, Zhenpeng. "Effect of Carbon Black on the Tearing of Dicumyl Peroxide (DCP)-cured Natural Rubber Vulcanizates." University of Akron / OhioLINK, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=akron1398358292.
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Sandell, Viktor. "Extraction of Material Parameters for Static and Dynamic Modeling of Carbon Black Filled Natural Rubbers." Thesis, Luleå tekniska universitet, Materialvetenskap, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-65583.
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Volvo Car Corporation (Volvo Cars) develops powertrain mounting systems that uses components made up largely of filled rubber materials. The development of such components is today relying on external suppliers to design components based on requirements set by Volvo. To reduce costs and lead-time in the development process the possibility of in-house design of such components at Volvo Cars is being investigated. For this to be possible, knowledge must be built concerning modelling the mechanical properties of rubber materials. As part of this a parameter extraction method for modelling of filled rubber materials intended for finite element use has been developed in this project. Both a simple static model fitting procedure and a more complex dynamic model fitting procedure are detailed. Mechanical testing of four filled natural rubber materials with varying hardnesswas carried out at the facilities of Volvo Cars and recommendations have been made regarding the limits of the equipment and the specific test body geometry used. It was found that the lower limit for dynamic testing in regards to displacement amplitude is 0.02 mm. The highest frequency recommended is dependent on the material hardness but a higher limit of 200 Hz is recommended for the softest material investigated. The upper limit was found to be necessary due to inertia effects in the material. The models used to describe the static behaviour were hyperelastic phenomenological models independent on the second invariant such as the Yeoh and the linear neo-Hookean models. The dynamic model used the overlay method to capture therate and amplitude dependent properties of filled rubber. A generalized viscoelastic-elastoplastic rheological model using Maxwell and friction elements in parallel with alinear elastic element was presented and used. These were limited to having maximumfive of each element and no attempts at minimizing this number was made in this work.The dynamic model was fitted to experimental data using a minimization procedure focusing on dynamic modulus and damping at a range of frequencies and strain amplitudes.The proposed fitting procedure is a three segment loop in which FE simulationsof the experimental data is used as both a correction and a validation tool.Model validation showed good correlation of the fitted model to measured databefore correction was attempted. The correction step did not improve the model qualityand the reason for this was identified as poor post-processing. The proposed method together with lessons learned during the course of the project will be of importance for the future in-house development of rubber components at Volvo Cars.
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Liang, Lan. "Recovery and evaluation of the solid products produced by thermocatalytic decomposition of tire rubber compounds." Diss., Texas A&M University, 2004. http://hdl.handle.net/1969.1/4938.
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A thermal catalytic decomposition process has been developed to recycle used tire rubber. This process enables the recovery of useful products, such as hydrocarbons and carbon blacks. During the catalytic decomposition process, the tire rubber is decomposed into smaller hydrocarbons, which are collected in the process. The solid reaction residue, which normally consists of carbon black, catalysts, other inorganic rubber compound components, and organic carbonaceous deposits, was subjected to a series of treatments with the intention to recover the valuable carbon black and catalyst. The process economics depend strongly on the commercial value of the recovered carbon black and the ability to recover and recycle the catalysts used in the process. Some of the important properties of the recovered carbon black product have been characterized and compared with that of commercial-grade carbon blacks. The composition of the recovered carbon black was analyzed by TGA and EDX, the structure and morphology were studied through transmission electron microscopy (TEM), and the specific surface area was measured by BET nitrogen adsorption. The recovered products possess qualities at least comparable to (or even better than) that of the commercial-grade carbon black N660. Methods for increasing the market value of this recovered carbon black product are discussed. Anhydrous aluminum chloride (AlCl3) was used as the primary catalyst in the process. A catalyst recovery method based on the AlCl3 sublimation and recondensation was studied and found to be non-feasible. It is believed that the catalyst forms an organometallic complex with the decomposed hydrocarbons, such that it becomes chemically bonded to the residue material and hence not removable by evaporation. A scheme for the further study of the catalyst recovery is suggested.
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Fan, Yiran. "The development of novel sustainable carbonaceous materials as substitutes for carbon black in rubber-based products." Thesis, Imperial College London, 2017. http://hdl.handle.net/10044/1/54642.
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Carbon black is a commodity material which is used mostly as a reinforcing filler in rubber and plastic production. Its manufacture is not only energy-consuming, contributes significantly to global CO2 emissions, but uses non-renewable feedstock making it unsustainable. Given the increasing pressure against the continued use of non-renewable sources of feedstock, there is an exciting opportunity to develop alternative materials to act as rubber fillers for environmental and economic reasons. This research has focused on the development of novel carbonaceous rubber fillers produced through the pyrolysis of coconut shell and raw sewage sludge. The basic properties of feedstock were evaluated to assess the efficacy of final filler performance; a Response Surface Methodology was applied to model the relationship between pyrolysis conditions and the key physical and chemical properties of the char filler and to optimise the pyrolysis process. Feedstock were pyrolysed using a laboratory-scale furnace using various temperatures, heating rates, holding times and atmospheres. A comparison was made between char fillers and commercial carbon blacks to establish the optimum production conditions. The selected char fillers were mixed with styrene-butadiene rubber and the rubber products were evaluated for their technological performance. Therefore, a fundamental understanding of the rubber-char filler interaction and the performance of the sustainable fillers was developed. By-products (oil and gas) were also studied as a wider sustainability study embedded within the research. The coconut shell and raw sewage sludge have significant potential for use as a sustainable feedstock for carbon black replacement in rubber manufacture. These fillers were found to have equivalent surface area (2.9 – 318.2m2/g) to a semi-reinforcing filler and provide 52 – 59° hardness, 482 – 962% elongation at break to the rubber products. Further research has been identified to improve post-production processing and rubber formulation which would help further optimize and improve the product for in-rubber use.
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Adepetun, Adeyemi Adedayo. "Effect of Carbon Black Loading and Temperature on Cut Growth in N990-Filled Natural Rubber Vulcanizates." University of Akron / OhioLINK, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=akron1315575370.
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Lee, Michael W. "Microwave sensing of bulk electrical properties of tank track pad rubber." Thesis, Virginia Polytechnic Institute and State University, 1988. http://hdl.handle.net/10919/80089.
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A complex permittivity measurement system composed of a network analyzer and a open-ended coaxial waveguide has been used to evaluate the permittivity of rubber samples. The conductivity of rubber provides an indication of the dispersion of carbon black throughout the rubber matrix. The technique is based on the Deschamps antenna modeling theorem which relates the effective admittance of an antenna in some arbitrary medium to the effective admittance of the same antenna embedded in free space. This technique is well suited for material with loss tangents between 0.1 and 1.0. Only material within a radius on the order of the outer conductor radius of the coaxial waveguide is interrogated. Inferred permittivity measurements for rubber samples are presented. An APC-7 connector is used as the transducer which provides a means for convenient calibration because standard calibration terminations can be used. The amount of pressure from the sample applied to the waveguide affects reflection coefficient measurements, preventing consistent results.Master of Science
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Norton, Edward. "Steady State and Dynamic Oscillatory Shear Properties of Carbon Black Filled Elastomers." University of Akron / OhioLINK, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=akron1553332886931084.
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Rodrigues, David Ernest. "Structure property relationships in track pad rubber as a function of blending conditions." Thesis, Virginia Tech, 1987. http://hdl.handle.net/10919/40955.
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Tank track pads have been known to degrade rapidly under adverse conditions, especially during cross country service where the average life has been estimated to be 500 miles. Several factors have been identified as being the cause for such low service life. One of these is the 'quality of dispersion' which plays an important role in the performance of any rubber compound. In order to evaluate the effect of the quality of dispersion on the service life of rubber compounds, a controlled blending experiment was carried out with a recipe modeled on a standard track pad formula. Mechanisms of failure produced by a bad dispersion have been identified. Two interesting observations were made, one of which was the formation of voids and the other was crack propagation along flow lines which are directly relatable to processing conditions.
Master of Science
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Joshi, Tirtha Raj. "MOLECULAR MOBILITY OF UNFILLED AND CARBON BLACK FILLED ISOPRENE RUBBER STUDIED BY PROTON NMR TRANSVERSE RELAXATION AND DIFFUSION." University of Akron / OhioLINK, 2008. http://rave.ohiolink.edu/etdc/view?acc_num=akron1199906776.
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Albehaijan, Hamad A. "Approaches to Enhance Filler-Polymer Interactions and Cure Properties of Rubber Compounds." University of Akron / OhioLINK, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=akron1491515276428703.
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Österlöf, Rickard. "Modelling the viscoplastic properties of carbon black filled rubber : A finite strain material model suitable for Finite Element Analysis." Doctoral thesis, KTH, MWL Marcus Wallenberg Laboratoriet, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-184879.
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An increased environmental awareness, legal demands and the large part of total costs attributable to fuel cost are all incentives for the automotive industry to reduce fuel consumption. The optimal driveline to enable this reduction depends on the operational conditions and the available infrastructure. Moreover, special care is needed when developing the driveline isolators, since the demands on noise, vibration and harshness (NVH) are the same regardless of driveline. To this end, computer aided calculations can be used in order to evaluate a large number of configurations. However, these calculations are only, at best, as good as the material models employed. In the foreseeable future, rubber with reinforcing fillers will be used in vibration isolators in order to obtain the desired properties of these components. However, the stiffness and damping of rubber with reinforcing fillers are highly non-linear functions, and the available material models in commercial software and in the literature are often insufficient. Therefore, a finite strain viscoplastic material model is derived in the time domain and implemented as a user defined material model in Abaqus Explicit. The model captures the strain amplitude and frequency dependency of the storage and loss modulus for a carbon black filled natural rubber. The model is accurate over a wide range of shear strain amplitudes and frequencies, 0.2-50 % and 0.5-20 Hz, respectively, using only 5 material parameters. In addition, the model correctly captures the response from bimodal excitations. The implementation in Abaqus Explicit enables component characteristics to be evaluated early in the development phase, with material parameters derived from simple test specimens. The improved accuracy of simulations of these components can aid engineers develop more optimized solutions faster than with conventional methods.En ökad miljömedvetenhet, juridiska krav och den stora delen av de totala kostnaderna som kan hänföras till bränslekostnader är alla incitament för fordonsindustrin att minska bränsleförbrukningen. Den optimala drivlinan för att möjliggöra denna minskning beror på driftförhållanden och den tillgängliga infrastrukturen. Dessutom ställs höga krav på utvecklingen av drivlineisolatorer, eftersom kraven på buller och vibrationer (NVH) är desamma oavsett drivlina. För detta ändamål kan datorstödda beräkningar användas för att utvärdera ett stort antal konfigurationer. Dessa beräkningar är, i bästa fall, endast så bra som de använda materialmodellerna. Inom en överskådlig framtid kommer gummi med förstärkande fyllmedel användas i vibrationsisolatorer för att erhålla de önskade egenskaperna hos dessa komponenter. Men styvheten och dämpningen i gummi med förstärkande fyllmedel är kraftigt icke-linjära funktioner, och de tillgängliga materialmodellerna i kommersiella programvaror och i litteraturen är ofta otillräckliga. Därför är en viskoplastisk materialmodell för finita deformationer framtagen i tidsdomänen och implementeras som ett användardefinierat material i Abaqus Explicit. Modellen fångar töjningsamplitud- och frekvensberoendet av lagrings- och förlustmodulen för ett kimröksfyllt naturgummi. Den är korrekt över ett brett intervall av skjuvtöjningsamplituder och frekvenser, 0.2-50% respektive 0.5-20 Hz, och kräver endast 5 materialparametrar. Dessutom fångar modeller responsen från bimodala excitationer. Implementeringen i Abaqus Explicit gör att komponentegenskaper kan utvärderas tidigt i utvecklingsfasen, med materialparametrar som härrör från enkla provkroppar. Den förbättrade noggrannheten i simuleringar av dessa komponenter kan hjälpa ingenjörer att utveckla mer optimerade lösningar snabbare än med konventionella metoder.
QC 20160406
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Tan, Stella. "Assessing near-field black carbon variability due to wood burning and evaluating regression models and ISC dispersion modeling." DigitalCommons@CalPoly, 2011. https://digitalcommons.calpoly.edu/theses/626.
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PM2.5 variability within the neighborhood scale has not been thoroughly studied for wood burning communities. High variability in near-field PM2.5 concentration may lead to harmful public exposure since monitoring does not occur on that scale. This study measures near-field PM2.5 variability by measuring black carbon (BC), a component of PM2.5, in a 1 km2 area located in Cambria, California. BC and meteorological data (when meteorological instruments were available) were measured over thirteen 12-hour intensive operation periods (IOPs) occurring over the winters of 2009 and 2010. Near-field BC variability was measured to understand the type of exposures found in communities where many homes are burning wood simultaneously within a small area. In addition, relationships between meteorological, geographical, and burning source characteristics and BC were observed as tools for understanding BC concentration. The computer air dispersion modeling programs, ISC-PRIME and ISCST3, were also evaluated for applicability to the near field.
BC concentrations were measured using 1- to 2-minute resolution aethalometers and 12 hour resolution Personal Environmental Monitors (PEMs). On average, over all IOPs and sites, aethalometer and PEM BC averages were very similar, ranging between 200 and 250 ng/m3, or 4 and 5 µg/m3 for PM2.5, and standard deviations were often high. Averaging all BC measurements, aethalometer BC standard deviation values were 360 percent of the average BC concentration and PEM BC standard deviations were 120 percent the average BC concentration. The average standard deviation detected during each IOP was 190 percent of the average BC concentration for aethalometers and 79 percent of the average BC concentration for PEMs. The average standard deviation detected at each site was 220 percent of the average BC concentration for aethalometers and 76 percent of the average BC concentration for PEMs. The larger standard deviations measured by higher resolution aethalometers demonstrated that low resolution instruments, such as PEMs, are unable to detect high concentrations that may occur.
In addition to examining BC variability, multiple linear regression analyses were conducted to determine the impact of meteorological variables and geographic and burning source characteristics on BC concentration and a weighted BC deviation function (BC standard deviation divided by average BC concentration). Time impacts, humidity, and wind speed, accounted for about 50 percent of variability in aethalometer average BC and BC deviation. However, because all model assumptions were not satisfied, improvements are needed. Regression models based on PEM BC found wind speed and direction to account for about 80 percent of average PEM BC variability and number of burning sources to account for about 30 percent of PEM BC deviation. Although PEM BC models accounted for a high percentage of BC variability, few data points were available for the PEM analyses and more IOPs are needed to determine their accuracy.
When evaluating correlations between geographic and burning source characteristics and PEM BC concentrations, specific IOP and PEM sampling location explained almost 70 percent of variability in BC concentration, though model residuals suggested model bias. IOP likely explained variation in burning patterns and meteorology over each night while sampling location was likely a proxy for housing density, tree coverage, and/or elevation. Because all regression model assumptions could not be satisfied, the predictors were also observed graphically. Plotting BC concentration versus the number of burning sources suggested that number of burning sources may affect BC concentration in areas of low tree coverage and high housing density and in the case that the level of surrounding vegetation and structures are minimal. More data points will be needed to determine whether or not these relationships are significant.
ISC-PRIME and ISCST3 modeling overall tended to under predict BC concentrations with average modeled-to-measured ratios averaging 0.25 and 0.15, for ISC-PRIME and ISCST3, respectively. Correction factors of 9.75 and 18.2 for ISC-PRIME and ISCST3, respectively, were determined to bring modeled BC concentrations closer to unity, but the range of ratios was still high. Both programs were unable to consistently capture BC variability in the area and more investigation will be needed to improve models.
The results of the study indicate high BC variability exists on the near-field scale, but that the variability is not clearly explained by existing regression and air dispersion models. To prevent public exposure to harmful concentrations, more investigation will be needed to determine factors that largely influence pollutant variability on the neighborhood scale.
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Sun, Weicheng. "Use of Torrefied Sorghum as Eco-friendly Filler in Styrene Butadiene Rubber." University of Akron / OhioLINK, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=akron1527786418607651.
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ZOU, YU. "USE OF PYROLYZED SOYBEAN HULLS AS ECO-FRIENDLY REINFORCEMENTFILLER IN STYRENE BUTADIENE RUBBER." University of Akron / OhioLINK, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=akron1563924572380389.
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Agharkar, Amal. "Model Validation and Comparative Performance Evaluation of MOVES/CALINE4 and Generalized Additive Models for Near-Road Black Carbon Prediction." University of Cincinnati / OhioLINK, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1490350586489513.
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Liang, Marissa Shuang. "Quantitative Analysis of Major Factors Affecting Black Carbon Transport and Concentrations in the Unique Atmospheric Structures of Urban Environment." University of Cincinnati / OhioLINK, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1406819576.
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Al-Quraishi, Ali Abdul Hussain. "The Deformation and Fracture Energy of Natural Rubber Under High Strain Rates." University of Akron / OhioLINK, 2007. http://rave.ohiolink.edu/etdc/view?acc_num=akron1185471043.
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Österlöf, Rickard. "Modelling of the Fletcher-Gent effect and obtaining hyperelastic parameters for filled elastomers." Licentiate thesis, KTH, MWL Strukturakustik, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-151304.
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The strain amplitude dependency , i.e. the Fletcher-Gent effect and Payne effect, and the strain rate dependency of rubber with reinforcing fillers is modelled using a modified boundary surface model and implemented uniaxially. In this thesis, a split of strain instead of stress is utilized, and the storage and loss modulus are captured over two decades of both strain amplitudes and frequencies. In addition, experimental results from bimodal excitation are replicated well, even though material parameters were obtained solely from harmonic excitation. These results are encouraging since the superposition principle is not valid for filled rubber, and real-life operational conditions in general contain several harmonics. This means that formulating constitutive equations in the frequency domain is a cumbersome task, and therefore the derived model is implemented in the time domain. Filled rubber is used irreplaceable in several engineering solutions, such as tires, bushings, vibrations isolators, seals and tread belts, to name just a few. In certain applications, it is sufficient to model the elastic properties of a component during finite strains. However, Hooke’s law is inadequate for this task. Instead, hyperelastic material models are used. Finally, the thesis presents a methodology for obtaining the required material parameters utilizing experiments in pure shear, uniaxial tension and the inflation of a rubber membrane. It is argued that the unloading curve rather than the loading curve is more suitable for obtaining these parameters, even at very low strain rates.QC 20140917
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Andreu, Aurik Yann. "Specific and non-specific interactions on carbon material surfaces." Thesis, Robert Gordon University, 2010. http://hdl.handle.net/10059/566.
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The interactions which occur between both polar and non-polar fluid phases and surfaces of various carbon materials: Activated Carbon (AC), non-porous Carbon Black (CB) and Multiwall Carbon Nanotubes (MWCNTs)with different surface chemistry have been studied. These are currently of great interest as they govern the interfacial behaviour of carbons in a wide range of applications; separation adn composite technologies being two prime examples. Consequently, techniques for chemical modification of carbon surfaces ar also of interest. Surface oxygen functional groups have been introduced, or modified, using the following oxidation techniques: liquid-phase oxidation (both AC and CB), Fenton and Birch reduction treatment (MWCNTs) and in a more controlled manner using gas-phase ozone treatment (CB). The chemistry of all the resulting carbon surfaces were characterised using X-ray Photoelectron Spectroscopy (XPS), which gives a quick and direct quantitative measure of the external surface composition. This technique, which has not yet been extensively employed in detailed adsorption studies, is a promising alternative to Temperature Programmed Desorption (TPD) and Boehm titration method in the determination of oxygen and other surface groups. Physical effects of the various surface modifications have been studied using a variety of techniques appropriate for the material in question. Scanning Electron Microscopy (SEM) images show some deteriorating effects of the liquid-phase oxidations on the structure of both activated carbon and carbon black materials. Conversely, surface areas from nitrogen adsorption at 77oK, coupled witj immersion calorimetry data for toluene, show thet the physical structure of the carbon blacks is not modified by ozone treatment. This has allowed a detailed study of the effects of surface oxygen level (i.e. polarity) on vapour adsorption. Regarding the MWCNT materials, detailed High-Resolution Electron Microscopy (HRTEM) photographs show that the multi-wall structure of the nanotubes in not significantly disrupted during the introduction of active functional groups by the Fenton or Birch treatment and therefore keeping intact their mechanical properties which augurs well for their use as reinforcement in composite structures whilst also improving their dispersion properties in polar fluids. A systematic shift to higher adsorption values, due to the increasing specific interactions between the alcohol -OH groups and the surface oxygen groups, is observed in all the isotherms of alcohols from the CB series as the total surface oxygen concentration ([O]T) increases. Moreover, this effect was observed to be most significant for methanol confirming that the mechanism of adsorption is dominated by hydrogen bonding and therefore dependant on the surface concentration of oxygen sites; whereas it becomes less marked in the case of ethanol and isopropanol respectively due to the increasing non-specific, dispersion, interactions of the alkyl chain with the non-polar carbon surface. Overall correlations were observed between the surface oxygen concentration [O]T, the resulting enthalpy of immersion -^Hi values and the characteristic energy E of the Dubinin-Radushkevich-Kaganer (DRK) equation obtained for toluene and these alcohols and the influence of the carbon surface chemistry on the character of the adsorption isotherms is also discussed. This behaviour is also observed and much more pronounced in the case of water adsorption on other oxidised carbon materials (AC, CB and MWCNT) due to the higher polarity of water molecules. The water adsorption data were analysed using in particular the Dubinin-Serpinsky (DS) equation and also some of its recent variations such as Barton and D'Arcy & Watt equations. The DS2 and various Barton equations were found to fit best the AC and CB materials modified by liquid-phase oxidations and also for the CB 03 series with increasing level of oxidation while both D'Arcy & Watt equations gave the best fittings for the MWCNTs materials. It was also shown that the resulting parameters ao (for the DS equation) describing the surface concentration of primary polar adsorption sites and as the limiting water adsorption value were both linked to the surface oxygen level [O]T. Regarding interfacial bonding, the oxidised CB and MWCNT materials are expected to show an improved physicochemical wetting of their surfaces by various resin compunds
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Alves, Aguinaldo Lenine [UNESP]. "Preparação e caracterização de compósitos condutores obtidos a partir da borracha natural com raspa de couro e negro de fumo." Universidade Estadual Paulista (UNESP), 2009. http://hdl.handle.net/11449/100910.
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Compósitos condutores são materiais preparados para combinar as propriedades físicas dos polímeros com partículas condutivas. Neste trabalho, são apresentadas a preparação e caracterização de compósitos condutores contendo borracha natural (BN), raspa de couro (RC) e negro de fumo (NF). As Amostras foram conformadas em diferentes percentuais em massa dos constituintes BN, RC e NF: 38/60/2.0; 37.5/60/2.5; 37/60/3.0 e 36.5/60/3.5, respectivamente, aplicando uma pressão de 12 toneladas durante o 5 minutos à temperatura de 160°C, resultando em membranas com boa qualidade e com a espessura desejada. Os compósitos BN/RC/NF foram caracterizados por microscopia óptica (MO), microscopia eletrônica varredura (MEV), Microscopia de Força Atômica (AFM), espectroscopia Raman e infravermelho, termogravimetria (TG), calorimetria exploratória de varredura (DSC), análise dinâmico mecânica (DMA), testes mecânicos (Tensão versus deformação) e medidas de condutividade elétrica. A presença do NF no compósitos BN/ RC/NF, promoveu uma condutividade elétrica da ordem de 1.5x10-3 S.cm-1. Os ensaios mecânicos mostram que o compósito BN/RC/NF possui propriedades físicas intermediárias entre as membranas de BN e o couro. Verificou-se que as membranas do compósito BN/RC/NF são de baixo custo, e podem ser facilmente preparadas. Estes compósitos apresentaram boa estabilidade térmica, adequadas propriedade mecânica e condutividade elétrica, e são apropriadas para produzir luvas, mantas e pisos antiestáticos. Além disso, o compósito BN/RC/NF são obtidos a partir de resíduos de curtumes de couro contribuindo para a redução de um problema ambiental.
Conductive composites are materials prepared combining the physical properties of polymers and conductive particles. In this work the preparation and characterization of conducting composites containing natural rubber (NR), leather residue (LR) and carbon black (CB) are presented. Samples were conformed in different percentages of mass of the NR, LR and CB constituents: 38/60/2.0; 37.5/60/2.5; 37/60/3.0 and 36.5/60/3.5, respectively, applying a pressure of 12 tons during 5 minutes at the temperature of 160°C, resulting in membranes with good quality and with the desired thickness. The NR/LR/CB composites were characterized using optical microscopy (OM), scanning electronic microscopy (SEM), atomic force microscopy (AFM), Raman and infrared spectroscopy, thermogravimetry (TG), differential scanning calorimetry (DSC), dynamic mechanical analysis (DMA), mechanical test (stress vs. strain) and he electric conductivity measurements. The presence of the CB in composites NR/LR/CB provided an electric conductivity of the order of 1.5x10-3 S.cm-1. Mechanical tests show that the NR/LR/CB composites have intermediate properties between the membranes of NR and the leather. It was found that NR/LR/CB membranes can be easily prepared with very low cost. They presented good thermal stability, adequate mechanical and electric conductivity properties that are appropriate to produce gloves, blankets and antistatic floors. In addition, the NR/LR/CB composites are obtained from leather residues from tanneries contributing for the reduction of an environmental problem.
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Crié, Alice. "Caractérisation et lois rhéologiques d’élastomères chargés à basse température pour la simulation du procédé d’extrusion." Thesis, Paris, ENMP, 2014. http://www.theses.fr/2014ENMP0085/document.
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Ce travail de thèse porte sur l'étude du comportement rhéologique de deux mélanges élastomères chargés en noir de carbone dans une gamme de températures rencontrée en extrusion (90°C à 40°C) et sur la modélisation du procédé d'extrusion. La caractérisation rhéologique des deux matériaux de l'étude a mis en évidence leur comportement rhéologique différent. En effet, le SBR et ses mélanges chargés avec différentes teneurs en noir de carbone montrent une courbe d'écoulement en deux branches stables (branche I et branche II) séparées par un plateau. La présence d'un glissement, faible en branche I et important en branche II, a été mis en évidence. Le second matériau, le NR (pur et chargé), montre, quant à lui, un comportement en deux parties distinctes : une partie sans rhéodurcissement et une autre avec rhéodurcissement dû à la mise en place d'une cristallisation sous contrainte de cisaillement. L'existence d'un temps caractéristique de cristallisation, diminué par la vitesse de cisaillement, a pu être mise en évidence. Les lois de comportement pour chacun des matériaux ont été déterminées. La réalisation d'une superposition temps/taux de charge a permis de définir une loi de comportement générale ; dans la gamme de température de 40°C à 90°C pour les mélanges SBR/noir de carbone et dans la gamme de température de 50°C à 90°C pour le NR. La loi rhéologique déterminée pour le mélange SBR chargé à 33% en masse en noir de carbone a été implémentée dans un modèle 1D et 3D. Les résultats numériques ont alors été comparés aux résultats expérimentaux, obtenus suite à des essais sur une extrudeuse instrumentée. Le modèle 1D s'est avéré insuffisant pour rendre compte des phénomènes se déroulant lors du procédé d'extrusion. L'implémentation d'un modèle 3D a été effectuée afin de prendre en compte des phénomènes tels que les effets de bords et les gradients de températures. L'importance de prendre en compte le phénomène de glissement dans le modèle 3D a été démontréeThe present work deals with the characterization of the rheological behaviour of two rubbers filled with carbon black in a range of temperature encountered in extrusion (90°C to 40°C) and the modelling of the single screw extrusion process. The rheological characterization of the two rubbers shows behaviour totally different. The synthetic SBR rubber and SBR compounds filled with carbon black (with different amounts, from 16 to 33 wt%) showed a flow curve that can be divided in two stable parts (branch I and branch II) separated by a plateau. The occurrence of wall slip, low in branch I and important in branch II has been highlighted. The second rubber of the study, natural rubber, showed a different behaviour with a strain hardening due to the occurrence of a strain induced crystallization. The flow curve can be thus divided in two different parts: the first part without strain hardening and the second part with this phenomenon. The existence of a characteristic crystallization time, reduced by the shear rate, has been evidenced. By analysing data respectively on branch I for SBR and without strain hardening for NR, viscosity curves for all tested materials have been defined. General viscosity law have been proposed: for the SBR compound filled with carbon black valid in the range of temperature from 40°C to 90°C and for NR in the range of temperature from 50°C to 90°C. The rheological law defined for the SBR compound filled 33%wt with carbon black has been implemented in two different models: 1 D and 3D. Numerical results have been compared to experimental results obtained after experimentations on instrumented single screw extruder. The 1D approach was not sufficient to take into account all phenomena occurring during extrusion process. Then a 3D approach has been developed in order to take into account some effects as side effects and temperature gradients. The presence of the slip phenomenon in the modeling has been proved
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Merlin, Marie. "Structure et propriétés de mélanges d'élastomères chargés de noir de carbone : étude des coupages NR / SBR et BR / SBR." Phd thesis, Université Jean Monnet - Saint-Etienne, 2012. http://tel.archives-ouvertes.fr/tel-00952025.
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Les objectifs de cette thèse consistent à identifier les morphologies adoptées par des mélanges d'élastomères chargés en noir de carbone, à étudier l'influence de l'introduction de charges sur ces morphologies mais aussi de détecter la localisation de la charge dans ces mélanges. Dans une dernière partie, l'impact de ces différentes structures sur les défauts d'extrusion est abordé. Ces travaux concernent l'étude des coupages caoutchouc naturel / styrene-butadiene rubber (NR / SBR) et polybutadiène / styrene-butadiene rubber (BR / SBR) non vulcanisés. Dans un premier temps, les morphologies adoptées par ces mélanges non chargés ont été identifiées grâce à plusieurs protocoles expérimentaux. L'influence de l'introduction de noir de carbone ainsi que l'étude de la localisation de la charge dans ces mélanges ont constitué une seconde étape dans ces travaux. Aucune localisation préférentielle de la charge n'a été détectée pour ces mélanges. Un système ségrégé a donc été réalisé par la suite. Enfin, le comportement en extrusion de ces mélanges a été simulé par rhéométrie capillaire et des observations de défauts d'aspect ont été faites. La ségrégation du noir de carbone ne semble pas entraîner la création de défauts d'aspect, sauf dans le cas d'une localisation dans la matrice
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Vidal, Escales Eduard. "Influència de l'activitat superficial dels diferents components d'una formulació de cautxú en la reacció de vulcanització." Doctoral thesis, Universitat Ramon Llull, 2007. http://hdl.handle.net/10803/9289.
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L'estudi de la reacció de vulcanització en presència de càrregues mostra la influència de la superfície del negre de carboni a la reacció de vulcanització, i més concretament de l'activitat superficial del negre de carboni. Aquest estudi de la influència a la vulcanització s'amplia a altres paràmetres com la microestructura superficial del negre de carboni. Els resultats mostren un efecte d'activació de la reacció a major superfície específica, a major activitat superficial i en especial de la major component polar de la superfície. Per tal de millorar el seguiment de la reacció de vulcanització s'ha desenvolupat una metodologia analítica d'HPLC. Aquest mateix procés a la superfície del negre de carboni s'ha estudiat mitjançant ToF-SIMS, confirmant-se com una eina útil per al seguiment dels intermedis de reacció a la superfície de la càrrega.
Finalment, s'ha modificat l'activitat superficial d'alguns dels components de la vulcanització, en aquest cas l'accelerant i el sofre, mitjançant polimerització amb plasma fred per tal d'estudiar-ne l'efecte a la vulcanització i el seu comportament al sí de la mescla. En el cas de l'accelerant els resultats mostren la possibilitat de modificar l'activitat de l'accelerant a la vulcanització sense alterar les propietats finals del producte. Pel que respecta a la modificació del sofre, els resultats obren les portes a un camí de tractament superficial de les partícules de sofre per a reduir l'efecte de migració del sofre.
El estudio de la reacción de vulcanización en presencia de cargas muestra la influencia de la superficie del negro de carbono en la reacción de vulcanización, y más concretamente de la actividad superficial del negro de carbono. Este estudio de la influencia en la vulcanización se amplia a otros parámetros como la microestructura superficial del negro de carbono. Los resultados muestran un efecto de activación de la reacción a mayor superficie específica, a mayor actividad superficial y en especial de la mayor componente polar de la superficie.
Para mejorar el seguimiento de la reacción de vulcanización se ha desarrollado una metodología analítica de HPLC. Este mismo proceso en la superficie del negro de carbono se ha estudiado mediante ToF-SIMS, confirmándose como una herramienta útil para el seguimiento de los intermedios de reacción en la superficie de la carga.
Finalmente, se ha modificado la actividad superficial de algunos de los componentes de la vulcanización, en este caso el acelerante y el azufre, mediante polimerización con plasma frío para estudiar el efecto en la vulcanización y su comportamiento en el sí de la mezcla. En el caso del acelerante los resultados muestran la posibilidad de modificar la actividad del acelerante en la vulcanización sin alterar las propiedades finales del producto. Referente a la modificación del azufre, los resultados abren las puertas a un camino de tratamiento superficial de las partículas de azufre para reducir el efecto de la migración del azufre.
The study of the vulcanization in the presence of fillers shows the carbon black surface influence on the vulcanization reaction and specially its surface activity component. These studies have been opened to other parameters like the microstructure of the carbon black surface. Results show the activation effect of the vulcanization reaction at higher surface activity and specially at higher polar component.
To improve the following of vulcanization reaction it has been developed a new analytical HPLC methodology. The same process on the carbon black surface has been studied by ToF-SIMS, and it has been demonstrated to be a useful technique to follow the vulcanization reaction.
Taking in account the significance of surface activity, surface activity of some components like the accelerator and sulfur has been modified by cold plasma polymerization in order to study the effect on the vulcanization and the behavior in the mix. Concerning the accelerator, results show that it's possible to modify the accelerator performance without modifying the properties of the rubber goods. Sulfur surface activity treatment results open a new field for surface activity treatments to minimize the blooming effect.
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Mané, Zélie. "Détermination et étude des mécanismes mésoscopiques responsables de l'usure des caoutchoucs naturels renforcés." Thesis, Ecully, Ecole centrale de Lyon, 2011. http://www.theses.fr/2011ECDL0030.
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Dans des conditions de conduite dite douce, la bande de roulement de pneumatique présente des faciès d’usure de type cratères d’usure ou bien des rides.Le but de ce travail de thèse était de recréer et d’étudier ces faciès d’usure pour des élastomères renforcés par du noir de carbone ou de la silice sur un tribomètre rotatif afin de pouvoir expliquer leurs mécanismes de formation. Des parallèles ont été établis entre les valeurs de perte de masse, de coefficient de frottement et le type du faciès d’usure tout en prenant en compte les propriétés physico-chimiques des échantillons.L’étude a expliqué les différences entre les types de faciès d’usure générés sur des matériaux renforcés par du noir de carbone et ceux renforcés par de la silice. Les paramètres influant sur a transition cratères d’usure et rides ont également été étudiésIn soft conditions of driving, wear patterns appear on the tire tread. They are called wear craters and ridges.The aim of this thesis work was to recreate and to study these wear patterns for reinforced elastomers by carbon black or silica on a rotary tribometer in order to explain their mechanisms formation. Parallels were established between the values of mass lost, friction coefficient and the type of wear patterns while taking into account the physico-chemical properties of samples.The study explained the differences between the type of wear patterns generated on reinforced materials by carbon black and those reinforced by silica. Affect parameters on the transition between wear craters and ridges were also studied
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Nozet, Quentin. "Structure et propriétés de matériaux composites obtenus par hétérocoagulation de latex de caoutchouc naturel et de noir de carbone." Electronic Thesis or Diss., Université Paris sciences et lettres, 2020. http://www.theses.fr/2020UPSLS033.
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Cette thèse étudie le phénomène de durcissement qui a lieu pendant le stockage des composites de latex de caoutchouc naturel et de noir de carbone fabriqués par hétérocoagulation. Ce procédé consiste à injecter à très grande vitesse une suspension aqueuse de noir de carbone dans du latex de caoutchouc naturel. Le matériau spongieux et très hydraté qui est obtenu est ensuite séché et mis en forme par malaxage ou pressage. Nous mesurons le durcissement des composites à l’aide de plusieurs méthodes rhéologiques parmi lesquelles la rhéologie de torsion et la viscosimétrie de Mooney. L’effet d’un grand nombre de paramètres est étudié : le mode de mise en forme des composites, l’environnement du stockage, la présence d’eau résiduelle, la température, la fraction massique de noir de carbone. Nous définissons des temps caractéristiques de durcissement dont la dépendance en température indique que le durcissement résulte d’un processus activé thermiquement. Les énergies d’activation sont peu dépendantes des paramètres expérimentaux et comparables à celle trouvée pour le caoutchouc naturel pur. Des expériences de gonflement en bon solvant montrent que le durcissement est associé à la formation d’un réseau de macromolécules interconnectées dont nous discutons l’origine en relation avec la microstructure du polyisoprène naturel et la présence de phospholipides et de protéinesThis thesis investigates the storage hardening of natural rubber and carbon black composites made by heterocoagulation. Heterocoagulation is a process that consists in injecting a carbon black slurry at high speed into a colloidal suspension of natural rubber. We obtain a squishy and highly hydrated material that is subsequently dried and processed using an internal mixer or a mechanical press. The hardening is characterized using various rheological techniques among which torsional rheology and Mooney viscosimetry. Many parameters are investigated: the processing technique, the storage environment, the presence of residual water, temperature, the carbon black content. We define characteristic times of hardening whose temperature dependence indicates that the hardening results from a activated process. The energies of activation are nearly independent of the experimental parameters and compare well to that found in natural rubber. Swelling experiments in good solvent show that hardening is associated with the buildup of an interconnected network of macromolecules. We discuss the origin of this network in relation with the microstructure of natural polyisoprene and the presence of phospholipids and proteins
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Frébourg, Philippe. "Mélanges noir de carbone-polybutadiène : étude par RMN du proton, extraction et gonflement." Université Joseph Fourier (Grenoble), 1994. http://www.theses.fr/1994GRE10205.
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Les systemes etudies sont constitues d'agregats de noir de carbone n220 interconnectes par des chaines polybutadiene absorbees a leur surface. Nous les caracterisons par extraction, rmn et gonflement. Les mesures du taux de polymere residuel apres extraction et la modelisation de l'adsorption par la percolation nous permettent d'estimer la proportion de chaines faiblement fixees et desorbees lors du sejour en solvant. D'autre part, les proprietes rmn de ces systemes conduisent a une caracterisation fine de la statistique d'adsorption sur differentes echelles d'espace: au niveau de l'interface charge-polymere, nous mettons en evidence une proportion de monomeres adsorbes remarquablement faible, de l'ordre de 2%. Au niveau de l'interphase, nous montrons que la structure en boucles des chaines adsorbees depend fortement de l'histoire des echantillons. En fin d'extraction et avant sechage cette structure est tres lache et le nombre de points d'absorption par chaine est independant de leur longueur. Par contre, apres sechage l'interphase s'est densifiee de facon irreversible et ce nombre devient proportionnel a la racine carree de la longueur des chaines. Enfin, le gonflement, decrit dans l'approche en champ moyen de flory, apporte des informations complementaires sur la texture des melanges. L'ensemble des resultats experimentaux obtenus conduit a une representation globale et coherente de l'organisation microscopique de ces systemes
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Munsch, Jean-Nicolas. "Etude d'adsorption HNBRs par microcalorimetrie à écoulement sur des noirs de carbones ou des silices modifiées ou non et son influence sur les propriétés du polymère chargé." Thesis, Mulhouse, 2014. http://www.theses.fr/2014MULH7493/document.
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L’usage des élastomères en tant que matériau ne peut se concevoir sans l’utilisation de certaines charges dites renforçantes. Bien qu’une variété plutôt large de minéraux en poudre puisse être associée aux élastomères, deux charges sont très majoritairement utilisées de par leur haute capacité renforçante, les noirs de carbone et les silices actives et hautement structurées. L’utilisation de la silice n’a été envisagée, à partir des années 1980, que grâce à un contrôle fin de sa chimie de surface, de ses silanols hydrophiles et de son traitement par silanes spécifiquement dessinés pour satisfaire une application précise. La preuve expérimentale quantifiant les interactions charge – polymère est grandement souhaitée. C’est précisément le premier but que cette thèse tente d’approcher. Pour tenter d’atteindre cet objectif, nous proposons d’étudier dans ce travail l’évaluation de l’adsorption d'un polymère, une série de HNBR, sur des charges, noir de carbone et silice traitée ou non par des silanes spécifiquement désignés, d’un point de vue énergétique et moléculaire au moyen de la microcalorimétrie à écoulement (FMC). L'application de cet outil, relativement connu dans le cadre des interactions petite molécule – charge est plutôt original dans l’étude des couples polymère – charge. Notre deuxième but est donc, et grâce à une connaissance fine de la chimie des surface d'une silice, de ses traitements par des silanes, et de l'adsorption du polymère sur sa surface, d'explorer la corrélation entre le traitement et les propriétés macroscopiques dans le but d'établir une relation de cause à effetMost actual uses of elastomers are not even conceivable without the assistance of reinforcing filler. In this field, "silane-technology" brought into evidence the necessity of monitoring the competition that routinely rises between two determinant factors: polymer-filler interactions and filler-filler interactions. As a result, an important database founded essentially on the characterization of the surfaces chemistry and surface energy of the two antagonist elements had to be gathered. However, the determination of the consequence of such characters on the factual polymer-filler interactions remains rudimentary, such as bound rubber gravimetric measurements. Experimental prove which is able to quantify such interactions is badly needed. This is, actually, the first objective that we tried to achieve. In order to do so, we propose in this work to study, from the energy point of view using flow micro calorimeter (FMC), the evolution of the adsorption of a series of HNBR on the surface of carbon black (CB) and silicas unmodified and modified by selected silanes. If the goal of the silane technology is to design coupling agents that are able to satisfy a specific application, especially those related to the energy dissipation, the mechanism through which such a process is achieved is not fully understood. Thus, and based on a fine knowledge of surface chemistry, surface treatments and polymer adsorption, our second objective is to explore the cause-to-effect links that ought to exist between filler surface treatments and blends macroscopic properties
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Candau, Nicolas. "Compréhension des mécanismes de cristallisation sous tension des élastomères en conditions quasi-statiques et dynamiques." Thesis, Lyon, INSA, 2014. http://www.theses.fr/2014ISAL0057/document.
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La cristallisation sous tension (SIC) du caoutchouc naturel (NR) a fait l’objet d’un nombre considérable d’études depuis sa découverte il y a près d’un siècle. Cependant, il existe peu d’informations dans la littérature concernant le comportement du caoutchouc à des vitesses de sollicitation proches des temps caractéristiques de cristallisation. L’objectif de cette thèse est alors de contribuer à la compréhension du phénomène de cristallisation sous tension grâce à des essais dynamiques à grandes vitesses. Pour répondre à cet objectif, nous avons développé une machine de traction permettant de déformer des échantillons d’élastomères à des vitesses de sollicitation pouvant aller jusqu’à 290s-1. Les essais ont été réalisés sur quatre NR avec des taux de soufre variables, deux NR chargés comportant des taux de noir de carbone différents. Nous avons également étudié un matériau synthétique à base de polyisoprène (IR) afin de comparer ses performances à celle du NR. Les essais dynamiques étant relativement difficiles à interpréter, un travail conséquent a donc été d’abord réalisé à basse vitesse. En outre, l’approche expérimentale proposée a été couplée à une approche thermodynamique de la SIC. Les mécanismes généraux associés à la cristallisation que nous identifions sont les suivants: lors d’une traction, la cristallisation consiste en l’apparition de populations cristallines conditionnée par l’hétérogénéité de réticulation des échantillons. Cette cristallisation semble nettement accélérée dès lors que ce cycle est réalisé au-dessus de la déformation de fusion. Nous attribuons ce phénomène à un effet mémoire dû à un alignement permanent des chaînes. Enfin, l’effet de la vitesse est décrit théoriquement en intégrant un terme de diffusion des chaînes dans la cinétique de SIC. Cette approche couplée à des essais mécaniques suggère que la SIC est essentiellement gouvernée par la cinétique de nucléation. Lors des tests dynamiques, la combinaison de l’effet mémoire et d’une accélération de la fusion pendant le cycle entraine une nette diminution voire une disparition de l’hystérèse cristalline. En outre, l’auto-échauffement, qui augmente progressivement avec la fréquence du cycle, tend à supprimer l’effet mémoire en provoquant le passage du cycle en dessous de la déformation de fusion. Lors de ces essais dynamiques, la SIC semble favorisée pour le matériau le moins réticulé. Nous attribuons cet effet au blocage d’enchevêtrements jouant le rôle de sites nucléants pour la SIC. Le matériau chargé semble avoir une moins bonne aptitude à cristalliser à hautes vitesses, par rapport à l’élastomère non chargé, en raison d’un auto-échauffement important à l’interface entre charges et matrice. Enfin, nous notons une convergence des cinétiques de cristallisation du caoutchouc naturel et synthétique à grande déformation et grande vitesse de sollicitation, que nous attribuons à la prédominance du terme énergétique d’origine entropique dans la cinétique de nucléationStrain induced crystallization (SIC) of Natural Rubber (NR) has been the subject of a large number of studies since its discovery in 1929. However, the literature is very poor concerning the study of SIC when samples are deformed with a stretching time in the range of the SIC characteristic time (around 10msec-100msec). Thus, the aim of this thesis is to contribute to the understanding of the SIC phenomenon thanks to dynamic tensile tests at high strain rates. To meet this goal, we have developed a dynamic tensile test machine allowing stretching samples of elastomers at strain rates up to 290 s-1. The tests are carried out on four NR with different sulphur amount, two NR with different carbon black filler amounts. We also studied a synthetic rubber made of polyisoprene chains (IR) able to crystallize under strain. Dynamic tests are relatively difficult to interpret; a significant work has thus been first performed at slow strain rate. Moreover, the experiments are coupled with a thermodynamic approach. First, the general mechanisms associated to the crystallization are identified as follows: during mechanical loading or during cooling in the deformed state, SIC is the result of successive appearance of crystallite populations whose nucleation and growth depend on the local network density. Crystallization is enhanced when the cycle is performed above the melting stretching ratio. This phenomenon is attributed to a memory effect due to a permanent alignment of the chains. Finally, the effect of the strain rate is theoretically described thanks to a diffusion term. This approach, coupled with experiments suggests that SIC is mainly governed by the nucleation kinetics. For the dynamic test, the combination of the memory effect and the acceleration of the melting during the cycle lead to a reduction or even disappearance of the crystalline hysteresis. In addition, self-heating, which progressively increases with the frequency of the cycle, causes the delay of the melting stretching ratio. This well explains why the crystallinity index decreases at the minimum stretching ratio of the dynamic cycles when the frequency increases. We finally compared the ability of our different rubbers to crystallize at high strain rates. SIC is enhanced for the weakly crosslinked rubber. This might be related to the dynamics of its free entanglements, these ones acting as supplementary crosslinks at high strain rates. Then, a filled rubber is compared to the unfilled one. We found that the filled sample has a lower ability to crystallize at high strain rates as compared to the unfilled one. This is likely due to the strong self-heating at the interface between the fillers and the rubbery matrix. Finally, we observe a convergence of crystallization kinetics in natural and synthetic rubbers at high strains and high strain rates. This is attributed to the predominance of the entropic energy in the nucleation kinetics in these experimental conditions
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Roucou, David. "Caractérisation et modélisation du comportement à la déchirure de matériaux élastomères endommagés par chargements multiaxiaux." Thesis, Ecole centrale de Lille, 2020. http://www.theses.fr/2020ECLI0001.
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Les élastomères sont utilisés dans les systèmes mécaniques pour assumer des tâches de suspension ou de liaison, comme dans le cas des pneumatiques. Les élastomères d’intérêt sont renforcés par des particules de noir de carbone. L’ajout de charges améliore certaines propriétés mécaniques telles que la raideur ou la résistance à l’abrasion, mais induit aussi un fort adoucissement de ces matériaux, dit effet Mullins, lors de l’étirement initial. Certaines applications soumettent des élastomères à des sollicitations extrêmes, pouvant provoquer une fissuration critique.Ce travail étudie l’impact de l’adoucissement par effet Mullins sur la propagation de fissures lors de chargements monotones.Des résultats expérimentaux préliminaires font ressortir des difficultés à caractériser la fissuration dans les matériaux étudiés. Une méthode d’analyse locale est développée, estimant les champs de déformation fortement hétérogènes auxquelles sont soumises les éprouvettes pré-entaillées. Ces observations valident des hypothèses permettant le calcul du taux de restitution d’énergie, qui caractérise la fissuration. Une campagne expérimentale est menée pour évaluer l’impact de précharges variées sur la propagation de fissures dans un élastomère chargé au noir de carbone. Afin d’expliquer certains résultats obtenus, l’équilibre énergétique théorique inhérent à la propagation de fissure est réévalué pour prendre en compte le caractère dissipatif de l’adoucissement. Enfin, les mesures expérimentales de la déformation locale sont ensuite exploitées pour compléter le bilan énergétique, en caractérisant la dissipation énergétique localisée due à l’effet MullinsRubber-like materials are currently used in machine design for suspension or connection functions, such as pneumatic tyres. The elastomers of interest are reinforced by carbon-black particles. The addition of these particles improves mechanical properties such as stiffness and abrasion resistance. However, it also leads to undesired strong softening of these materials, commonly known as Mullins effect, when first stretched. Elastomers can be submitted to extreme loading conditions according to the applications, generating critical crack propagation.This works studies the impact of softening caused by Mullins effect on crack propagation in filled rubbers submitted to monotonic loading.Some early experimental results point out the difficulties to characterize a crack propagation criterion. A local analysis is developed, allowing to study the highly heterogeneous strain fields witnessed when loading notched specimens. These observations lead to the validation of assumptions, which enable to calculate the strain energy release rate that characterizes the crack propagation. An experimental campaign was then performed to evaluate the impact of various preloads on crack propagation in a carbon-black filled rubber. In order to explain some of the results obtained, the theoretical global energy balance when the crack propagation occurs was revisited in order to take into account the dissipation caused by the Mullins softening. Finally, the experimental measures of local strain were used to complete the energy balance and characterize the localized energy dissipation due to Mullins effect