bluuebunny/crossref_metadata_2025_split huggingface dataset:
Goodyear Medalist Lecture. Rubber Friction and its Relation to Tire Traction
Authors: Grosch K. A. 
Published: February 2011

Abstract
Rubber friction differs from that of hard solid materials in that it is not linearly related to the normal load and it depends strongly on sliding speed and temperature. There exists an interrelation between these two variables on their effect on the friction coefficient, first observed for the viscosity of liquids and generally described by the universal WLF transformation equation. The friction coefficient at a constant load is then described by a so-called master curve. Such master curves have been obtained on different types of surface and for gum rubbers as well as filled rubbers on wet and dry surfaces and it is shown that they may also be obtained on ice. The shape of the curve and position on the log(aTv) axis depends on the polymer and the track surface structure indicating that two distinct processes determine the friction: adhesion friction akin to a molecular relaxation process and a deformation process in which energy is lost due to the cyclic deformation of the rubber by the surface asperity. To obtain such a master curve it is necessary to keep the experimental speeds so low that the temperature rise in the contact area can be neglected. In practical tire tests, sliding speeds are high and hence the temperature rises with speed. Since the WLF equation is a negative function of temperature, the range of log(aTv) is limited. If thermocouples are used as sliders on rubber, it is shown that the experimental curves as function of speed can be transformed into a part of a master curve. For compound development friction tests, a limited range of track temperatures and speeds are sufficient to ensure a high correlation with road test data. A single point laboratory measurement may correlate with road tests if carefully chosen. More usually, it leads to misleading conclusions. Side force measurements at a reasonably large slip angle also reflect the friction coefficient and are a useful laboratory tool to evaluate the traction properties of tread compounds.
Thermoplastic Elastomers Based on PP/EPDM Blends by Dynamic Vulcanization
Authors: Naskar Kinsuk 
Published: February 2011

Abstract
This review article introduces various aspects of dynamic vulcanization as applied to thermoplastic elastomers (TPEs). The classification of polymer blends and TPEs, the development of thermoplastic vulcanizates (TPVs), and the application of different types of crosslinking systems with special emphasis on peroxides/co-agents, and phenolic resins as crosslinking agents for polypropylene / ethylene propylene diene rubber (PP/EPDM) blends are primarily reviewed. The morphology and rheology of these TPVs are also touched upon.
Elastomers - An Engineering Material
Authors: Hertz Daniel L. 
Published: February 2011

Abstract
Elastomers are engineering materials. Defined as nonlinear viscoelastic solids; applications are normally deformations under twenty five (25) percent. Conventional engineering values of shear modulus G and Young's modulus E can be determined in this relatively linear section of the stress-strain relationships. The viscoelastic description indicates a time/temperature relation response. Treloar notes that G is both the shear modulus value and the elastic constant. The high bulk modulus allows us to assume E=3G thus we have several approaches to develop G and utilize the equation G=NκT=ρRT/Mc, (hereby ρ is density, R gas constant, Mc average chain molecular weight, T temperature Kelvin). This allows us to monitor aging by changes in Mc that occur due to network aging. The aging process will be monitored by strain energy density changes, compressive stress-relaxation (CSR) and dynamic mechanical rheologic testing (DMRT)
Development and Properties of Novel Thermoplastic Elastomer Based on Poly (Phenylene Ether)
Authors: Gupta Samik , Krishnamurthy Raja , Preschilla Nisha , Biswas Amit , Bhowmick Anil K. 
Published: February 2011

Abstract
A series of novel thermoplastic elastomers (TPEs) based on poly (phenylene ether)(PPE), which is an engineering thermoplastic with a glass transition temperature &gt;200 °C, has been developed. The resulting blend based on PPE, Polystyrene (PS), Ethylene Vinyl Acetate (EVA) and a tri-block copolymer, Styrene-Ethylene-Butylene-Styrene (SEBS), met all the key performance criteria for thermoplastic elastomers in terms of melt processability, tensile elongation, tension set and recyclability. Depending on Flory's interaction parameter and critical surface tension value, the elastomeric components of the blends were selected. Morphological analysis of the blend using Transmission Electron Microscopy indicated a unique microstructure, wherein EVA domains were dispersed in a mainly co-continuous matrix comprising of the blend of PPE-PS/SEBS. Differential Scanning Calorimeter and Dynamic Mechanical Analysis were done to evaluate the thermal transitions of the blend and to throw light on the interactions between the various components of the blend. Thermogravimetric analysis indicated that PPE played a critical role by increasing the temperature of the onset of degradation of the blend. A comprehensive study of the structure-property correlations of this unique blend has been undertaken.
Highly-Purified Natural Rubber by Saponification of Latex: Analysis of Residual Proteins in Saponified Natural Rubber
Authors: Yunyongwattanakorn Jintana , Tanaka Yasuyuki , Sakdapipanich Jitladda , Wongsasutthikul Voratep 
Published: February 2011

Abstract
Highly purified natural rubber (NR) was prepared by saponification of fresh latex (FL-latex) and preserved high-ammonia latex (HA-latex) in the presence of surfactant to reduce the residual proteins in resulting solid NR. Saponification of latex diluted to 30% DRC was carried out with 1–7% (w/v) sodium hydroxide at room temperature for 1–7 hr at 70 °C and coagulated with formic acid. The nitrogen content of NR obtained by coagulation of the saponified latex markedly decreased to less than 0.014% by centrifugation of the saponified latex or soaking the coagulum in aqueous sodium hydroxide solution. The nitrogenous compounds from saponified NR (SAP-NR) were extracted with sodium dodecyl sulphate (SDS) aqueous solution and subjected to SDS-Polyacrylamide Gel Electrophoresis (SDS-PAGE) analysis to check the molecular weight of extracts. The extract from SAP-NR and deproteinized NR by protease (DPNR) for comparison was subjected to the analysis of allergic protein by FIT Kit method, based on Enzyme-Linked Immunosorbent Assay (ELISA) method. No extractable protein was observed in SAP-NR, whereas DPNR contained 1.5 μg/ml proteins. The results from SDS-PAGE analysis and FIT Kit test demonstrated that NR free from allergic proteins is obtainable by saponification of FL-latex with 1.5% NaOH at 70 °C for 1 hr or at room temperature for 24 hr.
Manufacture of Thermoplastic Elastomer Tubes by Water Assisted Injection Molding Technology
Authors: Liu Shih-Jung , Lin Kun-Yeh , Liu Che-Chi 
Published: February 2011

Abstract
The objective of this study was to manufacture thermoplastic elastomer tubes by a novel water assisted injection molding technology and to experimentally investigate the effects of various processing parameters on the molded parts quality. Styrene-ethylene/butylene-styrene (SEBS) compounds based thermoplastic elastomers were used for all the experiments. Experiments were carried out on a lab-developed water assisted injection-molding system, which included a water pump, a water injection pin, a water tank equipped with a temperature regulator, a pressure accumulator, and a control circuit. A porous type water injection pin was designed and made to mold the parts. After molding, the lengths of water penetration as well as the hollowed core ratios in molded tubes were measured. The effects of different processing parameters on the hollowed core ratios were determined. It was found that the melt temperature and water injection delay time were the principal factors influencing the water penetration behaviors. In addition, a comparison has been made between the parts molded by water assisted injection molding and gas assisted injection molding. The results suggest that water assisted injection molded parts mold parts with less residual wall thickness distributions along the channel. However, thermoplastic elastomers molded by water exhibited higher wall thickness difference at curve sections than those molded by gas.
Anionic Synthesis of Trialkoxysilyl-Functionalized Polymers
Authors: Quirk Roderic P. , Ocampo Manuela , King Rebecca L. , Polce Michael J. , Wesdemiotis Chrys 
Published: February 2011

Abstract
A new general functionalization methodology (GFM) is applied to the synthesis of trimethoxysilyl-functionalized polymers. This GFM involves (a) the preparation of a well-defined polymeric organolithium compound (PLi) using alkyllithium-initiated anionic polymerization; (b) quantitative silyl hydride-functionalization of PLi with chlorodimethylsilane to form PSi(CH3)2H; (c) hydrosilation of PSi(CH3)2H with vinyltrimethoxysilane in the presence of Karstedt's catalyst. The desired PSi(OCH3)3 was obtained in &gt; 80% yield. The product was characterized by SEC, 1H and 13C NMR and MALDI-TOF mass spectrometry.
A Comparative Investigation of Surface Modification of Carbon Black and Silica by Plasma Polymerization
Authors: Mathew T. , Datta R. N. , Dierkes W. K. , Noordermeer J. W. M. , van Ooij W. J. 
Published: February 2011

Abstract
Carbon black and silica are widely used active fillers in the rubber industry to improve the physical and dynamic properties of rubbers. The surface energy difference between rubbers and these active fillers is large, which has a negative influence on the stability of their dispersion in the rubber matrix and on the distribution in blends of different rubbers. Reduction of the surface energy of carbon black and silica is aimed for by modifying their surfaces. Plasma polymerization is utilized to modify the surface of carbon black and silica by depositing a thin film over its surface. The modified fillers are characterized using thermogravimetric analysis (TGA), x-ray photoelectron spectroscopy (XPS) and time of flight secondary ion mass spectroscopy (ToF-SIMS). The studies show that carbon black and silica behave differently towards surface modification by plasma polymerization. The difference in behavior of carbon black and silica is related to the availability of active sites on their surface during exposure to the plasma atmosphere. In this paper the mechanistic aspects of surface modification by plasma polymerization are also discussed.
The Application of High Resolution Chemical Imaging Techniques for Butyl Rubber Blends
Authors: Winesett Donald A. , Tsou Andy H. 
Published: February 2011

Abstract
Atomic Force Microscopy (AFM), Time-of-Flight Secondary Ion Mass Spectrometry (ToF-SIMS) imaging, and Scanning Transmission X-ray Microscopy (STXM) are applied to identical series of elastomeric blends to evaluate the relative strengths and weaknesses of each imaging technique. AFM is a high resolution, high contrast technique with straight forward sample preparation that derives contrast through elastic modulus variations, but, when used in a conventional mode, has limited chemical specificity. ToF-SIMS imaging can map phases, detect trace levels (ppm) of additives and other chemical species based on relatively straight forward sample preparation, but has poorer spatial resolution and the instrumentation is expensive. STXM has excellent chemical specificity and good spatial resolution but is only available at a beamline and requires more advanced sample preparation. Each technique will be overviewed briefly and relative merits of each will be compared based on evaluations of some commercially relevant rubber blend materials.
Analysis of Stress-Strain Data for Dry and Swollen Rubbers by a New Tube Model of Rubber Elasticity Based on Finite Chain Extensibility
Authors: Hoei Yoshio 
Published: February 2011

Abstract
New stress-strain equations have been extensively tested for both unswollen and swollen rubbers, which were very recently derived from a new non-Gaussian tube model of rubber elasticity that incorporates the effect of finite chain extensibility. Particularly, as core parameters, they involve the junction-fluctuation suppression parameter (h) of Dossin and Grassley and the tube deformation index (γ) of Gaylord. The best-fits of the equations to experimental literature data for unswollen and swollen networks have been done. The results are very good with sufficiently small departures of theory from experiment and the two fitting parameters can consistently well explain the molecular situations of the networks.
Rubber Oxidation and Tire Aging - A Review
Authors: Baldwin John M. , Bauer David R. 
Published: February 2011

Abstract
While a new tire may have excellent resistance to crack initiation and propagation between the steel belts, an aged tire of the exact same construction can exhibit dramatically reduced crack growth resistance, which in some cases may contribute to tire failure. This article will review the research that has gone into quantifying the rate of oxidation the steel belt rubber oxidizes in different climates from tire samples retrieved from consumers' vehicles. The information obtained from the field is then compared to data collected from various resources attempting to develop accelerated tire aging protocols. Finally, methods for potentially improving tire aging are reviewed.
Atomic Force Microscopy (AFM) for Rubber
Authors: Johnson Lili L. 
Published: February 2011

Abstract
In this review, first, the development of atomic force microscopy as an imaging technique, as a surface force apparatus, and as a nanoindenter was illustrated using experimental studies. The experimental analysis of atomic force microscopy emphasizes the empirical methods of achieving high resolution imaging through controlled forces between tip and sample interactions. Second, mapping mechanical properties on nanometer scale by atomic force microscopy is presented with both experimental investigations and selection of elastic models. Elastomer crosslink density was mapped using atomic force microscopy combined with elastic theories. The force — penetration depth investigation of crosslink density for elastomer by AFM shows linear correction with both experimental studies using Dynamic Mechanical Thermal Analysis (DMTA) and classic swelling method and calculation using statistical rubber elasticity theory. Last, the focus is on the understanding of atomic force microscopy for practical applications. Filler dispersion and blends structure are demonstrated for automotive applications. Micro phase separation was intensely studied for film industries. Morphology of composites is investigated for the applications of tire, automotive and foaming industries.
Rubber Abrasion and Tire Wear
Authors: Grosch K. A. 
Published: February 2011

Abstract
Rubber abrasion is essentially a mechanical tearing process and has been linked with the rate of a cut growth process as function of the tearing energy dissipated in the contact area between rubber and track which leads inevitably to considerable temperature rises at the points of highest stress concentration i.e. at the points at which a mechanical detachment of abraded particles is most likely. This leads to thermal degradation and oxidation as important secondary mechanisms which may well decide whether a compound performs better or worse than a reference outweighing the mechanical properties. A laboratory method has been developed, using the LAT 100 test equipment, which uses the energy dissipation and slip speeds in the contact area of a rubber sample wheel, rotating under slip, to evaluate the abrasion performance of a compound over a wide range of these variables. The resulting equations can be used either to test directly the correlation between laboratory and road test results which is usually good over a limited range, or they are used in a road test simulation program with well defined road test conditions. The latter gives a set of single compound ratings and tire lives. These depend however strongly on the chosen test conditions and in that they reflect reality
Effect of Fillers on Wet Skid Resistance of Tires. Part II: Experimental Observations on Effect of Filler-Elastomer Interactions on Water Lubrication
Authors: Wang Meng-Jiao , Kutsovsky Yakov 
Published: February 2011

Abstract
It was demonstrated previously that on the worn surface of vulcanizates during wet skid tests, carbon black is covered by rubber whereas silica particles are at least partly exposed. In this report, the experimental results of the effects of carbon black and silica on wet skid resistance measured by various test methods and under different conditions are explained based on the “Three Zone Concept” of the contact area of tread compounds with the track surface during sliding or rolling. The three zones are water film squeezing, transition and traction zones. In the first two zones, where hydro-dynamic and micro-elastohydrodynamic lubrication mechanisms are dominant, silica is beneficial for wet friction. In the traction zone, where friction is governed by boundary lubrication, carbon black is preferred. Under test conditions where the water squeezing and transition zones are more developed, such as at high speed, lower temperature, smoother track surface, lower load, higher slip angle, and ABS brake, the silica shows better performance, but otherwise where the traction zone is larger, carbon black gives higher wet skid resistance. Accordingly, a new carbon-silica dual phase filler CSDPF 4210 that is characterized by high surface coverage with silica has been developed. With this material, the wet skid resistance of a passenger tire on a car with ABS at high speed and smooth road surface is significantly improved.
Alkylphenol Disulfide Polymer Accelerators and the Vulcanization of Isobutylene Based Elastomers
Authors: Rodgers Brendan , Solis Scott , Tambe Nitin , Sharma Bharat B. 
Published: February 2011

Abstract
Vulcanization of isobutylene/isoprene copolymer (butyl rubber) using sulfur and organic accelerators is facilitated by the presence of the carbon-carbon double bond in the copolymer isoprenyl unit. The low number of unsaturated monomer units, usually in the order of 2%, has traditionally necessitated use of ultra-fast accelerators such as tetramethyl thiuram disulfide (TMTD) or zinc dimethyldithiocarbamate (ZMDC). Use of such accelerators can result in formation of nitrosamines which may be undesirable. There are a number of alternatives to thiuram and dithiocarbamate cure systems such as use of xanthates and phosphate based accelerators. Alkylphenol disulfide based accelerators also enable attainment of favorable properties when used in butyl and halobutyl compounds. Use of alkylphenol disulfide accelerators in butyl rubber compounds can allow improvement in reversion resistance, adhesion to natural rubber tire casing compounds, and aged property retention. In bromobutyl compounds containing alkylphenol disulfide accelerators in binary (two accelerators) or tertiary (three accelerators) cure systems, adjustment in cure rate to meet specific requirements and aged property retention is possible. This, fifth in a series of studies on the vulcanization of isobutylene elastomers, explores the use of alkylphenol disulfide cure systems for vulcanization of both butyl and bromobutyl rubbers and is intended to provide a starting point for further development work.
Strain-Induced Crystallization of Natural Rubber: Effect of Proteins and Phospholipids
Authors: Amnuaypornsri Sureerut , Sakdapipanich Jitladda , Toki Shigeyuki , Hsiao Benjamin S. , Ichikawa Naoya , Tanaka Yasuyuki 
Published: February 2011

Abstract
The effects of proteins and phospholipids in natural rubber (NR) on the strain-induced crystallization behavior during uniaxial deformation were studied by in-situ synchrotron wide-angle X-ray diffraction (WAXD) technique and simultaneous measurements of stress-strain relation. The influences of proteins and phospholipids in NR were evaluated separately by decomposition methods using deproteinization and lipase treatment, respectively. It was found that both components form a naturally occurring network, which is responsible for the strain-induced crystallizability of unvulcanized NR and the corresponding high mechanical property. This network also plays a significant role in strain-induced crystallization of vulcanized natural rubber.
Influence of Different Nanofillers and their Dispersion Methods on the Properties of Natural Rubber Nanocomposites
Authors: Bhattacharya Mithun , Maiti Madhuchhanda , Bhowmick Anil K. 
Published: February 2011

Abstract
The effects of varying morphological and chemical constitution of nanofillers and various dispersion methods on natural rubber nanocomposites prepared by conventional processing techniques were determined by incorporating various nanofillers like montmorillonite, sepiolite (SP), hectorite, carbon nanofiber (F) and expanded graphite. When compared with the gum, SP filled (4 phr) nanocomposite exhibited an increment of 26% in the modulus and F (6phr) increased the tear strength by 18%, over the gum. Nanofiller dispersion was enhanced by various compatibilization and dispersion techniques which helped SP introduce 56 and F 113% increment in the modulus of the nanocomposites, over the gum rubber vulcanizate. It also rendered 28% improvement in the tear strength of F filled system. Deeper insights into the material properties were obtained through dynamic mechanical and swelling studies. Property-morphology correlation of the hybrids was performed through X-ray Diffraction, Atomic Force Microscopy and Transmission Electron Microscopy. Surface energy (SE) studies exhibited that the higher surface energy of SP (38 mJ/m2) and F (44 mJ/m2) than the rubber (35 mJ/m2) ensured necessary wetting and hence was responsible for improvement of the properties. Using SE, cleavage energy and work of adhesion data, a new mechanism based on adsorption followed by shear of polymer-bound nanofillers was suggested.
Improved Aging Performance of Virgin EPDM Roof-Sheeting Compounds with Amine-Devulcanized EPDM Weatherstrip Material
Authors: Dijkhuis K. A. J. , Dierkes W. K. , Noordermeer J. W. M. , Sutanto P. 
Published: February 2011

Abstract
Sulfur-cured EPDM building-profile material was reclaimed in a co-rotating twin-screw extruder using hexadecylamine as reclaiming aid. This reclaim was blended with increasing amounts of a virgin EPDM roof-sheeting masterbatch and cured at temperatures allowing for a reversion-free vulcanization. The trends in cure characteristics showed that increasing amounts of reclaim employed in the blends lowered the reversion-free cure temperature and the maximum torque values, while the vulcanization speed was increased. The insoluble fraction and crosslink density both decreased, while the ratio of mono- to di- and polysulfidic crosslinks increased with growing reclaim contents. A SEM-EDX morphology study of the blends, in order to evaluate the dispersion of the reclaim into the virgin rubber matrix showed, that even large amounts of reclaimed material resulted in homogeneous and smooth compounds. Tensile strength, modulus at 300% strain and hardness decreased, while elongation at break, tear strength and compression set at 70 °C increased with increasing reclaim ratios. Irrespective of the blend ratios, the mechanical properties all fulfilled the most stringent UEAtc specifications for EPDM roof-sheeting. Increasing reclaim contents improve the aging resistance and prolong the time before a practical limiting value for elongation at break of 250% for EPDM roof-sheeting purposes is reached.