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1
Matyumza, Ntombozuko C. "Improved filler retention by co-flocculation of fines and filler particles." Thesis, Stellenbosch : Stellenbosch University, 2005. http://hdl.handle.net/10019.1/37370.
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Thesis (MScFor)--Stellenbosch University, 2005.ENGLISH ABSTRACT: The retention of filler particles and drainage are important aspects of papermaking. A number of important paper properties depend in the quality and quantity of filler retained in the paper. Fines, fillers and pulp fibres all have a negative charge and are kept apart by electrostatic forces. This causes a decrease in the effectiveness of cationic retention aids thereby causing a high cationic demand. This in turn implies that the retention of fines and filler particles in a formed sheet is not efficient, especially in the presence of anionic trash. In order to improve printability, print quality and dimensional stability, a large percentage of mineral pigments / fillers either in the form of internal loading or external coating should be added. It was found that coflocculation of fines and filler particles resulted in an even distribution of filler particles in the form of miero-flocs and the filler retention was maintained. Opacity was improved without much reduction in paper strength. An increased filler content without coflocculation of fines reduced sheet strength properties. The filler particles interfered with the development of fibre-to-fibre bonds and occupied spaces that otherwise might have contained fibres. This study showed that the most beneficial effect of coflocculation of filler with fines was obtained, with regards to paper strength, opacity, filler retention and printability, when the charge of the fibre furnish was maintained at -0.1 leu with the 0.1% addition of cationic PAM retention aid.
AFRIKAANSE OPSOMMING: Twee belangrike aspekte van papiervervaardiging is die retensie van vulstowwe en ontwatering. 'n Aantal belangrike papiereienskappe is afhanklik van die hoeveelheid en kwaliteit van vulstowwe wat in papier voorkom. Veselpuin, vulstowwe en pulp-vesels is almal negatief gelaai, gevolglik verseker elektrostatiese kragte dat hierdie deeltjies los van mekaar bly. Laasgenoemde verminder die doeltreffendheid van kationiese retensiemiddels en dit gee aanleiding tot 'n hoë kationiese aanvraag. Die retensie van veselpuin en vulstof deeletjies in papier is gewoonlik nie voldoende in die teenwoordigheid van anioniese afvalkomponente nie. Om aan papier verbeterde drukeienskappe, drukkwaliteit en dimensionele stabiliteit te gee, moet 'n groot persentasie minerale pigmente en/of vulstowwe as 'n interne lading of eksterne bestryking voorsien word. Daar is bevind dat kot1okkulasie van fynstowwe en vulstofdeeltjies, 'n egalige verspreiding van vulstof-partikels as mikro-t1okke tot gevolg het en dat vulstof-retensie op aanvaarbare vlakke behou is. Ook is ondeurskynendheid verbeter sonder 'n beduidende verswakking in die papiersterkte. 'n Toename in vulstofinhoud, sonder kot1okkulasie van fynstowwe, het die papier sterkte-eienskappe verlaag. Vulstofdeeltjies bëinvloed die ontwikkeling van vesel-tot-vesel binding. Hierdie deeltjies beset ruimtes wat andersins deur vesels benut sou word. Hierdie studie het getoon dat die voordeligste effek van kot1okkulasie van vulstowwe met fynstowwe verkry is, ten opsigte van papiersterkte, ondeurskynendheid, vulstof retensie en drukeienskappe, wanneer die lading van die pulpsuspensie by -0.1 leu gehou was met 'n byvoeging van 0.1% kationiese PAM retensie-hulpmiddel.
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Gavroňová, Ivana. "Příprava a charakterizace vysoce plněných kompozitních systémů pro stomatologické aplikace." Master's thesis, Vysoké učení technické v Brně. Fakulta chemická, 2017. http://www.nusl.cz/ntk/nusl-295702.
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Master thesis deals with highly filled particulate composite materials for dental applications. In the practical part, the dimetacrylate matrix was filled with a mixture of particles of different types and different sizes to achieve the maximum possible packing. Moreover, filler content and the influence of filler on composite material was studied. Hydrolytic stability was also tested on composite materials. The methods used to characterize composite materials were bending test, thermogravimetric analysis (TGA), differential scanning photocalorimetry (DPC), dynamic-mechanical analysis (DMA) and scanning electron microscopy (SEM). Curing of the matrix was characterized by the degree of conversion, the heat of polymerization and the polymerization rate. Furthermore the polymerization shrinkage was measured. The glass transition temperature, the dynamic modulus at 40 °C and 100 °C, the modulus of elasticity, the strength, the critical value of the stress factor and the critical energy release rate were found in the tested samples.
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Hon, Amir Adam. "Modelling filler reinforcements in elastomers." Thesis, Queen Mary, University of London, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.420623.
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Kadlček, Jakub. "Hodnocení vlastností drobného kameniva pro asfaltové směsi." Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2018. http://www.nusl.cz/ntk/nusl-401473.
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The diploma thesis is focused on evaluation of properties of fine aggregate by means of laboratory tests. Fine aggregate evaluation was performed using sieving test, laser diffraction, delta ring and ball test, bitumen number test, uncompacted void content of fine aggregate according to AASHTO T 304, voids of dry compacted filler (Rigden) test and particle density of filler. Laboratory research has led to the discovery of some properties of fine aggregate and their dependencies.
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Jha, Vineetkumar. "Carbon black filler reinforcement of elastomers." Thesis, Queen Mary, University of London, 2008. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.510795.
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Wang, Xuyang. "Filler effects in resole adhesive formulations." Thesis, Virginia Tech, 2016. http://hdl.handle.net/10919/82499.
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This was a university/industry research cooperation with focus on how organic fillers affect the properties of phenol-formaldehyde resole (PF) resins that are formulated for veneer applications like plywood and laminated veneer lumber. The PF formulations studied in this work used fillers that were derived from walnut shell (Juglans regia), alder bark (Alnus rubra), almond shell (Prunus dulcis), and corn cob (furfural production) residue.
The chemical composition of all fillers was measured and compared to published data. The basic rheological behavior of the formulations was determined and used to develop an adhesive tack measurement based upon lubrication theory. In this work, the probe-tack test was adapted to a typical stress-controlled rheometer by using the normal force and displacement system to compress the adhesive between parallel plates. By employing a simple power law to describe the complex rheology of adhesives and a lubrication approximation for the viscous force, squeeze flow of adhesives between two flat, impermeable steels and between steel and porous wood can be successfully modeled. However, deviations from theory were encountered as related to the method of adhesive application. Both meniscus force in consequence of the surface tension of adhesive pull around the edge of plate and viscous force due to the viscosity of adhesive operate inside the meniscus when adhesive was spread on the entire surface by a hard roller.
manufacture where viscosity and surface tension effects were both involved. Last but not
Such is probably the case when wood veneer is cold-pressed (pre-pressed) in plywood
least, rheological behavior and alkali modification of wheat flour was determined by
rheological and infrared studies, respectively.Master of Science
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Mills, Stephen Leslie. "Assessment of filler dispersion using fractal analysis and its potential effect on the properties of polymer/filler composites." Thesis, Manchester Metropolitan University, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.298186.
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A novel technique for the assessment of dispersion quality in polymeric composites containing high levels of mineral filler or mixtures of different fillers is described. A comprehensive survey of the literature indicates that current methods of assessment using a combination of microscopy and image analysis are reliant on object specific measures which require good contrast between filler particles and the surrounding polymeric matrix. Such methods are inappropriate for the investigation of highly filled systems due to the presence of touching particles and poorly defined feature boundaries. The method described in this report uses characteristic X-rays or backscattered electron (BSE) imaging for the visualisation of filler dispersion patterns. The X-ray technique is especially useful for the discrimination of individual fillers in a multicomponent system. Multifractal analysis of X-ray or BSE images provides a quantitative description of dispersion quality using a numerical indicator derived from the width of the multifractal spectrum. The technique is successfully demonstrated on a series of flame retardant filler-EVA composites containing different amounts of ATH and Mg(OH)2. Linear models were constructed to illustrate the dependence of composite tensile strength and elongation at break on compound formulation and dispersion quality. Optimum material properties were observed for composites displaying good dispersion quality and predicted mechanical properties were compared against experimentally measured data. A positive correlation was found between real test data and predicted values. This technique provides a unique method for the dispersion assessmenot f mineral filled systems and can be performed on any SEM equipped with an EDX spectrometer and access to a PC running image analysis software. It is a useful addition to the current procedures available for the measurement of dispersion quality and should prove invaluable for the study of filled polymer systems.
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Fowler, Grant E. "Assessing the role of filler atoms in skutterudites and synthesis and characterization of new filled skutterudites." [Tampa, Fla] : University of South Florida, 2006. http://purl.fcla.edu/usf/dc/et/SFE0001708.
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Tauban, Mathieu. "Impact of Filler Morphology and Distribution on the Mechanical Properties of Filled Elastomers : theory and simulations." Thesis, Lyon, 2016. http://www.theses.fr/2016LYSE1069/document.
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Les nanocomposites présentent des propriétés uniques dont l'origine est sujette à débat. Dans ce travail, nous cherchons à déterminer quel est l'impact de la morphologie de la charge et de son état de distribution sur les propriétés des matériaux. Pour cela, nous avons étendu un modèle théorique que nous résolvons numériquement.Nous avons étudié l'effet de la distribution des charges dans la matrice. Nous montrons qu'un état de distribution fortement hétérogène conduit à un renforcement plus important qui s'étend dans une plus large gamme de températures, mais augmente aussi la dissipation d'énergie. Ensuite, nous étudions l'effet de la structure des charges. Des particules parfaitement sphériques sont comparées à des agrégats fractals plus ou moins finement définis. Nous montrons que des objets finement définis peuvent s'imbriquer au sein de la matrice et conduisent à une augmentation du renfort et de la dissipation dans ces matériaux.Puis, nous étudions la réponse de nos systèmes lorsqu'ils sont soumis à une première élongation de forte amplitude. Nous montrons alors qu'un système hétérogène se plastifie localement progressivement au cours de la déformation alors qu'un système homogène présente une plastification catastrophique généralisée à partir d'une déformation critique. Enfin dans une dernière partie nous évaluons la possibilité d'étendre le modèle afin de simuler l'endommagement des nanocomposites. Nous introduisons pour cela un critère rupture local afin de prendre en compte l'endommagement du polymère entre les charges. Nous étudions ensuite comment se comportent les matériaux simulés en faisant varier la morphologie de la charge, son état de distribution et son taux.Ce travail constitue la première étude systématique de l'effet de la morphologie et de la distribution des charges sur les propriétés mécaniques des nanocomposites. Nous montrons que ces paramètres peu contrôlés sont pourtant des paramètres clés et peuvent servir à optimiser les propriétés d’usage d'un nanocompositeNano-filled elastomer composites are used in a very broad range of applications such as tires, damping materials and impact modifiers. The addition of nanoscale rigid particles in a polymer matrix induces nonlinear effects that are not yet fully understood far above the glass transition temperature of the pure matrix. A model of the reinforcement of nanocomposites based on the reduced mobility of the polymer confined between two spherical filler particles has been developed over the last ten years. In order to study the influence of the filler shape, structure, size, and dispersion state, we have extended the model were the morphology of the fillers is defined explicitly as spherical particles aggregated in the polymer matrix. The model is then solved by mesoscale numerical simulation in order to describe the mechanical properties of the nanocomposite. We study the mechanical response of nanocomposite filled with aggregates of different shapes and distribution state to deformations of various amplitudes in the reinforcement regime. We show that the mechanical behavior of nanocomposites strongly depends on the filler morphology and we propose that stress-relaxation mechanisms in the material are related to the disorder (particle size, aggregation number, distribution state) in the filler population. In a second part of this work, we study the mechanical response at larger amplitude in both a non-destructive and destructive regime. For that matter, the model has been extended in order to account for damaging of the polymer between filler particles.Our model opens the path for the development of systems with tailored properties by adjusting the fillers morphology and distribution
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Rocha, Chrystianne. "Gap filler adaptativo para sistema ISDB-Tb." Universidade Presbiteriana Mackenzie, 2014. http://tede.mackenzie.br/jspui/handle/tede/1440.
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Previous issue date: 2014-08-07This master thesis presents the proposal of assigning the cognitive ability to a gap filler. Differently from the usual repeaters found on the market, the adaptive gap filler is able to automatically monitor tuned channels with the intention of verifying if the protection ratio described in Resolution nº398 from Anatel is being respected. Spectrum sensing techniques and the concepts related to coverage area will be addressed. Tests were carried out on the Matlab and GNU Radio Software with the purpose of analyzing the adaptive gap filler performance on real channels.
Este trabalho apresenta a proposta de atribuir ao gap filler a capacidade cognitiva . Diferentemente dos repetidores encontrados no mercado, o gap filler adaptativo tem como função monitorar, de forma autônoma, os canais sintonizados para verificar se a relação de proteção descrita na Resolução nº 398 da Anatel está sendo respeitada. Como fundamentos dessa proposta são abordadas as técnicas de sensoriamento do espectro e os conceitos relacionados às áreas de cobertura. Em uma abordagem prática, os testes foram desenvolvidos no Matlab e no GNU Radio, em que se analisa a atuação do gap filler adaptativo em canais reais.
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Mustafa-Kamal, Mazlina. "Starch as a filler for rubber compounds." Thesis, Loughborough University, 2007. https://dspace.lboro.ac.uk/2134/34216.
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Starch is a reasonably cheap, renewable and environmentally friendly resource. With a view to developing a new type of rubber composite based on starch, the objective of the study was to assess the factors affecting the reinforcing effect of starch and determine how reinforcement could be maximised In general, the study shows relatively poor reinforcement of natural rubber by starch, resulting in compounds of low stiffness and strength compared to compounds filled to a similar volume fraction with carbon black. The poor reinforcement is due to a weak interaction between polar starch and non-polar rubber and due to the large particle size of starch. However, the addition of polybutadiene maleic anhydride (PBMAH) and resorcinol formaldehyde (RF) coupling agents significantly improved the rubber to filler adhesion.
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REDAELLI, MATTEO. "POLYSILSESQUIOXANE AS ADVANCED “MOLECULAR” FILLER FOR RUBBER REINFORCEMENT." Doctoral thesis, Università degli Studi di Milano-Bicocca, 2017. http://hdl.handle.net/10281/153693.
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Il rinforzo di elastomeri mediante l’utilizzo di cariche (filler) inorganiche (nerofumo, SiO2) è ampiamente impiegato nell'industria dei pneumatici per ottenere e potenziare le proprietà meccaniche dei materiali. In particolare, recenti studi hanno dimostrato che il controllo della morfologia delle particelle di SiO2, la loro funzionalizzazione superficiale e la loro distribuzione all'interno della matrice polimerica (interazioni filler-filler e interazioni filler-gomma) svolgono un ruolo chiave per ottenere e migliorare le proprietà meccaniche. Questi risultati suggeriscono che l'utilizzo di filler con struttura e funzionalità controllabili, in grado di migliorare contemporaneamente le interazioni filler-filler e filler-gomma, possa essere un approccio promettente e innovativo per il miglioramento delle proprietà dei materiali compositi utilizzati nell’industria dei pneumatici. Tra i materiali presenti e studiati in letteratura, i PoliSilsesQuiossani (PSQs) sono una nuova classe di materiali ibridi organici-inorganici che presentano o conferiscono, se inclusi in polimeri, una serie di proprietà interessanti per una possibile applicazione industriale (ad esempio stabilità termica, proprietà meccaniche, ecc). Tuttavia, il controllo e l’effetto dell’introduzione dei PSQs nei polimeri è un fenomeno complesso e sono necessari ulteriori studi per stabilire le relazioni tra la struttura/morfologia e le proprietà impartite ai nanocompositi.
L'obiettivo di questo lavoro di dottorato è quindi quello di studiare e valutare l’utilizzo di PSQs con diverse strutture molecolari (cage o ladder) come filler innovativi in nanocompositi potenzialmente sfruttabili nelle formulazioni dei pneumatici.
In particolare, è stata messa a punto una nuova sintesi dove SiO2 e cage-PSQs (POSS) appartengono alla stessa struttura molecolare (SiO2@POSS). La sintesi prevede una silanizzazione della SiO2 mediante l’utilizzo di un silano e la successiva reazione con diverse quantità di OctaMethacrylPOSS in presenza di un attivatore radicalico (dicumilperossido), il quale permette l’attivazione dei gruppi reattivi del POSS e del silano. SiO2@POSS è stato poi utilizzato come filler in Stirene Butadiene per la preparazione di nanocompositi (SBR/SiO2@POSS).
Dopo aver verificato l’effettiva funzionalizzazione del POSS in SiO2@POSS mediante spettroscopia IR e NMR, le interazioni tra SiO2@POSS e il polimero sono state studiate mediante SEM, AFM e NMR. I risultati hanno mostrato un’elevata adesione all’interfaccia tra i due materiali, un aumento della rigidità delle catene polimeriche e una notevole copertura delle particelle di filler con strati di polimero confermando quindi un’elevata interazione filler-polimero nel materiale finale. Queste proprietà hanno notevoli conseguenze dal punto di vista meccanico migliorando significativamente il rinforzo del polimero, diminuendo la dissipazione di energia sotto sforzo, portando ad una potenziale riduzione del filler nel materiale finale.
Un approccio simile, è stata utilizzato per la preparazione di nanocompositi di Polibutadiene (PB) contententi PSQs a struttura mista (cage e ladder) funzionalizzati con gruppi tiolo (SH-NBBs) altamente reattivi. Le misure 1H NMR e di swelling hanno mostrato una forte correlazione tra la struttura e le interazioni polimero-filler (PB-NBBs) con conseguente diminuzione della mobilità delle catene polimeriche. Le misure dinamo meccaniche (DMTA) hanno confermato che piccole quantità di NBBs forniscono un notevole rinforzo e che il controllo della struttura degli NBB sembra essere fondamentale per le performance dei nanocompositi.
In conclusione, i risultati evidenziano un chiaro contributo della struttura dei PSQs nel favorire regioni di gomma legata che impartiscono particolare rinforzo ai nanocompositi. Ciò rappresenta un punto di grande rilievo poiché consente di esplicitare l’azione dei PSQs come filler molecolare innovativo.The reinforcement of elastomers (e.g. PolyButadiene PB, Styrene Butadiene Rubber SBR) by addition of inorganic fillers (carbon black, SiO2) is a practice widely employed in tire industry. In particular, the control SiO2 NPs morphology, surface functionalities, and their networking within the polymer matrix (i.e. filler-filler and filler-rubber interactions) plays a key role in achieving desired mechanical properties. These outcomes suggest that the utilization of fillers with tailorable structure and functionalities, able to simultaneously enhance the networking and the interaction with rubber, may be a promising strategy for upgrading the composites properties. Emerging fillers which seems to be suitable candidates are Polysilsesquioxanes (PSQs), a novel class of hybrid materials which exhibit or impart, if included in composites, a number of beneficial properties (e.g. thermal stability, mechanical properties, etc…). Stimulated by this background, the aim of this work is to explore the possibility to employ PSQs with different molecular structure (cage or ladder-like) as innovative fillers in rubber nanocomposites potentially exploitable in tires formulation. In detail, a novel hybrid filler, SiO2@POSS, where SiO2 and cage-like PSQs (POSS) belong to the same functional structure, has been developed by grafting on silanized SiO2 different loadings of OctaMethacrylPOSS, using a surface reaction mediated by dicumylperoxide. The hybrid filler was then employed for preparing SBR/SiO2@POSS nanocomposites, which display outstanding mechanical properties. This has been associated to the peculiar structure of SiO2@POSS, constituted by NPs aggregates partially interconnected and decorated by POSS nanounits which, thanks to the high number of reactive functionalities, promote the formation of a tight filler network which immobilizes filler and rubber, afford a relevant reinforcement and improve the hysteretical properties. A similar approach, has been applied for study the properties of PB nanocomposites including PSQs with tailorable cage or ladder-like structure. Swelling experiments and, more in depth, 1H NMR revealed a significant relation between NBBs architecture and their interactions with the polymer, resulting in restricted rubber chains mobility and significant reinforcement. In summary, the whole results suggest that PSQs can be promising fillers, which grant the transfer of the advanced properties of these nanounits to the final nanocomposites.
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Jampen, Stephan. "Rheological properties of gellan gels containing filler particles." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp03/MQ35899.pdf.
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Zhang, Hongquan, and 張宏泉. "Hydroxyapatite whiskers: preparation and useas resin-reinforcing filler." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2008. http://hub.hku.hk/bib/B41508920.
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Nitschke, Annika. "Investigation of Polymer-Filler Interactions Using Functionalized Nanoparticles." Doctoral thesis, Niedersächsische Staats- und Universitätsbibliothek Göttingen, 2020. http://hdl.handle.net/21.11130/00-1735-0000-0005-1363-6.
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Qian, Mengsha. "Reinforcement of Elastomers by Reactive Ionic Surfactant Filler." University of Akron / OhioLINK, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=akron1522424439025308.
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Nakamura, Michiko. "Processing of multiple filler-gap dependencies in Japanese." Thesis, University of Hawaii at Manoa, 2003. http://proquest.umi.com/pqdweb?index=0&did=764748181&SrchMode=1&sid=1&Fmt=2&VInst=PROD&VType=PQD&RQT=309&VName=PQD&TS=1233163310&clientId=23440.
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Solouki, Abbas <1986>. "Waste Mineral Filler Recycling in New Pavement Solutions." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2022. http://amsdottorato.unibo.it/10394/1/Solouki_Thesis.pdf.
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Società Azionaria Prodotti Asfaltico Bituminosi Affini (S.A.P.A.B.A. s.r.l.) is an asphalt/aggregate production plant located in Bologna, Italy. The resulting dirt and mud from the washing process is stored at specific sedimentation lakes close to the plant and are referred to as waste silt. The initiative and motivation of the current research follows the 12th objective of the sustainable development goals proposed by the United Nations. As a result, the overall aim of the current study was to reduce the impact of waste mineral fillers through recycling in new paving solutions. Considering three paving types of cement-bound, geopolymer-bound and asphalt pavements the following objectives were set: 1) To investigate the possibility of recycling waste silt in cement-bound paving solution; 2) To explore the feasibility of producing geopolymer-bound paving solutions containing waste silt; 3) To study the potential of using waste silt as fillers in different asphalt pavements. The first objective was achieved by utilizing waste silt into cement-bound materials. For this purpose, the by-product was introduced to cement mortars and was partially replaced (20%) with the natural sand. Moreover, statistical models were used to produce concrete paving blocks. The second objective was pursued by studying the feasibility of using the waste silt as a filler in geopolymer cement products. Following a comprehensive review, the silt was thermally calcined and used as filler in geopolymer cement and paving blocks. The third objective was achieved by evaluating the rheological and mechanical performance of hot mix, porous and semi-flexible asphalt containing waste silt. The limestone filler of a hot mix asphalt was replaced with thermally and untreated waste silt. To sum up, different paving blocks and asphalt pavements mixtures containing waste silt were proposed that presented acceptable performance when compared to different national and European standards.
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Cheuk, Ming Wai. "Study of composite material filler with different surface treatment /." access abstract and table of contents access full-text, 2004. http://libweb.cityu.edu.hk/cgi-bin/ezdb/dissert.pl?msc-ap-b21174106a.pdf.
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Thesis (M.Sc.)--City University of Hong Kong, 2004.At head of title: City University of Hong Kong, Department of Physics and Materials Science, Master of Science in materials engineering & nanotechnology dissertation. Title from title screen (viewed on Aug. 31, 2006) Includes bibliographical references.
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Farahani, Farnaz. "Comparison of Optical Methods for Fines and Filler Characterization." Thesis, KTH, Skolan för kemivetenskap (CHE), 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-216999.
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This thesis presents an evaluation study of three different image analysis instruments (FiberTester, FiberTester+ and ImageStream) and a laser diffraction (LD) instrument, for the analysis of the fine fraction of a stock. The instruments had different spatial resolutions and measurement ranges. Measurements were made on three different samples; pulp fines, paper filler (precipitated calcium carbonate) and the mix of them. Two comparisons were made; one with only data from image-based analysers, and one where LD data was also included. In the first comparison, the data was area-weighted, while in the second comparison, it was volume-weighted. To conduct a meaningful data comparison between the imaging and LD techniques, the multi-parameter imaging data was transformed to Equivalent Sphere Diameter. For the pulp fines sample, LD did not exhibit particles with Equivalent Sphere Diameter smaller than 6 μm and showed poor correlation with Image-based analysers. However, the LD results correlated better with Image-based methods for PCC particles. The ImageStream was the most capable instrument for detecting smallest particles among all the analysers. Among the image-based analysers, FT+ delivered the best results for relatively large particles.
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Feng, Xianzhong. "Enhanced barrier performance of cellulosic wood fiber/filler network." Thesis, University of British Columbia, 2016. http://hdl.handle.net/2429/58543.
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Cellulose is an abundant material, which is widely used in papermaking. It is both a biodegradable and sustainable material. However, its hydrophilic nature may limit its applications in specific and novel areas such as waterproof packaging and paper based microfluidics. In this thesis, three different routes are followed to render the surface of the paper superhydrophobic. First, chemical vapor-phase silanization is done on handsheets made from wood pulp with untreated kaolin clay and precipitated calcium carbonate (PCC) as fillers. The effect of fiber length, filler’s type, size, and concentration on the barrier performance of handsheets is shown. Secondly, mircofibrillated cellulose (MFC), which serves as reinforcement agent in paper, is employed as an additive to change the hydrophilic property of paper. MFC is silanized to obtain hydrophobicity before being dispersed into the pulp suspension. Then the resulting paper undergoes an additional silanization (post-treatment). The third approach involves depositing Janus clay particles on untreated paper. A Janus particle has a hydrophobic and a hydrophilic surface. Because clay particles are hydrophilic, they are treated to obtain hydrophobicity on one side, while the other side remains hydrophilic. An efficient method to obtain these types of particles is the formation of a Pickering emulsion. The study here, focuses on the determining the barrier properties of the prepared superhydrophobic or hydrophobic papers: wettability, water vapor transmission rate (WVTR), and air permeability. The handsheets with shorter fiber length, precipitated calcium carbonate, smaller filler size and lower filler content, were found to exhibit lower WVTR values. The water contact angle of handsheets loaded with fillers, Janus clay particles and hydrophobic MFC, was found to be 120~130°, 141° and 134~144° respectively.Applied Science, Faculty of
Chemical and Biological Engineering, Department of
Graduate
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Huang, Huan Yao, and barbar0324@gmail com. "The preparation and characterization of polypropylene-compatibilizer-filler composites." RMIT University. Applied Sciences, 2010. http://adt.lib.rmit.edu.au/adt/public/adt-VIT20100218.101808.
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Polypropylene (PP) composites includ a mineral filler, though they can be enhanced by blending with an elastomer. Blending rigid fillers with PP increased strength while decreasing toughness. Blending soft elastomers with PP decreased strength while increasing toughness. PP-elastomer-filler ternary composites offer synergism because the increase of strength due to filler may compensate the loss of strength due to the elastomer. Two morphologies were identified, separated elastomer and filler particles in PP, and filler particles encapsulated by elastomer in PP. Interaction between filler and PP matrix are proposed to increase with the addition of polar elastomers when encapsulated morphology is formed, leading to enhanced mechanical properties. PP-elastomer-filler blended tapes were prepared via single-screw extrusion. Annealing was performed after cooling the tapes, and this combination proved to increase the modulus. Characterization of the composites was carri ed out using thermogravimetry, dynamic-force thermomechanometry, modulated-force thermomechanometry, and Fourier transform infrared imaging. Incorporation of polysiloxane elastomer increased the mobility of PP during extrusion. Elongation at break increased with increasing polysiloxane content, while the tensile modulus was slightly decreased. The silica core within the polysiloxane particles provided an additional strength enhancement. Polar elastomers aided binding between PP and fillers, while enhancing strength and toughness. Glass transition temperature and segmental motion activation energy was shifted to higher temperature with addition of elastomer and filler, including kaolin and talc.
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Darsell, Jens Tommy. "High temperature Ag-Pd-CuOx air braze filler metal." Online access for everyone, 2007. http://www.dissertations.wsu.edu/Dissertations/Spring2007/J_Darsell_042607.pdf.
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Ogden, Gary N. "The quality of binder-filler interfaces in carbon electrodes." Thesis, Loughborough University, 1995. https://dspace.lboro.ac.uk/2134/7049.
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The aims of this research project were to identify and classify the binder-filler interfaces formed in carbon electrodes and to determine the effects of the interfacial quality on important electrode properties. The effects of raw materials and some fabrication process variables on interfacial characteristics and quality of laboratory produced test electrodes were also studied, and the development of binder-filler interfaces during the carbonisation process followed. Electrode quality was assessed by measurement of density, electrical resistivity and tensile strength. Pore structural data were also obtained by using a computerised image analysis system allied to an optical microscope. Interface quality data were obtained by examining etched surfaces in a scanning electron microscope and classifying the binder-filler interface observed into one of five categories. The category depending on the extent of contact between the binder and filler. Accordingly, test electrodes were produced from combinations of four filler carbons, comprising three grades of calcined petroleum coke and an electro-calcined anthracite, and four coal-tar binder pitches which varied in the type and quantity of insoluble matter content. Examination of these test electrodes showed that the nature of the filler carbon used had a dominant influence on the quality of the interface formed, as assessed by this technique. A combination of one filler carbon and one binder pitch was used to study the effects of some fabrication process variables. These were pitch content and, mixing time and temperature. Of these process variables, pitch content and mixing temperature were found to have the major effects on the binder-filler interface and electrode quality. Investigation of the development of the binder-filler interfaces during the carbonisation process showed three distinct zones of interface development and transformation. These zones were associated with three temperature dependent mechanisms; thermal stress relaxation between 200-350 degrees C, volatile gas evolution from coal-tar pitch decompositionb etween3 50-600 degrees C and stresses induced by thermal contraction of the binder phase between 600-1000 degrees C.
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Li, Yalan. "The development of sub-micro filler enhanced polymer composites." Thesis, Nottingham Trent University, 2007. http://irep.ntu.ac.uk/id/eprint/192/.
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Sub-micro silica flakes and graphite reinforced polymer composites have been developed in this research. The sub-micro polymer composites are designed to overcome problems associated with nanocomposite technology. Apart from the high cost of production, the other major problem in nanocomposites is reduced efficiency in mechanical reinforcement at high filler loadings. The surface area of nano-fillers in high filler loaded composites is too high resulting in insufficient polymer molecules to wet the filler surface and hence increased filler agglomeration occurs. Increasing filler dimension into the sub-micro range can avoid such difficulties. The dimension of fillers in the sub-micro range also has the advantage of utilising modern polymer processing technologies. In this thesis, sub-micro composite reinforcement has been studied through the identification of suitable fillers, modelling of sub-micro composites and experimental validation of model predictions. The processing methodology, effects of filler loading, aspect ratio and compatibility of filler with matrix are also investigated. In addition, rheology, crystallisation, fracture toughness and the thermodynamic behaviour of submicro filler reinforced polymer composites are studied. The investigation was primarily focused on various combinations of single-layered silica flakes and multi-layered graphite sheets reinforced nylon-6 and polypropylene. The predicted Young's modulus and strengths of developed composites are as high as 3.3 GPa and 81 MPa at 5wt% silica flake content as well as 11.75 GPa and 301MPa at 30wt% flake fraction, respectively. Experimental results show that tensile modulus and strengths of the submicro composites produced agree well with modelling data at low filler loading. They are, however, much lower than the predictions in the high filler loading range due to the breakage of silica flakes during composite processing. In spite of filler breakage, the tensile modulus and strength of 5wt% silica flake reinforced N6 improved 68% and 67% respectively, compared to the N6. The tensile strength is also 38% higher than thatof 5wt% clay/N6 nanocomposites. The tensile modulus of 30wt% silica flake reinforced N6 improved over 240% which is similar to the achievement of 30wt% glass fibre/N6 composites. In addition, the fracture toughness and thermal deflection temperature of a silica flake/N6 composite improved by 17% at 5wt% and 20.3 oC at 10wt% filler content respectively. For multi-layered graphite sheet reinforced polypropylene sub-micro composites, mechanical properties are a function of both filler thickness and filler loading. Over 112% improvement in Young's modulus has been achieved with a composite produced via a multi-extrusion method at 20wt% filler loading, compared with the pure polymer. The crystallinities of all sub-micro composites produced are either similar to or lower than those of pure polymers. This implies that the major contribution to the improvement of mechanical properties is from sub-micro fillers. In addition, the crystallisation rate and crystallisation temperature of sub-micro composites are increased when compared with base polymers due to the nucleation effect of fillers. The introduction of sub-micro fillers into nylon-6 and polypropylene did not result in significant change in rheology. This may be associated with flake breakage and relatively poor interfacial bonding at the filler/polymer interface. In summary, this work demonstrates the potential of sub-micro filler enhanced composites in improving major engineering properties. It also proves that the sub-micro approach can fill the gap between nano and fibre reinforcement.
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Nordstedt, Tobias. "Conceptual Development of an Automated Corrugated Cardboard Box Filler." Thesis, Uppsala universitet, Industriell teknik, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-354431.
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The project aimed at conceptually develop a solution that is able to automatically transfer an already stacked and measured heap of goods from an order tote into an erected corrugated cardboard box, whereas the dimensions of the corrugated cardboard box and the stack are allowed to vary within a specified interval. The method for this project consisted of five main parts: feasibility study; concept generation; concept choice; design; and evaluation. The project was initiated by a feasibility study where the problem was clarified and knowledge regarding the problem was gathered. The feasibility study resulted in an user requirement specification and a product requirement specification. The product requirement specification was utilized in the evaluation processof the final developed concept. The concept generation was conducted according to structured methods prescribed by Ulrich and Eppinger. The concept choice was done by the use of Pughs concept choice matrix. The result of this project consists of a conceptual proposal of how the previously described problem may be solved. The final developed concept resulted in a cad model. The evaluation showed that the concept did not fulfill the product requirement specification, despite this it is assessed that the concept in its working principle has good merits that are worth further investigation. Further development of the concept remain and validation of the working principle is needed. Further choices concerning form, material, and components remain. The report contributes to a foundation for further development of an automated filling mechanism for erected corrugated cardboard boxes.
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LI, Jr-Hung. "INFRARED BRAZING OF LOW CARBON SPEED WITH COPPER FILLER." University of Cincinnati / OhioLINK, 2001. http://rave.ohiolink.edu/etdc/view?acc_num=ucin990736063.
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Zhang, Hongquan. "Hydroxyapatite whiskers preparation and use as resin-reinforcing filler /." Click to view the E-thesis via HKUTO, 2008. http://sunzi.lib.hku.hk/hkuto/record/B41508920.
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MIRIZZI, LORENZO. "Novel filler to enhance thermal condcutivity of rubber nanocomposites." Doctoral thesis, Università degli Studi di Milano-Bicocca, 2023. https://hdl.handle.net/10281/403915.
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I nanocompositi di gomma mostrano generalmente una scarsa conduttività termica, che può essere parzialmente migliorata dall'aggiunta di riempitivi termicamente conduttivi, ad esempio grafite, nerofumo, fibre di carbonio, particelle di ceramica o di metallo. Per raggiungere questo obiettivo sono in genere necessari concentrazioni di riempimento elevate; tuttavia, ciò altera notevolmente il comportamento meccanico e la densità di reticolazione dei materiali finali. Inoltre, i sistemi di riempimento attualmente impiegati non sono in grado di soddisfare contemporaneamente i requisiti chiave di elevata conducibilità termica e prestazioni meccaniche. In questo contesto, l'attività di ricerca del dottorato mira a progettare nuovi riempitivi adatti allo sviluppo di nanocompositi di gomma con elevata conducibilità termica e prestazioni meccaniche soddisfacenti. Sarà condotta un'indagine su diversi nano-riempitivi termicamente conduttivi, studiando in profondità le correlazioni tra struttura, morfologia, dispersione e distribuzione delle nanoparticelle nella matrice polimerica e proprietà finali dei compositi. Le migliori formulazioni verranno selezionate ed eventualmente scalate al fine di fornire reali applicazioni tecnologiche.Rubber nanocomposites generally exhibit poor thermal conductivity, which has been partially enhanced by the addition of thermally conductive fillers, i.e. graphite, carbon black, carbon fibres, ceramic or metal particles. High filler loadings are typically necessary to achieve this target; however, this dramatically alters the mechanical behaviour and the cross-linking density of the final materials. Further, the filler systems currently employed are not able to fulfil the key requirements of high thermal conductivity and remarkable performances, simultaneously. In this context, the PhD research activity aims at design novel fillers suitable for developing rubber nanocomposites with high thermal conductivity and satisfactory mechanical performances. A survey of different conductive nanofillers will be carried out, by investigating in depth the correlations between nanoparticles structure, morphology, dispersion and distribution in the polymer matrix, and final composites properties. The best formulations will be selected and possibly up-scaled in order to provide real technological applications.
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Erguney, Fatih M. "COARSE-GRAINED MC SIMULATIONS OF POLYMER NANOCOMPOSITES." University of Akron / OhioLINK, 2007. http://rave.ohiolink.edu/etdc/view?acc_num=akron1176404164.
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Sousa, Joao Jose Martins Simoes de. "The influence of formulation on the formation of and drug release from film coated pellets." Thesis, University College London (University of London), 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.388207.
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Lu, Chen Pelton Robert H. "Mechanisms of filler flocculation with PEO/cofactor dual-component flocculants /." *McMaster only, 2003.
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Gursky, Barry Michael. "Particle size distribution optimization of filler content in shingle asphalt." Thesis, Georgia Institute of Technology, 1986. http://hdl.handle.net/1853/20989.
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Mijangos-Santiago, Faustino. "Effect of particulate filler on molecular orientation in molten polyethylene." Thesis, McGill University, 1989. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=74236.
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This research involves the study of the effects of the presence of a calcium carbonate filler, with particle sizes smaller than 1 $ mu$m, in the matrix of a medium density polyethylene on: (a) extrudate swell, (b) the relaxation expectrum, and (c) mechanical properties such as the Young's modulus and the yield strength.It was found that: (a) the Young's modulus and the yield strength are improved most when untreated filler particles are used, (b) the relaxation spectrum is shifted the most to longer times when untreated filler particles are used, and (c) extrudate swell is reduced by the presence of filler particles, due to some sort of interaction between them and the polymer molecules, and not by a simple substitution of polymer molecules by filler particles.
Filled polymers were used to produce tubular extrudates in an attempt to use the long relaxation times to delay swell and thus maintain the anisotropy generated by flow through a die having an expanding channel. It was found that the storage modulus of samples taken along the hoop direction was not different from that of samples taken along the axial direction. This lack of anisotropy was attributed to the low shear rate in the die and to competition between extensional flow that tends to orient polymer molecules in the hoop direction and shear flow that tends to orient polymer molecules in the axial direction. It is concluded that it is not possible to obtain significant differences in the loss modulus between the axial and hoop directions, i.e., measurable anisotropy, unless one of these processes becomes predominant.
The last part of the research involved a study of the role of uniaxial extension in promoting orientation. Molten strips were stretched at different strain rates, and it was found that molecular orientation in the stretching direction levels off at a particular strain rate. The maximum orientation depends on the treatment of the filler particles and on the additives used. This finding points to the possibility of using the total energy used to deform the molten strips as a criterion for obtaining the maximum molecular orientation in the direction of stretching.
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Bream, Charles Ellett. "Recycling of thermoset composites as a reinforcing filler in thermoplastics." Thesis, Brunel University, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.299099.
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Ccori, Telma Aparecida Félix da Matta. "A prosódia do filler este da língua espanhola: leituras pragmáticas." Universidade de São Paulo, 2018. http://www.teses.usp.br/teses/disponiveis/8/8142/tde-11022019-153550/.
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A palavra morfofonológica este da língua espanhola é submetida a análise acústica no presente trabalho com o objetivo de verificar-se padrões prosódicos para seus diferentes usos: referencial (adjetivo/pronome) e metadiscursivo. Os valores dos parâmetros acústicos mensurados para a ocorrência de este referencial são comparados aos das ocorrências de este metadiscursivo com a finalidade de reconhecer-se uma subcategorização do uso metadiscursivo: filler e marcador discursivo. São utilizados dados de fala espontânea do espanhol do México, coletados no website YouTube. Verificamos que, do ponto de vista prosódico, as tendências de comportamento de este referencial metadiscursivo apresentam divergências ou convergências a depender da interpretação pragmática relacionada ao último uso.The word este of Spanish is acoustically analyzed in the present work in order to verify prosodic patterns for its different uses: referential (adjective / pronoun) and metadiscoursive. The measured values of acoustic parameters for each type of occurrence are compared with the purpose of proposing two different classes inside metadiscoursive use: a filler and a discourse marker. We use spontaneous speech data from Mexican Spanish, collected on the YouTube website.From the prosodic point of view, the behavioral tendencies of metadiscursive and referential este have divergences or convergences depending on the pragmatic interpretation related to the last use.
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Soltan, Omar. "Polypropylene/filler nanocomposites by melt compounding and in situ polymerization." Thesis, Stellenbosch : University of Stellenbosch, 2010. http://hdl.handle.net/10019.1/5310.
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Thesis (PhD (Chemistry and Polymer Science))--University of Stellenbosch, 2010.ENGLISH ABSTRACT: The properties of polymer nanocomposites depend greatly on the chemistry of the polymer matrices, the nature of the nanofillers, and the way in which they are prepared. Understanding the synthesis–structure–property relationship of nanocomposites is vital for the development of advanced polymer nanocomposites with enhanced mechanical strength, stiffness and toughness for structural engineering applications. To this end, the primary aim of this study was to determine the impact that the preparation methods have on the properties of PP/filler nanocomposites, with specific focus on the in situ polymerization of propylene via the methylaluminoxane (MAO) activated metallocene catalyst technique. Two different fillers (Silica and Calcium carbonate) were used as support for the metallocene catalysts. Different supporting methodologies for the synthesis of the supported catalyst were examined. A C2 symmetric metallocene catalyst ansa dimethylsilylbis(2-methyl benzoindenyl) zirconium dichloride (MBI) was used in this study. The catalyst systems were then evaluated for propylene polymerization. The early observation shows that a direct adsorption of the metallocene onto the filler has a diminishing effect on the catalyst productivity and the fillers had to be treated with MAO in order to avoid catalyst deactivation by the filler surface. Due to the low productivity of the supported active species, the presence of soluble catalyst active species, besides the supported active species is required in the synthesis of PP nanocomposites via in situ polymerizations. The syntheses of PP nanocomposites were carried out via in situ polymerization in which different quantities of MAO treated fillers were reacted with pre-activated catalyst solution. The effect of the addition of MAO-filler on the polymerization kinetics and consequently on PP matrix microstructure was investigated. Changes in the in situ polymerization kinetics, compared to kinetics of homogeneous polymerization, were observed. Therefore, the microstructure of the polymer matrix was also influenced by the presence of nanofillers in the polymerization media. The influence of the different synthesis methods on the performance of the nanocomposites was investigated using melt-mixed PP/filler nanocomposites obtained using PP homopolymer. The dispersed phase morphologies of the different nanocomposites were investigated by transmission electron microscopy (TEM). Results show that PP nanocomposites with improved filler dispersion were achieved by in situ polymerization compared to melt-mixed nanocomposites. The influence of the synthesis method on the crystallization behaviour of PP nanocomposites was also investigated. It was found that, for the in situ prepared nanocomposites the tacticity of the PP matrix plays the major role in determining the degree of crystallinity. Results also show that when nanocomposites with comparable PP matrices are compared, the overall crystallization rate of the in situ polymerized nanocomposites is higher than that of the melt mixed nanocomposites. The mechanical properties of in situ polymerized PP and melt mixed PP nanocomposite were also investigated and compared. Due to improved nanoparticle dispersion in the PP matrix, in situ polymerized nanocomposites show enhanced mechanical properties, especially tensile and impact properties, compared to pure PP and melt mixed prepared nanocomposites when a PP matrix of equivalent microstructure was used. Finally, the melt compounding method was further investigated using different fillers and commercial PP as a matrix. The effect of filler type, size and applied surface coating on the flow and mechanical properties of PP nanocomposites was studied. The aim of this part of this study is to obtain a good trade-off between the processability and the mechanical properties and to gain insight into the cause of the emergence of different properties for nanocomposites prepared by melt compounding.
AFRIKAANSE OPSOMMING: Die eienskappe van polimeer nanokomposiete hang grotendeels af van die chemie van die polimeer matriks, die wese van die nano-vullers, en die manier waarop hierdie materiale berei word. Om die sintese-struktuureienskap verwantskap te verstaan is noodsaaklik vir die ontwikkeling van gevorderde nanokomposiete met beter meganiese eienskappe, styfheid en taaiheid vir strukturele ingenieurstoepassings Die primêre doelstelling van hierdie studie was dus om die impak van voorbereidingsmetodes op die eienskappe van PP/vuller nanokomposiete te bestudeer, met spesifieke fokus op die in-situ polimerisasie van propileen met metiel alumoksaan-geativeerde metalloseen kataliste. Twee verskillende vullers (silika en kalsium karbonaat) is gebruik as ondersteuning vir die metalloseen kataliste. Verskillende metodiek is gebruik om die ondersteunde kataliste te berei. ‘n C2 simmetriese metalloseen katalis ansa-dimetielsiliel(2-metiel bensoindeniel) sirkonium dichloride (MBI) is in die studie gebruik. Die katalissisteme is daarna evalueer vir propileen polimerisasie. Daar is oorspronklik vasgestel dat direkte adsorpsie van die metalloseen op die vuller ‘n negatiewe effek op die katalis aktiwiteit gehad het, en dat die vuller oppervlak eers met MAO behandel moes word om deaktivering van die katalis deur die vuller-oppervlak te vermy. As gevolg van die lae aktiwiteit van die ondersteunde aktiwe katalisspesies, is die teenwoordigheid van opgeloste aktiewe katalis nodig vir die voorbereiding van PP nanokomposiete via in situ polimerisasie-reaksies. Die sintese van PP nanokomposiete is uitgevoer deur in –situ polimersiasie waartydens verskillende hoeveelhede MAO-behandelde vullers gereageer is met vooraf-geaktiveerde katalis oplossings. Die effek van die byvoeging van MAO-vuller op die polimerisasie-kinetika en gevolglik op die PP matriks mikrostruktuur is ondersoek. Dit is gevind dat die mikrostruktuur van die polimeer-matriks beinvloed word deur die teenwoordigheid van nanovullers in die polimerisasie-medium. Die invloed van verskillende bereidingsmetodes op die eienskappe van die nanokomposiete is ondersoek deur smelt-vermengde PP/vuller nanokomposiete te maak. Die dispersie-fase morfologie van verskillende nanokomposiete is ondersoek deur transmissie elektron mikroskopie (TEM). Resultate wys dat PP nanokomposiete met verbeterde vuller-dispersie berkry is deur in situ polimerisasie in vergelyking met die smelt-vermengde materiale. Die effek van die sintese-metode op die kristallisasie van die PP nanokomposiete is ook ondersoek. Daar is gevind dat, vir die in situ bereide nanokomposiete, die taktisiteit van die PP matriks die grootste rol speel in die bepaling van die persentasie kristalliniteit. Resultate het ook gewys dat, wanneer nanokomposiete met soortgelyke PP matrikse vergelyk word met die in situ nanokomposiete, die laasgenoemde se tempo van kristallisasie hoer is as vir die smelt-vermengde nanokomposiete. Die meganiese eienskappe van die in situ bereide en smelt-vermengde PP nanokomposiete is ook ondersoek en vergelyk. As gevolg van verbeterde nano-partikel dispersie in die PP matriks, het die in situ bereide nanokomposiete beter meganiese eienskappe openbaar, in vergelyking met die smelt-vermenge nanokomposiete, veral trek- en slagsterkte. . Laastens is die smelt-vermengings metode verder ondersoek deur gebruik te maak van verskillende vullers en kommersiële PP as matriks. Die effek van die tipe vuller, die grootte en die oppervlakbedekking van die vullerpartikels op die vloei en meganiese eienskappe van die PP nanokomposiete is ondersoek. Die doel van hierdie studie was om ‘n balans te kry tussen prosesseerbaarheid en meganiese eienskappe en om insig te verkry oor die verskille in eienskappe wat openbaar word wanneer smeltvermengde nanokomposiete bereie word.
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Luskin, Timothy Clark. "Investigation of Weldability in High-Cr Ni-base Filler Metals." The Ohio State University, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=osu1366210427.
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Orr, Michael Romanoff. "Solidification Cracking Performance and Metallurgical Analysis of Filler Metal 82." The Ohio State University, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=osu1470067177.
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Phillips, Lakin N. "Evaluation of Ohio Coal as Filler Material for Thermoplastic Composites." Ohio University / OhioLINK, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1512564409202248.
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Chen, Kun. "INVESTIGATION OF GRAPHENE-BASED MULTI-FILLER ELECTRICALLY CONDUCTIVE ADHESIVE MATERIAL." University of Akron / OhioLINK, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=akron1555091658254182.
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Al-Salloum, Mohammed Y. "Use of Pyrolyzed Soybean Hulls as Filler in Polyamide-6." University of Akron / OhioLINK, 2021. http://rave.ohiolink.edu/etdc/view?acc_num=akron1626793395861062.
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Nitschke, Annika [Verfasser]. "Investigation of Polymer-Filler Interactions Using Functionalized Nanoparticles / Annika Nitschke." Göttingen : Niedersächsische Staats- und Universitätsbibliothek Göttingen, 2020. http://d-nb.info/1217481435/34.
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Mahmood, Salih Qasim. "Behavior of Lap Shear Connections with Thermally Insulating Filler Plates." PDXScholar, 2017. https://pdxscholar.library.pdx.edu/open_access_etds/4159.
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This research consists of experimental load tests and numerical simulations of structural steel connections with various filler materials to study the effect of non-steel fillers on the connection strength. Non-steel fillers are used in the steel connections to provide thermal insulation by reducing thermal bridging. Eight specimens having steel and polypropylene filler plates of various thicknesses were tested in the laboratory. The collected data were compared to a Finite Element Analysis (FEA) using ABAQUS to validate the numerical results. After validation, three parametric studies were conducted using ABAQUS to provide insight into general behavior of connections with a variety of fillers that could be used as thermal breaks. In addition, an extreme case of having air gaps instead of alternative fillers was also considered.
The Research Council on Structural Connections (RCSC 2014) suggests a reduction in the bolt shear strength when undeveloped fillers with a thickness of more than 0.25 inch are used while using any non-steel material is prohibited due the limited research available.
Most research studies have investigated the mechanical behavior of thermal breaks in either end-plate moment connections or slip-critical connections. No data is available for thermal breaks in bearing-type connections up to failure.
This research aims to study the effects of filler material properties such as modulus of elasticity and strength on bolt strength, as well as investigate whether the current equation in RCSC 2014 is applicable for alternative filler materials like polypropylene that has less than 0.5% of the steel modulus of elasticity and less than 10% of steel strength.
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GIOFFREDI, EMILIA. "Polymer Crystallization: Micro- and Nano- Filler Effects on Isotactic Polypropylene." Doctoral thesis, Politecnico di Torino, 2012. http://hdl.handle.net/11583/2500104.
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Isotactic polypropylene (iPP) is one of the commodities used in the largest quantity today. Its good mechanical properties and relatively low price result in continuous growth of pro-duction and expansion of its market. The continuously increasing application accelerates research on all related fields, including the preparation of iPP-based composites and blends.
The preparation of polymer blends is an important technique in order to modify the target property of an individual polymer according to the requirement of the application field. Since the features of semi-crystalline polymers depend on the crystallinity degree and crystallite morphology, studies about the effects of fillers on the crystallization behavior of composites are of great interest.
Nucleated crystallization has been the subject of several studies over the last 50 years or so [Cormia et al. 1962, Binsbergen 1970, Mercier 1990].
In the relative simple case of isothermal crystallization, the presence of a nucleating agent (NA) shortens the induction time as well as enhances the overall rate of transformation from the molten state to the crystalline solid state. A shortening of the induction time due to a NA is obviously understandable since the polymer melt does not have to form its own seeds to initiate crystallization (self-nucleation being a time-dependent phenomenon as it results from the statistical fluctuations in the local order). In the processing of polypropylene, a nucleating agent is usually used for reducing the size of the iPP spherulites, improving the optical clarity, decreasing the cycle time of the process and enhancing the mechanical properties.
Therefore, the main goal of this work is the investigation of the effects of different mi-cro- and nano- fillers on the isotactic polypropylene crystallization behavior, both in quies-cent and in flow-induced conditions.
To this aim, two types of isotactic polypropylene were mixed with maleic anhydride grafted polypropylene (PP-MA) as compatibilizer and various micro- (talc, carbon fibres) and nano- (montmorillonites, carbon nanofibres and carbon nanotubes) fillers were added. In order to keep the same matrix, the micro- and nano- composites were prepared by in-creasing the filler loading at a fixed iPP/PP-MA ratio (13.2).
Structural characterization was carried out by means of X-ray diffraction (XRD) and scanning electron microscopy (SEM) analyses and the materials behavior in the molten state was studied by means of rheological measurements in small-amplitude oscillatory shear (SAOS) with a rotational rheometer (plate-plate configuration).
Differential Scanning Calorimetry (DSC) was employed to investigate the crystallization in quiescent conditions of the prepared micro- and nano- composites. Both the quiescent and flow-induced crystallization were evaluated using SAOS techniques (dynamic time sweep tests).
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Hutley, T. J. "Structure-property relationships mineral-filled thermoplastics." Thesis, Cranfield University, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.380475.
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Gibbon, Luke Ryan. "Effects of Green Reinforcement Strategies on Mechanical Properties of High Volume Polymers." Thesis, North Dakota State University, 2013. https://hdl.handle.net/10365/26664.
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Green reinforcement in polymer systems have shown great promise in reducing cost, negative environmental effects, and dependency on nonrenewable resources. Both natural fillers and composite regrind can increase mechanical performance, while reducing new resin inputs for polymer based components. PVC and Polyurethane foam are widely used in North America in high volumes. Ground corn cob greatly increased the modulus of a flexible PVC system while minimally reducing maximum strength. The corn cob also showed signs of being a suitable filler in a polyurethane foam composite panel at low concentrations with minimal changes in mechanical performance. Polyurethane composite regrind illustrated great potential being used in new polyurethane composite panels with acceptable material properties. Replacing just a few percent of polyurethane and PVC with green reinforcement could reduce new production of these polymers by millions of pounds per year in North America alone.
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Motiee, Sima. "Effect of chemical additives on Z-direction filler distribution in paper." Thesis, University of British Columbia, 2013. http://hdl.handle.net/2429/44198.
Full textAbstract:
It is well known that paper properties such as opacity, printing quality, brightness, and roughness are affected by the z-direction mineral filler distribution. In this study, the effect of four different parameters (filler, starch, chemical retention aids and the machine parameter (vacuum)), on the z-direction filler distribution in paper samples was investigated.
Paper samples were made using an apparatus that simulates a suction box. Different levels of filler (PCC), chemical additives and vacuum were chosen based on a central composite design. The effect of these parameters on filler distribution in cross-section of paper samples was investigated by using Scanning Electron Microscopy (SEM) and Energy Dispersive X-ray analysis (EDX) which is a non-destructive technique. The area covering the thickness of the paper was divided into five layers and each layer was subjected to EDX analysis to obtain the calcium content through the paper thickness.
The results indicated that the filler distribution in the z-direction of paper samples increased from the top side to the wire side. The calcium content in the layer near the wire side was significantly higher than in the other layers. The other layers had similar calcium content. The chemical additives as well as vacuum in suction box had a significant effect on the filler distribution. Increasing the filler and starch led to higher level of filler content in all layers through the sheet thickness. Increasing the vacuum and retention aids led to higher level of filler content in layers near the wire side. The effect of high charge density starch used in our study was significantly higher than the effect of retention aids in retaining the filler through the thickness of the paper. Based on the obtained data, a set of empirical models were constructed that can predict the filler distribution through the thickness of the paper.
We validated our results by measuring the calcium content through applying image processing technique on the SEM cross-section images and measuring the ash content of paper samples. The results of both of these approaches confirmed the EDX measurements.
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Vanerek, Alois. "Filler retention in papermaking by polymeric and microparticulate retention aid systems." Thesis, McGill University, 2004. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=85655.
Full textAbstract:
Mineral pigments are added to paper with the aim of improving its optical and printing properties. The colloidal behavior of calcium carbonate filler shows a dependence on the quality of water used in suspensions, presence of dissolved and colloidal substances and type of polymer used as a retention aid. The role of the retention aids is to attach colloidal particles, such as fines and mineral pigments, to pulp fibers before or during the paper is made. Two very different single-component retention aids were utilized in calcium carbonate fillers destabilization and deposition on fibers. Cationic polyethylenimine destabilized or facilitated deposition of the filler on fibers by a charge neutralization mechanism while cationic polyacrylamide flocculated or deposited the filler on fibers via a bridging mechanism.In the presence of anionic dissolved and colloidal substances, the amount of cationic polyacrylamide had to be increased in order to achieve the same degree of pigment flocculation. The reason for the increase was due to the fact that the cationic polyacrylamide formed a polyelectrolyte complex with the anionic substances, namely sulfonated kraft lignin. The reaction between cationic polyacrylamide and lignin was found to be nearly stoichiometric. Low molecular weight cationic polyacrylamide formed mostly colloidal complexes while high molecular weight cationic polyacrylamide formed predominantly coacervate complexes; this was mainly due to differences in characteristic times of lignin association with the cationic polyacrylamide, clustering of polyacrylamide molecules and reconformation of polymer chains.
The performance of two-component retention aid systems consisting of a cationic polyacrylamide and anionic microparticles were evaluated by deposition of calcium carbonate filler on pulp fibers. Kaolin clay and bentonite were used to heteroflocculate polyacrylamide-covered surfaces of the fibers and pigment. Due to their inability to delaminate, kaolin clay and acid-treated montmorillonite showed no effect of calcium carbonate filler deposition. After cation exchange with sodium-rich solutions, which caused the montmorillonite to delaminate, the montmorillonite flocculation efficiency considerably improved. Kaolin clay neither delaminated after the cation exchange nor improved calcium carbonate deposition. Bentonite was found to completely delaminate when using polyacrylamide-treated fibers. When added to a suspension of fibers, filler and cationic polyacrylamide, bentonite was found to be in a form of stacks containing on average four platelets.
An alternative way to paper filling with pigment was tested on stationary sheets and on slow and fast Fourdrinier pilot paper machines. Using a secondary headbox on the pilot paper machines, a high degree of loading (above 30%) could be achieved using positive clay or calcium carbonate fillers. However, the fillers lowered the paper strength as they interfered with the fiber-fiber bonding in a similar fashion found in conventionally filled papers.
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Koukos, Christos [Verfasser], Sebastian [Akademischer Betreuer] Gehrmann, and Timm [Akademischer Betreuer] Filler. "Bewegungsanalyse der Fingergrundgelenke / Christos Koukos. Betreuer: Sebastian Gehrmann. Gutachter: Timm Filler." Düsseldorf : Universitäts- und Landesbibliothek der Heinrich-Heine-Universität Düsseldorf, 2016. http://d-nb.info/1081487720/34.
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