Dissertations / Theses on the topic 'Styrene butadiene rubber compound'

Thesis (M. Phil.)--Hong Kong University of Science and Technology, 2002.
Includes bibliographical references (leaves 93-100). Also available in electronic version. Access restricted to campus users.

Research was initiated to examine the feasibility of removing the majority of 4-PCH from the XSBR latex employed in carpet manufacturing. The reduction of 4-PCH from such latices would lend insight into the control of certain carpet related illnesses.

Typical rubber compounds used to manufacture industrial products such as tyres, hoses, conveyor belts, acoustics, shock pads, and engine mountings contain up to eight classes of chemical additives· including curing agents, accelerators, activators, processing aids, and antidegradants. The cure systems in these articles often consists of primary and secondary accelerators, primary and secondary activators, and elemental sulphur. Recent legislation impacting upon the working environment, safety and health has imposed a considerable burden on the manufacturers of rubber compounds to meet various obligations. The selection of raw materials and manufacturing processes that do not harm the environment is of great importance. A novel technique for preparing rubber formulations using crosslinking nanofillers such as silanised precipitated silica has been developed in this research. The silica surfaces were pre-treated with bis[3-triethoxysilylpropyl-] tetrasulphane coupling agent (TESPT).· TESPT is a sulphur containing bifunctional organosilane which chemically adheres silica to rubber and also prevents silica from interfering with the reaction mechanism of sulphur-cure systems. The tetrasulphane groups of the TESPT are rubber reactive and react in the presence of accelerator at elevated temperatures, i.e.140 -260°C, with or without elemental sulphur being present, to form crossIinks in rubbers containing chemically active double bonds for example styrene-butadiene rubber (SBR) and polybutadiene rubber (BR) .. SBR and BR rubber compounds containing 60 phr of TESPT pre-treated silica nanofiller were prepared. The silica particles were fully dispersed in the rubber, which was cured primarily by using sulphur in TESPT. The reaction between the tetrasulphane groups of TESPT and the rubbers was optimised by incorporating different accelerators and activators in the rubber. The mechanical properties of the rubber vulcanisates such as hardness, tear strength, tensile strength, elongation at break, stored' energy density at break, abrasion resistance, modulus and cyclic fatigue life were increased significantly when the treated silica filler was added. The need for the accelerator and activator was dependent on the composition of the rubber. Interestingly, the rubbers were fully cured without the use of elemental sulphur, secondary accelerator and secondary activator. As a result, a substantial reduction in the use of the curing chemicals was achieved without compromising the important properties of rubber compounds which are essential for maintaining long life and good performance of industrial rubber products in service. This approach has also helped to improve health and safety within the workplace and minimise harm to the enviromnent.Furthermore, a significant cost saving was achieved after reducing the number of curing chemicals in the rubber.

The effects of cure time, cure temperature, and air circulation on the release of 4-phenylcyclohexene (4-PCH) in tufted carpet backed with carboxylated styrene-butadiene rubber (SBR) latex were examined in this research project. 4-PCH is a suspect cause of certain "building-related" illnesses such as headache, upper respiratory and eye irritation, and fatigue. A standardized method for preparing carpet backed with SBR latex and analyzing its 4-PCH content was developed. The cure parameters investigated included three cure temperatures (225, 250 and 275°F), six cure times (0, 5, 10, 20, 40 and 60 minutes), and three air circulation rates (zero, three air exchanges per minute, and ten air exchanges per minute with 1500 linear feet per minute airflow). Increased airflow (1500 linear feet per minute) over the carpet surface produced the greatest impact on 4-PCH release from carpet. Increasing the cure temperature and cure time also significantly increased the release of 4-PCH.

Thesis (M.S.)--University of Akron, Dept. of Polymer Engineering, 2005.
"August, 2005." Title from electronic thesis title page (viewed 11/28/2005) Advisor, Lloyd Goettler; Faculty Reader, Avraam I. Isayev; Department Chair, Sadhan C. Jana; Dean of College, Frank N. Kelley; Dean of Graduate School, George R. Newkome. Includes bibliographical references.

O óleo extensor normalmente empregado em copolímeros à base de butadieno e estireno ( borracha SBR) da série 1712 é o extrato aromático (DAE). Nesta Dissertação, esse óleo foi substituído por óleos com baixos teores de policíclicos aromáticos em formulações de SBR. Esta substituição se deu em atendimento a Regulamentação REACH (EC No1907/2006 do Parlamento Europeu e do Conselho de 18 de Dezembro de 2006, Anexo XVII) que determina que a soma de hidrocarbonetos policíclicos aromáticos individuais (PAHs) deve ser abaixo de 10 mg/kg e o teor de benzo(a)pireno (BaP) não deve exceder 1 mg/kg. Os óleos empregados foram o extrato aromático residual tratado (TRAE) e dois óleos naftênicos de fornecedores diferentes (HN1 e HN2). As composições de SBR estendidas em DAE, TRAE, HN1 e HN2 tiveram suas propriedades térmicas avaliadas por análise termogravimétrica (TG) e calorimetria diferencial de varredura (DSC). As propriedades físicas foram determinadas por ensaios de tração, dureza, resistência à abrasão e resiliência. Foram ainda avaliadas as propriedades reométricas e reológicas, por viscosidade e relaxação Mooney, respectivamente. Ao final os resultados demonstraram que é possível a substituição do óleo extensor por quaisquer dos óleos testados sem prejuízos nas propriedades estudadas
The extender oil usually employed in compositions of rubbers based on sytrene and butadiene (SBR) 1712 is the aromatic extract DAE. In this Dissertation, this oil was substituted by oils with low levels of polycyclic aromatic hydrocarbons: the treated residual aromatic extract (TRAE) and two naphthenic oils from different suppliers (HN1 and HN2). This substitution was performed in response to REACH Regulation (EC No1907/2006 European Parliament and the Council of 18 December 2006, Annex XVII) which state that the sum of individual polycyclic aromatic hydrocarbons (PAHs) should be below 10 mg / kg and the levels of benzo (a) pyrene (BaP) should not exceed 1 mg / kg. SBR compositions extended with DAE, TRAE, HN1 and HN2 were characterized in terms of thermal properties by thermogravimetry (TG) and differential scanning calorimetry (DSC), rheometric properties, physical properties (tension tests, hardness, abrasion resistance and resilience) and rheological (viscosity and Mooney relaxation). The final results showed that it is possible to replace the extender oil DAE for any of the tested oils without loss in the studied properties

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

Strukturiranje elastomernih kompozita dodavanjem različitih vrsta nanopunila je dovelo do značajnog poboljšanja njihovih primenskih svojstava, a samim tim i do povećanja njihove potencijalne primene kao pogodnih materijala za specijalne namene. U ovom radu, dobijene su dve grupe elastomernih hibridnih materijala za specijalne namene (na osnovu stirenbutadienskog elastomera i na osnovu termoplastičnih poliuretana).U prvom delu istraživanja, veliki doprinos u razvoju industrije gume je postignut strukturiranju stirenbutadienskih nanokompozita primenom nanočestica punila silicijum(IV)oksida različitih morfoloških svojstava, dobijenih hidrotermičkom i termičkom obradom, primenom tri eksperimentalno modelovana punila silicijum(IV)oksida (dobijena taloženjem iz Na-vodenog stakla sa sumpornom kiselinom), kao i hibridnog punila (kombinacije čestica aktivne čađi i SiO₂ optimalnih svojstava). Izvršena je analiza uticaja strukture, površine i površinske aktivnosti nanopunila na ojačanje elastomera, kao i provera koncepata, modela i teorija ojačanja na neumreženim i umreženim sistemima stirenbutadienskih elastomera ojačanih modifikovanim punilima SiO₂. Primenom mnogobrojnih metoda karakterizacije, sveobuhvatno je ispitan uticaj nanopunila na karakteristike mešanja, reološka svojstva pripremljenih hibridnih nanokompozita, sposobnost umrežavanja u neumreženom materijalu, kao i na toplotna, dinamičko-mehanička i mehanička svojstva umreženih nanokompozita, radi projektovanja i optimizovanja sastava SBR hibridnih materijala za razvoj modelnog protektora sa optimalnim svojstvima za ekološke ili "zelene pneumatike". Drugi deo istraživanja je bio posvećen dobijanju segmentiranih poliuretanskih elastomernih nanokompozita primenom alifatičnih polikarbonatnih diola i nanočestica bentonita, koji nalaze primenu u medicini, građevinarstvu, u industriji nameštaja i sportske opreme. Primenom mnogobrojnih metoda za karakterizaciju, ispitan je složen mehanizam uticaja tvrdih segmenata, termodinamičke nekompatibilnosti i prisustva nanočestica punila bentonita na strukturu i morfologiju, kao i na toplotna i dinamičko-mehanička svojstva pripremljenih poliuretanskih termoplastičnih elastomera. Dobijeni podaci o obrazovanju vodoničnih veza, termičkoj stabilnosti i termičkoj dekompoziciji, kao i o temperaturama prelaska u staklasto stanje i oblasti raskidanja čvorova fizičkih veza, predstavljaju značajan doprinos napretku strukturiranja poliuretanskih elastomera i nanokompozita na osnovu alifatičnih polikarbonatnih diola, i omogućavaju primenu ovih materijala za specijalne namene.
The structuring of elastomeric composites by addition of different nanofillers has led to a significant improvement of their end-use properties, and therefore, to their potential application as suitable materials for special applications. In this work, two types of elastomeric hybrid materials for special purposes were obtained (based on styrene-bustadiene elastomer or on segmented thermoplastic polyurethanes).In the first part of the study, a major contribution to the development of the rubber industry was achieved by structuring styrene-butadiene nanocomposites, applying silica nanoparticles of various morphological properties: prepared by hydrothermal or thermal treatment, three experimentally prepared SiO2 fillers (obtained by precipitation from sodium silicate with sulfuric acid), as well as a hybrid filler (combination of carbon black and SiO2 fillers with optimal properties). The analysis of the influence of the nanoparticles structure, surface and surface activity on the reinforcment of SBR elastomers, as well as the verification of concepts, models and reinforcement theories on non-cross-linked and cross-linked systems of styrene-butadiene nanocomposites was performed. Using the numerous characterization methods, the influence of nanofillers on the mixing characteristics, the rheological properties of the prepared hybrid nanocomposites, as well as the thermal, dynamic-mechanical and mechanical properties of cross-linked SBR nanocomposites was studied, in order to design and optimize the composition of SBR hybrid materials for development of environmental friendly or "green" tyre protector model.The second part of the research was devoted to the preparation of segmented polyurethane elastomeric nanocomposites using aliphatic polycarbonate diols and bentonite nanoparticles, that have found the significant application in the medicine, construction, the furniture and sports equipment industry. Applying numerous characterization methods, a complex mechanism of the influence of the hard segments, thermodynamic incompatibility and the presence of bentonite filler on the structure and morphology, as well as on the thermal and dynamic-mechanical properties of the synthesized thermoplastic elastomers was studied. The obtained data on the hydrogen bonds formation, thermal stability and thermal decomposition, as well as the glass transition temperature and physical crosslink disruption temparature range, makes a significant contribution to the progress in structuring of polycarbonate-based polyurethane elastomers and their hybrid materials, and improves their potential applications for the special purposes.

O crescimento dos países em desenvolvimento aumentará em várias vezes o consumo de energia, materiais e alimentos. Para suprir essa demanda é necessário o aproveitamento racional dos resíduos gerados por processos industriais, agrícolas e lixo urbano, transformando-os em energia economicamente competitiva com as outras formas de energia, e em materiais com propriedades otimizadas. O objetivo do presente trabalho foi comparar o comportamento da sílica da casca de arroz obtida por pré-hidrólise ácida seguida de calcinação controlada (Sil-PH) com sílicas de casca de arroz comerciais obtidas simplesmente pela queima da casca (Sil-B e Sil-C) e com a sílica comercial obtida da areia quartzítica (Sil-Z), como carga de reforço em borracha de estireno-butadieno (SBR), que é a mais usada na indústria de fabricação de pneus. Estudos foram conduzidos em SBR 1502, preparados conforme norma ASTM 3191-2010. Foram adicionadas à borracha as sílicas em concentrações de 0, 10, 20 e 40 ppcb. Foram conduzidos testes físicos, químicos, mecânicos, reométricos, dinâmico-mecânicos e análise térmica, bem como ensaios de inchamento dos corpos de prova em toluol e análise microestrutural das sílicas e dos compostos por microscopia eletrônica de varredura, com o objetivo de determinar a natureza do reforço. O número de ligações cruzadas foi avaliado e a energia de formação dessas ligações foi calculada. A relação entre as metodologias de cálculo da densidade de ligações cruzadas foi também avaliada, obtendo a caracterização desse tipo de carga de reforço não somente por correlações mecânicas mas também pela energia de formação das ligações. Os resultados mostraram que quanto maior a adição de sílica, maior é sua interação com a borracha. Dentre as sílicas adicionadas, Sil-Z alcançou os maiores valores de propriedades mecânicas dos compostos, e Sil-PH mostrou os melhores resultados dentre as sílicas de casca de arroz. Por avaliação por inchamento em toluol (teste estático) e por testes de tração e testes dinâmicos foi possível afirmar que as densidades de ligações cruzadas estão correlacionadas, Usando os resultados de reometria e as equações de Arrhenius estimou-se uma energia média de ligação, concluindo que esta corresponde a uma ligação do tipo covalente. Pelos valores de tan ? confirmou-se que os compostos com Sil-PH têm maior aderência no chão molhado do que aqueles com Sil-Z. A sílica nos compostos tende a diminuir a temperatura de transição vítrea. Os resultados da análise térmica mostraram elevada estabilidade térmica dos compostos com Sil-PH e Sil-Z. A falta de cominuição adequada da Sil-PH ocasionou uma dispersão irregular da sílica na SBR, uma molhabilidade parcial da sílica pela borracha e pelo agente de acoplamento, com consequente aparecimento de falhas na estrutura do composto. Por esse motivo as propriedades mecânicas dos compostos com Sil-PH foram inferiores às dos compostos com Sil-Z.
Developing countries are increasing by several times their consumption of energy, materials, and food. To attend their demand it is necessary to rationally reuse industrial, agricultural, and municipal solid waste residues, transforming them into economically competitive energy and materials with optimized properties. The objective of this work was to compare the behavior of a rice husk silica obtained by acidic prehydrolysis and controlled calcination (Sil-PH) with commercial amorphous silicas obtained from quartzite sand (Sil-Z) and from simply burned rice husks (Sil-B and Sil-C), as reinforcing filler in styrene-butadiene rubber (SBR) composites, which is the most used rubber in the tire manufacture industry. Studies were conducted on SBR 1502 rubber according to ASTM 3191-2010 in which amorphous silicas obtained from rice husk and quartzite silica were added at concentrations of 0, 10, 20, and 40 phr. Physical, chemical, mechanical, rheometric, dynamic-mechanical tests, thermal analysis, swelling studies in toluol and scanning electron microscopy of the silicas and composite specimens were made with objective to determine the nature of reinforcement. The number of crosslinks was evaluated and the energy of formation of these bonds calculated. The correlation between the methodologies of calculation of crosslink density was also evaluated, getting the characterization of this type of reinforcing filler not only by mechanical correlations but also by the energy of their formation. The results showed that the higher the content of added silica, the greater the interaction with rubber. According to the mechanical properties values Sil-Z achieved the highest properties values but Sil-PH showed better results compared to the other types of rice husk silicas. By evaluation by swelling in toluene (static), tensile tests and dynamic tests it was possible to affirm that the crosslink densities are correlated. By using the rheometry results and the Arrhenius equations the average bound was estimated to be of a covalent type. The silica in the compounds tends to lower the values of the glass transition temperature. The evaluation of tan ? showed that Sil-PH has more stickiness on the wet floor, which is an important property to tire application. Due to the lack of appropriate grinding of the Sil-PH the dispersion of the silica on SBR was irregular; partial wetting of the silica particles by rubber and silane had also occurred. Those facts had caused failures on the compound structural integrity, with a consequent lowering of the mechanical property values as compared to the compounds with Sil-Z addition.

Les ligands etudies ont ete utilises d'une part en association avec des complexes cationiques du palladium en reactions de dimerisation de l'acrylate de methyle, de codimerisation de l'acrylate de methyle et du butadiene-1,3 et de telomerisation de ce dernier avec le methanol; d'autre part en association avec des complexes de rhodium dans l'hydroformylation de l'hexene-1 de styrenes et de l'acrylate de methyle

Ce travail concerne l'étude des modifications de nanocharges lamellaires synthétiques (α-ZrP) et de leur influence sur les propriétés mécaniques et barrière aux gaz de nanocomposites à matrice élastomère (SBR). Cette étude s'inscrit dans le cadre de l'amélioration de l'étanchéité des pneumatiques. L'une des originalités de ce travail a résidé dans l'introduction des nanocharges hydrophiles par le biais d'une dispersion aqueuse (slurry), dans la matrice SBR hydrophobe. La première phase de ce travail a consisté à entreprendre plusieurs types de modification des nanocharges afin d'étudier les mécanismes d'intercalation et/ou d'exfoliation des ces dernières dans le slurry. Ces différentes familles de charges modifiées ont été utilisées pour réaliser des nanocomposites selon différentes voies de mise en oeuvre : principalement solvant et latex. Nous avons ensuite étudié l'influence, (i) de la nature des intercalants, (ii) des distances interfoliaires initiales des nanocharges et (iii) des procédés de mise en oeuvre des nanocomposites, sur la morphologie et les propriétés finales des matériaux. Cette étude a montré la synergie de ces trois paramètres et mis en évidence l'importance du contrôle des interactions charges modifiées/matrice sur les propriétés de transport de gaz. Parmi l'ensemble des matériaux synthétisés, nous avons pu mettre en avant une formulation, permettant d'atteindre des propriétés mécaniques et barrière intéressantes. Cette formulation, en voie latex, est basée sur l'utilisation de la charge modifiée aminosilane et de l'agent de couplage Si69

博士
國立臺灣大學
環境工程研究所
84
Rubber samples, including polybutadiene rubber (BR), styrene- butadiene rubber (SBR), mixture of BR/SBR and tire tread, were pyrolyzed under nitrogen atmosphere for studying the phenomena of pyrolysis reaction, respectively. A temperature- programmed dynamic thermogravimetric analysis (TGA) was used for meeting the requirement of experimental purposes. Simplified reaction schemes were also proposed for describing the mass-loss behavior of rubber samples, and good agreements between the results of model prediction and those of experiments were obtained. The results of this study may be of great use for the design of rubber waste pyrolysis processes. The mass-loss phenomena for pyrolysis of BR may be attributed to two different reactions deduced from the mass-loss curves of experimental results. The mass ratio of the two reactions was 0.195/0.805. The averaged R-square value between experimental results and model prediction was 0.9903. The mass-loss behavior of SBR pyrolysis may be attributed to three reactions identified from the mass-loss curves of experimental results. The averaged R-square value between experimental results and model prediction was 0.9952. As for mixtures of BR/SBR, the mass-loss rates of pyrolysis reaction may be determined by combination of the corresponding rates for each components. The averaged R-square value between experimental results and model prediction was 0.9831. The mass-loss history for pyrolysis of tire tread may be attributed to three different reactions identified from the mass-loss curves of experimental results. The averaged R-square value between experimental results and model prediction was 0.9834.

碩士
中原大學
化學研究所
95
The study focuses on modifying and grafting of commercial Styrene-Butadiene rubber (SBR). SBR rubber is a high adhesive material that is poor compatibility with other materials. The poor compatibility greatly limits the application of SBR rubber in many application areas. Therefore, SBR rubber must incorporate some functional groups or polar monomers in the polymer chains that increase its property. This study hopes that functional groups and PMMA groups introduced onto SBR can increase its polarity and compatibility with polar polymers. In the experiment, hydroboration was carried out by using 9-BBN to react with the double bonds on side chains of the SBR rubber. The functional polymer (SBR-OH) was obtained by the oxidation on the hydroborated side chain of the copolymer. The grafted copolymerization of PMMA onto SBR rubber was prepared by two different methods by borane chemistry and by ATRP method. First method, the hydroborated on the side chain of the copolymer and then grafted PMMA on the copolymer by oxidation. At second method, the PMMA grafted copolymer was prepared by oxidation, ring-open, ester reaction, and ATRP. We discussed the experimental results via the amount of oxygen, MMA and 9-BBN, and reaction time etc. The structure and grafting efficiency of graft copolymers will be characterized and determined by 1H-NMR and FTIR. Additionally, use DSC and TGA to discuss the variation of thermal properties before and after the functionalized or grafted reaction. At last, the graft copolymers can be used as a compatibilizer to improve materials compatibility and the morphology of blends are compared by using SEM.

Styrene-butadiene rubber (SBR) copolymer nanosized latex particles were synthesized via differential microemulsion polymerization (DMP) in a 300ml bench-scale semi-batch reactor, equipped with a thermocouple and a magnetic four-blade stirrer. This approach employed a continuous and slow addition of styrene and butadiene monomers drop-wise into a continuous aqueous phase comprising DI water, an initiator, a surfactant and a chain transfer agent. It was found that this approach offered an efficient heterogeneous phase path to synthesize styrene-butadiene copolymer latices with a high-butadiene-level of the resulting latex particles. The latex nanoparticles were formed as the SBR copolymer monomers undergo a self-assembly process in the continuous phase and were stabilized by their surrounding surfactant particles. The size of the latex particles could be easily adjusted by alternating the monomer addition speed, the reaction temperature, the amount of chain transfer agent applied and the type and the amount of surfactant introduced in the process. Not surprisingly, a small amount of chain transfer agent introduced into the DMP system might facilitate micellar nucleation and reduction of gel content in the polymer dramatically and may also aid increasing the size of the SBR latex particles. Owing to the small size of SBR latices prepared by the DMP method, the glass transition temperature (Tg) of the latices is much lower than the SBR latices generated by conventional technique. Furthermore, the increase of Tg was observed with an increase of the SBR particle size.

碩士
國立臺灣大學
化學工程學研究所
106
Since the industrial revolution, human life has enjoyed great progress, but it has also caused great harm to the natural environment. With the rise of environmental awareness in recent years, the tire industry has invested a lot of resources in developing green (fuel-efficient) tires. The performance of tires is often characterized by the so-called magic triangle, including the rolling resistance, the wet traction and the wear. However, these three performance indicators are very difficult to improve at the same time. Improving one will usually make the other worse. However, the goal of green tire is to reduce the rolling resistance without sacrificing the other two. This magic progress is mainly achieved by mixing the silica nanoparticles into the tread compound. In order to further improve the performance of green tires, especially the grip and fuel economy, this study investigated the effect of the addition of hydrocarbon resin on the dynamic properties of the tread compound. First, we determined the solubility parameters of three hydrocarbon resins (supplied by ExxonMobil) to understand the affinity of these hydrocarbon resins with various rubbers in the tread compound. Next, we used a liquid phase mixing process and a solid phase mixing process to verify the miscibility of the resins with different rubbers. From the liquid phase mixing process, we found that these three resins can only be miscible with styrene-butadiene rubber, and we also confirmed from the solid phase mixing process that the resins are miscible with natural rubber and styrene-butadiene rubber (25:75). From the results of differential scanning calorimetry (DSC) and dynamic mechanical analysis (DMA), we speculate that the influence of hydrocarbon resins on the dynamic properties of natural rubber and styrene-butadiene rubber blending system can be attributed into two mechanisms. First, addition of the resins increase the system''s glass transition temperature, which in turn improves the wet grip of the tire. However, this mechanism also increases rolling resistance of the compound. The second is that the hydrocarbon resin can improve the dispersibility of the fillers, thereby increasing the wet grip and reducing the rolling resistance. This argument is supported by the measurement of the Payne effect. These two mechanisms have positive contribution to the wet grip of the tire, but have opposite effects on the rolling resistance. According to the experimental results of the silica-filled tread compound, we found that adding 10 phr of resin can greatly improve the wet grip (30-40%), but will increase the rolling resistance slightly (0-10%). However, if more resin is added, the rolling resistance will be greatly increased, which will adversely affect the fuel saving requirements.

The polymer materials industry is heavily dependent on the use of petroleum based plastics. This poses a problem, as the world is facing ongoing petroleum supply problems. A need exists for a bio-carbon based polymer material that has the performance and cost of currently used petroleum plastics. However, the overall performance of current bio-based plastics indicate that they must be somehow supplemented to achieve the properties of that of petroleum-based polymers. The low impact strength and thermal stability of poly(lactic acid), PLA are targets for improvement. One option is for development is through blending with acrylonitrile butadiene styrene (ABS). The viability and efficacy of using these two polymers as blending partners is investigated. The PLA used in these studies has unique and interesting crystallization properties. These have been examined and detailed in part 1. The second part of study includes neat polymer properties, miscibility analysis, and large scale process results. This results in an optimized blending ratio on which to go forward with development. The mechanical, thermal, and morphological properties are investigated in these studies. Significance of this research and development is widespread, as the material developed has the potential to reduce the use of petroleum-based carbon in plastics.
The financial support from the 2010 Ontario Ministry of Agriculture, Food and Rural Affairs (OMAFRA)/University of Guelph -Bioeconomy for Industrial Uses Research Program, Natural Sciences and Engineering Research Council (NSERC) AUTO21 NCE project and Grain Farmers of Ontario (GFO), to carry out this research is gratefully acknowledged.

In the field of tyre technology, silica filled tyres are generally considered as a lower energy consumption product due to their lower rolling resistance characteristics. Additionally, they can offer excellent grip on the wet and snowy conditions which are more essential from the safety perspective. However, the proper dispersion of the silica in rubber compounds is one of the challenging tasks to engineers, physicist and chemist. In this thesis, a very controlled in-situ silica based solution styrene butadiene rubber composites were developed and intensively investigated by the synthesis of sol-gel silica in presence of polymer solution. It means the silica particles were allowed to grow in the presence of rubber in the reaction mixture. It was observed that the sizes of the synthesized silica particles are rather larger than standard precipitated commercial silica particles. In depth morphological investigation revealed that the obtained sol-gel silica particles appear in strong cluster form with primary particle size of 10 - 15 nm and final aggregated size of 200 to 400 nm. Nevertheless, the final mechanical performance and other rubber related properties of in-situ derived silica composites are better in many important aspects for technical applications as compared with commercial silica at a given loading of fillers. Owing to the presence of more active hydroxyl group on the surface of sol-gel silica, the effective coupling between silica and rubber has been established. Furthermore, the permanent trapped rubber chains inside the large aggregates of sol-gel silica particles enable the compounds to offer good mechanical reinforcement, higher resilience, and dynamic mechanical properties. The present work is a humble approach to pave an alternative novel way for silica-rubber composite preparation in order to minimize the problem of silica mixing with the rubbers.
Auf dem Gebiet der Reifentechnologie zeichnen sich Kieselsäure-(Silika)-gefüllte Reifen aufgrund ihres charakteristisch geringeren Rollwiderstands allgemein als ein Produkt mit geringerem Energieverbrauch aus. Darüber hinaus bieten sie ein hervorragendes Nasshaftvermögen, welches eine essentielle physikalische Kenngröße für die Fahrsicherheit darstellt. Allerdings stellt eine optimale Dispergierung der Silikafüllstoffs in Kautschukmischungen eine anspruchsvolle Aufgabe für Ingenieure, Physiker und Chemiker dar. Im Rahmen der vorliegenden Arbeit wurden Silika / Styrol-Butadien-Kautschuk-Verbundwerkstoffe mittels eines in-situ Sol-Gel-lösungsmittelbasierten Reaktionsverfahrens entwickelt. Diese Technologie beruht auf der Nukleierung von Kieselsäure-Partikeln in Gegenwart des Elastomers in einer Syntheselösung. Dabei wurde beobachtet, dass die Partikel der so synthetisierten Silika-Teilchen größer sind, als die eines kommerziellen Standard-Silika-Füllstoffs. Eine umfassende morphologische Untersuchung zeigt, dass die in-situ synthetisierten Silikapartikel sphärisch sind und eine Primärteilchengröße von 10 bis 15 nm aufweisen. Diese nanoskaligen Teilchen agglomerieren sich zu größeren sphärischen Clustern mit einer Größe von 200 bis 400 nm und weisen somit eine andere Morphologie auf, als die kommerziell erhältlichen Silika-Füllstoffe. Die statisch- und dynamisch-mechanischen Eigenschaften, sowie weitere elastomerbezogene Eigenschaften der in-situ synthetisierten Silika/Styrol-Butadien-Kautschuk-Verbundwerkstoffe, wie z.B. Rückprallelastizität, mechanisch induzierte Wärmeentwicklung und Spannung-Dehnungshysterese, zeigen verbesserte Werte im Vergleich zu Elastomermaterialien gefüllt mit kommerzieller Kieselsäure. Eine erhöhte Anzahl von Hydroxylgruppen auf der Oberfläche der in-situ synthetisierten Silikapartikel, verbunden mit permanenter Adsorption der Polymerketten des Elastomers auf der Teilchenoberfläche ermöglicht die Ausbildung eines Elastomerverbundes mit verbesserter mechanischer Verstärkung mit oder ohne Einsatz eines haftvermittelnden Silans, wie z.B. TESPT (Bis [3-(triethoxysilyl)propyl]-tetrasulfid). Die Wechselwirkungen zwischen Elastomer und Füllstoff, zwischen den Füllstoffpartikeln, sowie der Verstärkungsmechanismus des in-situ synthetisierten Füllstoffes wurden mittels dynamischmechanischer Analyse (Amplitudentests), Festkörper-NMR und energiedispersiver Röntgenspektroskopie umfassend analysiert. Der vorliegende Ansatz verdeutlicht, dass die in-situ Generierung des Füllstoffes im Elastomer ein vielversprechendes und alternatives Verfahren zur Herstellung von Elastomermaterialien mit verbesserter Silika-Dispergierung, sowie erhöhter Elastomer-Füllstoff-Wechselwirkung bietet.

碩士
國立雲林科技大學
化學工程與材料工程系
106
This study mainly uses cellulose fibers(CF) to fill styrene-butadiene rubber (SBR). The interfacial compatibility between SBR and CF has been improved by using 3-aminopropyltriethoxydecane (APTES) as a coupling agent. Firstly, the effect of adding cellulose fibers on the vulcanization characteristics and Mooney viscosity of SBR has been investigated by Mooney viscometer and Vulkameter. It is found that the scorch time (TS2) of the SBR compound is shortened with the increase of CF content while the optimum vulcanization time (TC90) is decreased first and then increased with the increase of CF content. The addition of APTES coupling agent significantly reduces TS2 and TC90. The mechanical properties of SBR/CF composites were investigated by tensile testing machine. The maximum tensile strength of 1.68 MPa is obtained when the CF amount of 10 phr is added. The improvement of CF-filled SBR on the elastic modulus is found to be more significant. The APTES coupling agent also plays a significant role in improving the tensile strength which reachs to 2.37MPa at the added APTES amount of 0.06ml/g CF. Surprisingly, with the increase of polar CF content coupled with the addition of APTES, the contact angle of the SBR/CF composite surface increases. On the other hand, if polar NBR is incorporated, the contact angle of the compound surface decreases with the increase of NBR content. Consequently, the peel strength of the SBR/CF strip bonded to an identical counter strip by a specific PU reactive adhesive increased. Finally, we study the anti-vibration property of the CF-filled SBR composite. A micro-electromechanical system (MEMS) accelerometer has been used to directly measure the micro-vibration. 40 phr of cellulose fiber and silica is filled respectively in SBR for comparison. Meanwhile, dynamic mechanical analyzer (DMA) is also used to measure the damping characteristics(loss tangent, tanδ). Compared with silica, CF-filled SBR composite exhibits better vibration damping than silica-filled SBR.

One of the current problems faced by mankind is the problem of safe disposal of waste rubber. Statistics show that the number of waste tires is continuously increasing at a very rapid rate. Since rubber materials do not decompose easily (due to their crosslinked structure), they end up being a serious ???environmental problem???. An intuitive solution to prevent the accumulation of the scrap tires is to continuously reuse them. A new patented reclamation method was discovered in our laboratory, which makes use of a twin screw extruder (TSE) in order to produce reclaimed rubber (referred as devulcanized rubber (DR) from here on) of very high quality. Also, this method has proven to be more economical than other commercial reclaiming methods. Products made solely from a reclaimed material face challenges from those made by virgin materials because of relatively poor properties. However, the striking advantage of using reclaimed rubbers is the cost reduction. Hence, it is important to work on establishing methods by which these reclaimed rubbers could be efficiently used and incorporated into present day products. The deterioration of properties could be minimized by blending them with varying amounts of other materials. A possibility in this direction is manufacturing of thermoplastic vulcanizates (TPVs) using reclaimed rubber and general purpose thermoplastics. In accordance with this idea, the focus of this research is to prepare DR and polypropylene (PP) based TPVs. DR is unique as the rubber itself consists of two phases- one phase consisting of uncrosslinked (including devulcanized rubber molecules), and the other phase consisting of crosslinked (un-devulcanized) rubber. These un-devulcanized crumbs act as stress concentrators because they do not break-up easily, and lead to poor physical properties. Hence, this project tries to find out ways to increase the interfacial adhesion between the rubber and PP by using reactive and non-reactive techniques. Preliminary experiments were carried out in a batch mixer to compare DR and rubber crumb (CR). DR based TPVs showed better properties than CR based TPVs, however, the properties were not useful for commercial applications. Sulphur based dynamic vulcanization was studied in a batch mixer and found to be not effective in improving the properties of DR based blends. On the other hand, DCP/ sulphur based curing system was found to show significant improvement in properties. Therefore, DCP/sulphur based curing package was studied in detail on the blends consisting of DR and PP. The optimum ratio of DCP/sulphur was found to vary depending on the ratio of DR/PP. A hypothesis regarding the mechanism of DCP/sulphur curing has been proposed, which seem to correlate well with the experimental results observed. Additionally, it was determined that DR prepared from tire rubber (DRT) performed better than DR prepared from waste EPDM (DRE) for the curing system used. Accordingly, experiments on a TSE were carried out using DRT and a combination of compatibilizing resins and curatives. This combination showed a drastic improvement in blends properties and once again the optimum ratio of compatibilizing resins seemed to depend on the ratio of DRT/PP. As a result of the work, successful strategies based on reactive compatibilization techniques were developed in order to prepare useful TPVs having up to 70% DR. A series of compatibilization techniques has been evaluated using design of experiments and various characterization techniques such as mechanical tests, scanning electron microscopy, thermal analysis and crosslink density measurements. This led to the development of a formulation, which could improve the blend properties significantly. A tensile strength of around 10 MPa and an elongation-at-break of 150-180 % could be achieved for devulcanized rubber (70%) based TPVs, which has broadened the scope for its commercial applications. In addition to that, the process was established on a TSE that has enabled a continuous and steady production of these TPVs with reasonable throughputs.

For the development of intelligent vehicle tires, especially for future self-driving cars, suitable strain sensors are mandatory. The design of such a strain sensor must fulfill several criteria and most important of them all, it must be easily mounted or implanted into the tire and the elastic nature of the sensors must synchronize with the deformation of the tire. This work is therefore focused on understanding the piezoresistive characteristics of a composite developed from tire rubber. Thus, a commercially available grade of solution styrene butadiene rubber (SSBR) was primarily chosen as the matrix rubber along with butadiene rubber (BR) and natural rubber (NR). The initial focus was given to develop simple strain sensors by exploiting the concept of piezoresistivity with conductive rubber composites based on SSBR filled with carbon black and carbon nanotubes. As the internal structure of the filler particles was found to rearrange or alter during deformation, it was important to study the piezoresistive performance with respect to critical material parameters such as crosslink density, hardness, and stiffness of the composite in details. The developed sensors were able to be stretched to several hundred percents of their original length and strain sensitivity as much as ~1000 (gauge factor) was achieved. Quasi-static cyclic tests indicated the ability of the developed materials to respond and recover within the given time frame. This motivated to assess the suitability of these materials for dynamic sensing. As a consequence, the dynamic piezoresistive characteristics were studied for the conducting SSBR composites. The temporal changes in electrical resistance of the SSBR composites were monitored real-time during dynamic mechanical studies. The influence of critical parameters such as filler content, test frequency, test temperature, and matrix crosslink density was taken into consideration. The filler network was found to rearrange in the rubber matrix during dynamic loading, witnessed from the changes in electrical resistance over time. The findings offered a preliminary understanding of the filler network behavior inside the SSBR matrix. Situations that eased the filler mobility such as high temperature, low frequency, and low crosslink density resulted in the minimal effect on the filler network changes. For a given strain cycle, the samples responded with two distinct responses pertaining to the loading and unloading, reflecting as two signals. Filler network reconfiguration during unloading was found to be the reason for the second piezoresistive response. The behavior of the second peaks was analyzed in detail at different conditions. The stress relaxation, an inevitable process pertaining to viscoelastic materials, resembled the overall piezoresistance change of the material. The two properties were therefore correlated, and a relationship was deduced, offering the possibility to monitor the mechanical performance using electrical resistance data. Apart from evaluating the phase shifts between stress and strain (δσ-ε) during the dynamic tests, phase shifts were also evaluated between resistance and strain (δR-ε) as well as between stress and resistance (δσ-R). The piezoresistive phase shift values (δσ-R) were found to be larger than the mechanical phase shifts values (δσ-R > δσ-ε) It perceived information regarding the time taken by the filler network to respond for the applied strain. To realize the concept of dynamic piezoresistivity in commercial use, (i) SSBR filled with conventional carbon blacks N220, N330, and N660 and (ii) NR and BR (two more rubbers that are widely used in tire industry) filled with Printex carbon black were tested for their piezoresistive behavior under dynamic conditions. The experimental results were promising and guaranteed the applicability of the concept for all rubber - filler combinations that display piezoresistive characteristics. This basic scientific study would be the stepping stone to understand dynamic piezoresistivity in rubbers, which would help in developing rubber-based sensors that are capable of performing under dynamic conditions for the future. Moreover, the study offered a much deeper insight not only on the dynamic piezoresistivity but also on the behavior and changes in the filler network during dynamic deformation.
Für die Entwicklung von intelligenten Fahrzeugreifen, insbesondere für zukünftige selbstfahrende Autos, sind geeignete Dehnungssensoren notwendig. Die Konstruktion eines solches Sensors muss mehrere Kriterien erfüllen: am wichtigsten ist, dass er einfach in den Reifen eingebaut oder implantiert werden kann und dass die Verformung des Sensors mit der Verformung des Reifens synchronisiert ist. Daher konzentriert diese Arbeit sich auf das Verständnis der piezoresistive Eigenschaften eines bekannten Reifenkautschuks, gefüllt mit leitfähigen Füllstoffpartikeln. Eine kommerziell erhältliche Sorte von Lösungs-Styrol-Butadien-Kautschuk (SSBR), Butadien-Kautschuk (BR) und Naturkautschuk (NR), welche in der modernen Reifenindustrie weit verbreitet sind, wurden deshalb als Matrix-Kautschuk gewählt. Der Fokus lag zunächst auf der Entwicklung einfacher Dehnungssensoren unter Ausnutzung des Konzepts der Piezoresistivität mit leitfähigen Gummimischungen auf Basis von SSBR, welche mit leitfähigem Ruß und Kohlenstoff-Nanoröhrchen gefüllt sind. Da sich die innere Struktur der Füllstoffpartikel während der Verformung verändert, war es wichtig, das piezoresistive Verhalten in Bezug auf kritische Materialparameter wie Vernetzungsdichte, Härte und Steifigkeit des Komposits im Detail zu untersuchen. Die Sensoren konnten auf mehrere hundert Prozent ihrer ursprünglichen Länge gestreckt werden, wobei eine Empfindlichkeit bis zu ~1000 (Gauge Faktor) erreicht wurden. Quasistatische zyklische Tests zeigten die Fähigkeit der entwickelten Materialien, innerhalb des vorgegebenen Zeitrahmens zu reagieren und sich zu erholen. Dies motivierte dazu, die Eignung dieser Materialien für die dynamische Sensorik zu beurteilen. In der Folge wurden die dynamischen piezoresistiven Eigenschaften für die elektrisch leitfähigen SSBR-Verbundwerkstoffe untersucht. Die zeitlichen Veränderungen des elektrischen Widerstandes dieser SSBR-Verbundwerkstoffe wurden während dynamisch-mechanischer Studien in Echtzeit überwacht. Der Einfluss kritischer Parameter wie Füllstoffgehalt, Matrixvernetzungsdichte, Messfrequenz, und Messtemperatur wurde dabei berücksichtigt. Es wurde festgestellt, dass sich das Füllstoffnetzwerk während der dynamischen Belastung in der Elastomermatrix neu anordnet, wie die Veränderungen des elektrischen Widerstands im zeitlichen Verlauf zeigen. Diese Ergebnisse bieten ein vorläufiges Verständnis des Verhaltens des Füllstoffnetzwerks der SSBR-Matrix. Situationen, die die Füllstoffmobilität begünstigen, wie hohe Temperatur, niedrige Frequenz und niedrige Vernetzungsdichte, führten zu minimalen Auswirkungen auf das Füllstoffnetzwerk. Für einen gegebenen Dehnungszyklus reagierten die Proben mit zwei getrennten Signalen, welche dem Be- und Entlasten des Materials entsprechen und sich als zwei Peaks in der Widerstandsmessung widerspiegeln. Der Grund für das zweite piezoresistive Signal ist die Rekonfiguration des Füllstoffnetzwerks während der Entlastung. Das Verhalten dieser zweiten Peaks wurde unter verschiedenen Bedingungen detailliert analysiert. Die Spannungsrelaxation, ein unvermeidlicher Prozess bei viskoelastischen Materialien, ähnelte der gesamten Piezowiderstandsänderung des Materials. Diese beiden Eigenschaften wurden daher korreliert und ein Zusammenhang abgeleitet, der die Möglichkeit bietet, die mechanische Leistung anhand von elektrischen Widerstandsdaten zu überwachen. Neben der Auswertung der Phasenverschiebungen zwischen Spannung und Dehnung (δσ-ε) bei dynamischen Tests wurden auch die Phasenverschiebungen zwischen Widerstand und Dehnung (δR-ε) sowie zwischen Spannung und Widerstand (δσ-R) bewertet. Die piezoresistiven Phasenverschiebungswerte (δσ-R) erwiesen sich als größer als die mechanischen Phasenverschiebungswerte (δσ-R > δσ-ε). Dies bietet Informationen über die Zeit, die das Füllernetzwerk benötigt, um auf eine angelegte Belastung zu reagieren. Um das Konzept der dynamischen Piezoresistivität im kommerziellen Einsatz zu realisieren, wurden (i) SSBR gefüllt mit konventionellen Rußen N220, N330 und N660 und (ii) NR und BR (zwei weitere Kautschuke, die in der Reifenindustrie weit verbreitet sind) gefüllt mit leitfähigem Ruß auf ihr piezoresistives Verhalten unter dynamischen Bedingungen getestet. Die experimentellen Ergebnisse sind vielversprechend und garantieren die Anwendbarkeit des Konzepts für alle Gummi-Füllstoff-Kombinationen mit piezoresistiven Eigenschaften. Diese grundlegende wissenschaftliche Studie ist ein wichtiger Schritt, um die dynamische Piezoresistivität in Kautschuken zu verstehen, was bei der Entwicklung von zukünftigen, dynamisch arbeitenden Sensoren auf Kautschukbasis helfen kann. Darüber hinaus liefert diese Studie einen viel tieferen Einblick nicht nur in die dynamische Piezoresistivität, sondern auch in das Verhalten und die Veränderungen im Füllstoffnetzwerk während der dynamischen Verformung.