bluuebunny/crossref_metadata_2025_split huggingface dataset:
Reinforcing Effect of Silica and Silane Fillers on the Properties of Some Natural Rubber Vulcanizates
Authors: Ansarifar A. , Nijhawan R. , Nanapoolsin T. , Song M. 
Published: February 2011

Abstract
The reinforcing effect of up to 6 parts per hundred rubber by weight (phr) bis- (3-triethoxysilylpropyl) tetrasulfide (TESPT), a bifunctional organosilane, on the crosslink density, bound rubber, and technical properties of some conventional accelerator/sulfur compounds of natural rubber, containing 30 phr precipitated amorphous white silica was studied. The crosslink density and bound rubber improved as a function of TESPT loading. The tensile strength, elongation at break, stored energy density at rupture, and cohesive tear strength deteriorated at low loading of TESPT, but they subsequently increased after the full amount of TESPT was introduced into the compound. The improved properties of the vulcanizate was due to the better dispersion of the filler in the rubber matrix. However, the cyclic fatigue life was adversely affected, and the hardness hardly changed as a result of adding TESPT to the rubber.
Thermomechanical Degradation of SBR During Ultrasonic Treatment under the Static Conditions
Authors: Yashin V. V. , Hong C. K. , Isayev A. I. 
Published: February 2011

Abstract
The paper presents the results of experimental and theoretical studies of the ultrasonic treatment of ground vulcanized unfilled styrene-butadiene rubber (SBR) in a static device (no flow). Degradation of the rubber network took place during the treatment. Crosslink density and gel fraction were measured in the samples ultrasonically treated at various pressures, ultrasonic amplitudes and exposure times. Consumption of the ultrasonic energy was also monitored. The structural characteristics of SBR ultrasonically treated under static conditions have been found to be significantly different from those reported previously for the continuous process. Theoretical calculations have demonstrated that the observed differences could be attributed to a partial depolymerization of broken rubber chains caused by a significant temperature rise in the course of ultrasonic treatment under static conditions. It has also been shown that the non-linearity of compressibility of a thin ground rubber layer has to be taken into account in the calculations of ultrasonic power consumption.
Fatigue of Cord-Rubber Composites: V. Cord Reinforcement Effect
Authors: Song J. H. , Costanzo F. , Lee B. L. 
Published: February 2011

Abstract
Fatigue behavior of cord-rubber composite materials forming the belt region of radial pneumatic tires has been characterized to assess their dependence on stress, strain and temperature history as well as materials composition and construction. Estimated at various levels of stress amplitude were the fatigue life, the extent and rate of resultant strain increase (“dynamic creep”), cyclic strains at failure, and specimen temperature. Reflecting their matrix-dominated failure modes, such as cord-matrix debonding and delamination, composite laminates with different cord reinforcements showed the same S-N relationship as long as they were constructed with the same rubber matrix, the same cord angle, similar cord volume, and the same ply lay-up. The interply shear strain of 2-ply ‘tire belt’ composite laminate under circumferential tension was affected by twisting of specimen due to tension-bending coupling. However, a critical level of interply shear strain, which governs the gross failure of composite laminate due to the delamination, appeared to be independent of different lay-up of 2-ply vs symmetric 4-ply configuration. Because of much lower values of single cycle strength (in terms of gross fracture load per unit width), the composite laminates with larger cord angle and the 2-ply laminates exhibited exponentially shorter fatigue lifetime, at a given stress amplitude, than the composite laminates with smaller cord angle and 4-ply symmetric laminates, respectively. Maximum cyclic strain of composite laminates at failure, which measures the total strain accumulation for gross failure, was independent of stress amplitude and close to the level of static failure strain. For all composite laminates under study, a linear correlation could be established between the temperature rise rate and dynamic creep rate which was, in turn, inversely proportional to the fatigue lifetime.
Dependence of Physical Properties and Processing Behavior of Blends of Silicone Rubber and Fluororubber on Blend Morphology
Authors: Ghosh Arun , De† S. K. 
Published: February 2011

Abstract
The paper reports that the processing behavior and physical properties of the blends of silicone rubber and fluororubber based on tetrafluoroethylene/propylene/vinylidene terpolymer. The processing behavior of the fluororubber can be improved on blending with low viscous silicone rubber. The results indicate that the processing behavior, mechanical properties, surface energies, and flammability of the blends are controlled by the blend morphology. Surface morphology of the blends show that blends of two rubbers are microheterogeneous and biphasic structure, wherein silicone rubber acts as a continuous matrix with the fluororubber as a dispersed phase.
Gum and Black-Filled Double Networks of cis-1,4-Polyisoprene Crosslinked with Sulfur Donors: Part I. Tensile Properties
Authors: Hamed G. R. , Umetsu K. 
Published: February 2011

Abstract
Gum and black-filled double networks of cis-1,4 polyisoprene, crosslinked with sulfur donors, have been prepared by first partially curing sheets, then stretching them and completing cure. Double networks are anisotropic and exhibit a residual extension ratio λr, which is higher for filled compared to gum samples. Additionally, double networks of filled specimens have higher anisotropy than gum counterparts, presumably because carbon black promotes chain alignment and strain-crystallization. Tensile specimens cut parallel to the stretch direction are stiffer, less extensible, and sometimes stronger than simple isotropic networks, while perpendicular specimens have stress-strain responses much like that of the isotropic control.
Mechanism of Improved Aged Rubber-to-Brass Adhesion Using One-Component Resins
Authors: Patil Pankaj Y. , van Ooij William J. 
Published: February 2011

Abstract
Using a squalene liquid rubber modeling approach, we have shown recently that the role of an adhesion promoting one-component resin system is similar to the conventional resorcinol based two-component resin system1. However, to further study the effect of resins in real natural rubber based formulations, eight similar formulations were mixed to make compounds in natural rubber. These rubber compounds were characterized and tested for their mechanical properties viz. stress at break, stress at 300% strain, elongation %, initial, heat and humidity aged wire adhesion pull-out test, tensile tear strength test. Furthermore, to confirm our proposed theory of the migration of resins from the rubber matrix towards the surface, the surfaces of the rubber compounds were studied using ATR-FTIR spectroscopy. NMR spectroscopy was performed on the rubber compounds to study the sulfur crosslink density distribution. Based on our new findings relating to improved corrosion performance of sulfidized brass cords a theory has been put forward that loss of rubber-to-brass adhesion is in fact due to the aging of the brass cord. This aging of brass cord is found to be due to the dissolution of iron from the steel cord. It was observed that the use of different formulations affected the corrosion performance of the sulfidized brass cords in a different manner. The use of resins, particularly one-component resins, seemed to inhibit this iron dissolution thus resulting in durable rubber-to-brass adhesion even in the humidity aged adhesion blocks.
Investigation of the Payne Effect and its Temperature Dependence on Silica-Filled Polydimethylsiloxane Networks. Part II: Test of Quantitative Models
Authors: Clément F. , Bokobza L. , Monnerie L. 
Published: February 2011

Abstract
The results obtained in Part I, on Polydimethylsiloxane (PDMS) networks filled with treated Aerosil A300 silica at variable temperature and various loadings, have been used to test the quantitative models of the Payne effect proposed by Kraus, Huber-Vilgis, and Maier-Göritz. Each model is able to account only for a part of the experimental results: Kraus and Maier-Vilgis for the variation of the Payne effect with filler volume fraction, Maier-Göritz for the influence of temperature on the Payne effect. But neither of these quantitative models is able to fit the whole set of experimental results on G′ and G″ with a unique set of parameters.
Reinforcement and Nonlinear Viscoelasticity of Polymer Melts Containing Mixtures of Nanofillers
Authors: Sternstein S. S. , Ramorino G. , Jiang B. , Zhu Ai-Jun 
Published: February 2011

Abstract
The reinforcement and concomitant nonlinear viscoelastic behavior have been investigated for several composites of linear polymer melt with various binary mixtures of nanofillers having different surface chemistries and particle sizes. The dependence of storage modulus and loss factor on dynamic shear strain amplitude has been obtained for several compositions of each binary filler pair. Composites with mixed fillers display nonlinear interactions that are filler pair/matrix specific. Total filler concentration appears to be a major factor, suggesting that nearest neighbor particle spacing is crucial even if the neighbors are of a different filler type. The results are consistent with the theory recently proposed by Sternstein and Zhu in which the high reinforcement by nanofillers is due to the trapping of entanglements and the resultant effects on matrix chain mobility and entropic elasticity. At high strain amplitudes, the storage modulus and loss factor of the composites with binary filler mixtures are found to be nearly independent of the filler mixture ratio, and dependent only on the total filler concentration. A “partial molar” storage modulus for mixed filler composites is defined for future considerations, and specific interactions are presented for two binary filler systems.
The Reinforcement and Crosslinking of Styrene Butadiene Rubber with Silanized Precipitated Silica Nanofiller
Authors: Ansarifar A. , Wang L. , Ellis R. J. , Kirtley S. P. 
Published: February 2011

Abstract
Synthetic precipitated amorphous white silica nanofiller was used to reinforce and crosslink styrene-butadiene rubber (SBR). The silica surfaces were pre-treated with bis[3-triethoxysilylpropyl-)tetrasulfide (TESPT) bifunctional organosilane. TESPT chemically adheres silica to rubber and also prevents silica from interfering with the reaction mechanism of sulfur-cure. The silica particles were fully dispersed in the rubber, which was cured primarily by using sulfur in TESPT, or, by adding elemental sulfur to the cure system. The cure was also optimized by incorporating different accelerators and activators in the rubber. This study showed that the silica particles could be used both as crosslinking and reinforcing filler in the rubber.
Study on Crosslinking in Diimide Reduction of Nitrile Butadiene Rubber
Authors: Zhou Shuqin , Li Shaoyi , Bai Huadong 
Published: February 2011

Abstract
Acrylonitrile-butadiene rubber (NBR) in latex form was selectively hydrogenated by redox system consisting of hydrazine hydrate and hydrogen peroxide, with boric acid as catalyst. Soluble hydrogenated NBR latex was obtained; but the coagulated products were gelled on drying. This problem becomes the major obstacle for the hydrogenation technique to be commercialized. It is important to study the crosslinking reaction in the system and to solve the problem. The cause for the crosslink was investigated in three possibilities: (i) crosslinking caused by the hydrogenation of CN group; (ii) by the oxidation of C=C double bonds and (iii) by radicals in the system. The control of the crosslink was also studied. The oil resistant nitrile group —CN on the polymer chain had no change during drying process. There were no signs of carbonyl group C=O formed by oxidation and amine like groups -NH- formed by the hydrogenation of CN in HNBR gel fraction. The newly formed alkoxyl radicals were detected by ESR spectroscopy analysis in the hydrogenation system after specific reaction time. Crosslinking reaction was controlled to a large extent by using hydroquinone as gel inhibitor.
Protein Levels Affect the Cure Efficiency and Allergenic Potential of Polyisoprene Latices
Authors: Schloman W. W. , Teetor V. H. , Ray D. T. 
Published: February 2011

Abstract
Commercial NR latex has a higher total protein content than guayule (GR) latex. Some NR proteins are allergens bound to the rubber particle surface. Washing NR latex with a non-ionic surfactant displaced these particle-bound proteins and reduced allergens by more than 95%. The cost of such deproteination was reduced vulcanization efficiency, as determined by crosslink density. The extent of vulcanization correlated well with both total protein and allergen levels. Compared with films prepared from untreated NR latex, films from both surfactant-treated NR latex and GR latex had lower states of cure. Where particle-bound proteins were still present, as they are in GR latex, crosslink development could be completed by heat aging. In contrast, crosslink development in the film from surfactant-treated NR was complete after dipping and drying. The resulting films yielded high levels of extractable protein allergens.
New Concept of Co-Agents for Scorch Delay and Property Improvement in Peroxide Vulcanization
Authors: Grima M. M. Alvarez , Talma A. G. , Datta R. N. , Noordermeer J. W. M. 
Published: February 2011

Abstract
Peroxide cure is an important and widely used cure system for rubber. Several properties obtained via peroxide vulcanization are superior and not achievable with sulfur vulcanization, e.g.: aging resistance, no reversion and low compression set. However, other properties such as tensile strength and dynamic properties, are inferior to those of sulfur vulcanizates. The use of co-agents in peroxide cure leads to a certain extent to improvement in mechanical properties such as tensile strength. Nevertheless the properties are still inferior with respect to mechanical/dynamical properties of sulfur-cured articles. If these properties can be improved, the range of applications of peroxide cure in the rubber industry can be significantly broadened. Scorch is a common problem in peroxide cure, especially for injection molding and extrusion applications. Several additives can help to improve scorch safety, however, they always result in a lower peroxide efficiency, thus inferior vulcanizate properties. In the present study a new concept of co-agents for peroxide vulcanization is introduced. This new concept consists of the use of a combination of a bismaleimide type co-agent, like N,N′-m-phenylenedimaleimide (BMI-MP), and a sulfur containing compound, like dipentamethylenethiuram tetrasulfide (DPTT). This combination provides scorch safety and at the same time improves the mechanical properties of the vulcanizates. Within the bismaleimide type co-agents N,N′-p-phenylenedimaleimide (BMI-PP) provides better mechanical properties than BMI-MP. The concentration of co-agent and sulfur containing compound have a big influence on the scorch time and on the mechanical properties. Optimal properties are reached with 4 phr of co-agent and 0.7 to 0.96 phr of sulfur containing compound.
Preparation and Characterization of Radiopaque Natural Rubber
Authors: Nisha V. S. , Joseph Rani 
Published: February 2011

Abstract
Currently radiopaque polymers are of great interest to medicine and dentistry because of their wide area of applications such as catheters, surgical tools, dental products, radiation shielders etc. Lead has historically been used as the shielding material, but not without health and environmental concerns. In this work, we have prepared radiopaque materials from natural rubber (NR) through different routes. Natural rubber was iodinated and characterized using UV-VIS spectroscopy, thermo gravimetric analysis and clinical X-ray techniques. The physical properties of Iodinated NR compounds prepared at ambient and high temperatures were studied. The low temperature cured samples showed better radiopacity and conductivity than high temperature cured samples. Radiopaque NR was prepared using radiopacifiers like barytes, barium sulphate, zinc oxide and active zinc oxide. The physical properties of the NR vulcanizates with different radiopacifiers were studied. Clinical X-ray techniques have been used to confirm the radiopacity. The optical density of the samples were measured and compared with that of conventionally used lead shield.
Characterization of Adhesion Interlayer Between Rubber and Brass by a Novel Method of Sample Preparation
Authors: Hotaka Takeshi , Ishikawa Yasuhiro , Mori Kunio 
Published: February 2011

Abstract
Instrumental characterization of an adhesion interface in a rubber-brass system often faces a difficulty in exposing a clean surface due to a stick of rubber residue on a brass surface. We have succeeded in isolating an interface from the rubber matrix by inserting a filter paper between rubber and brass during the vulcanization. Clean interface was obtained by removing the filter paper after the vulcanization, enabling a detailed characterization of the interface by XPS and SEM-EDX from a practical rubber formulation. Formulation of cobalt naphthenate did not contribute to a formation of adhesion interlayer in an initial stage of cure, but greatly affected the composition of copper sulfide during the vulcanization. It was found that a dosage of cobalt improved a growth of interface at aging. Copper sulfide particles were found to be spherical at the interface for unaged specimens. It was revealed that excess growth of copper sulfide was a main feature at a humidity aging, while the growth of zinc oxide was eminent under a hot water aging. Scheme of an aging reaction was considered to depend on an interaction between brass and external factors such as heat, water, and oxygen.
International Rubber Science Hall of Fame Inductee
Authors: Holden Geoff 
Published: February 2011

Abstract
Citation* - American scientist, chemist. Dr. Ralph Milkovich was a pioneer in anionic polymerization and heterophase polymer science. He demonstrated the concept of living anionic polymerization. He prepared the first poly(styrene-block-isoprene-block-styrene) thermoplastic elastomer, exhibiting the properties of a vulcanized rubber but processible as a thermoplastic. He also prepared a new class of polymeric materials, macromonomers, useful for the syntheses of well-defined, comb-type graft copolymers.
Equi-Biaxial Fatigue of Elastomers: The Effect of Oil Swelling on Fatigue Life
Authors: Jerrams Steve , Hanley John , Murphy Niall , Ali Hassan 
Published: February 2011

Abstract
The effect of oil swelling on the fatigue life of ethylene propylene diene monomer rubber (EPDM) has been studied under conditions of equi-biaxial cycling using dynamic bubble inflation. Specimens were subjected to varying degrees of swelling in reference mineral oils and fatigued at constant engineering stress amplitudes. The reference oils used for swelling the EPDM had known aniline points, allowing the rubber-oil compatibility to be determined. The inflation fluid for fatigue testing was selected with a solubility parameter that would produce a desired level of incompatibility with the test specimens, thereby limiting the amount of additional swelling during cycling. Wöhler (S-N) plots were generated for dry and swollen specimens and the changes in complex elastic modulus E* and dynamic stored energy were analyzed. Specimen fractures were analyzed using scanning electron microscopy. The fractures in the swollen samples show that the failure surfaces flowed more readily over each other than did those of the dryer specimens.
Reactive Compatibilization of Recycled Polyethylenes and Scrap Rubber in Thermoplastic Elastomers: Chemical and Radiation-Chemical Approach
Authors: Grigoryeva O. , Fainleib A. , Grenet J. , Saiter J. M. 
Published: February 2011

Abstract
Reactive compatibilization of recycled low- or high-density polyethylenes (LDPE and HDPE, respectively) and ground tire rubber (GTR) via chemical interactions of pre-functionalized components in their blend interface has been carried out. Polyethylene component was functionalized with maleic anhydride (MAH); as well, the rubber component was modified via functionalization with MAH or acrylamide (AAm) using chemically or irradiation (γ-rays) induced grafting techniques. The grafting degree and molecular mass distribution of the functionalized polymers have been measured via FTIR and Size Exclusion Chromatography (SEC) analyses, respectively. Additional coupling agents such as p-phenylene diamine (PDA) and polyamide fiber were used for producing some thermoplastic elastomer (TPE). Thermoplastic elastomer materials based on synthesized reactive polyethylenes and GTR as well as ethylene-propylenediene monomer rubber (EPDM) were prepared by dynamic vulcanization of the rubber phase inside thermoplastic (polyethylene) matrix and their phase structure, and main properties have been studied using DSC, DMTA and mechanical testing. As a result, high performance thermoplastic elastomers based on functionalized polyethylene and ground rubber with improved mechanical properties have been developed.
Filler Phase Distribution in Rubber Blends Characterized by Thermogravimetric Analysis of the Rubber-Filler Gel
Authors: Le H. H. , Ilisch S. , Kasaliwal G. R. , Radusch H-J. 
Published: February 2011

Abstract
The analysis of the rubber-filler gel of carbon black filled rubber compounds and blends provides useful information about the mixing process taking place inside the internal mixer. A new measure technique named wetting rate was introduced to describe the wetting behavior of the rubber onto the filler. Natural rubber (NR)/styrene-butadiene rubber (SBR) blends has been used for experimental investigation. NR shows a significantly higher wetting rate than SBR. The wetting rate does not only depend on the viscosity of rubber but strongly on the functionalization of it. Using the data determined from the thermogravimetric analysis (TGA) of rubber-filler gel, a new method was developed to characterize the kinetics of carbon black (CB) localization in the phases of heterogeneous rubber blends. During the first mixing stage, the CB localization is affected strongly by the wetting rate ratio of the blend components. In the second mixing stage, the rubber-filler interaction dominantly influences the distribution kinetics of the filler to the phases. Because of the higher wetting rate of the NR component, in the investigated NR/SBR blends more CB is found in the NR phase than in the SBR phase. The effect of the matrix viscosity and polarity on the phase specific CB distribution was systematically investigated.
Role of Compatibilization in Polymer Nanocomposites
Authors: Kroshefsky Robert D. , Price Jack L. , Mangaraj Duryodhan 
Published: February 2011

Abstract
Polymeric nanocomposites based on nanoclay, nanosilica, carbon nanotubes, and ceramic or mineral nanoparticles have been developed for a variety of applications. The large surface-to-mass ratios of these particles require good adsorption of the polymeric material on the particle surface to provide the adhesion levels between the filler and matrix resin necessary for improved performance. We review the basic principles underlying these surface interactions and their application in the preparation of a variety of these nanocomposites, as well as in explaining their performance. We demonstrate that the principles underlying the compatibilization of polymer blends and alloys can be successfully used to design nanocomposites and understand their performance.