bluuebunny/crossref_metadata_2025_split huggingface dataset:
Microdispersion of Carbon Blacks in Rubber, Part I: Some Quantitative Aspects by AFM Image Analysis
Authors: Wang C. C. , Wu S. H. , Donnet J. B. , Wang T. K. 
Published: February 2011

Abstract
The microdispersion state of carbon blacks in an emulsion SBR matrix has been observed by atomic force microscopy (AFM) and the images analyzed quantitatively. The fillers were well dispersed in the rubber samples. Different parameters, such as the surface fraction of fillers in images, particle size distance distributions, have been extracted and the main results are presented.
Tire-Cord Adhesion: How the Source of Zinc Can Influence the Structure of the Bonding Interface
Authors: Fulton W. Stephen 
Published: February 2011

Abstract
Many excellent, fundamental studies on tire cord adhesion have described how zinc diffuses through the rubber brass interface to be sulphidized to form zinc sulphide and how zinc combines with oxygen to create zinc oxide during dezincification. The source of zinc is assumed primarily to originate in the brass of the tire cord. However, studies using isotope-depleted zinc oxide in the rubber formulation are presented here which reveal how zinc from different sources is distributed within the bonding interface, before and after aging. To differentiate between two sources of zinc, i.e. brass and compound, zinc oxide made from 64Zn-depleted zinc was mixed in the formulation and Secondary Ion Mass Spectroscopy (SIMS) depth profiling was used to follow the zinc isotope ratios within the interfacial layers. As the relative ratios of the various zinc isotopes changed during depth profiling, the contribution of zinc from each source could be determined. Profiles were obtained for unaged, heat-aged and humidity-aged samples and in each case a relatively large amount of zinc that originated in the rubber compound was shown to be incorporated as zinc sulphide during the thickening of the interfacial layer. Heat-ageing produced a thickened dendritic structure that was visualized in Transmission Electron Microscopy (TEM) using a sample prepared by focussed ion beam (FIB) techniques. This study was complemented by Energy Dispersive X-Ray (EDX) analysis, producing elemental linescans to illustrate more fully the role of zinc during the thickening of the bonding interface.
Effects of Cure Systems of Ground Rubber and Rubber Matrix on their Adhesion and Crosslink Structures
Authors: Kim S. W. , Park H. Y. , Seo K. H. 
Published: February 2011

Abstract
There has been a great deal of research on the effects of ground rubber (GR) on the cure characteristics of GR-filled rubber compounds. It has been known that the cure systems of the rubber matrix and GR also had an effect on the cure characteristics and physical properties of GR-filled compounds. In this study, the variation of the crosslink density and crosslink types of recured vulcanizates and fresh vulcanizates, with respect to the cure systems, were investigated by using a three-layered model. In addition, the adhesion forces between recured vulcanizates and fresh vulcanizates were measured, and the fracture surfaces were examined. Depending on the cure systems, the changes in the crosslink density and crosslink types of recured and fresh vulcanizates varied significantly and the failure modes of adhesion specimens were also different.
Nanoscale Rubber Reinforcement: A Route to Enhanced Intercalation in Rubber-Silicate Nanocomposites
Authors: Al-Yamani Faisal , Goettler Lloyd A. 
Published: February 2011

Abstract
Addition of organo-modified layered silicates (e.g., montmorillonite clay) to polymer matrices can produce effective polymer nanocomposites by intercalation of macromolecules into the interlayer galleries. Flexible rubber nanocomposites represent an untapped application of this technology that is still in an early stage of development. This research focuses on the enhancement of rubber matrices through the incorporation of different types of layered silicates along with a dispersion agent, hexamethoxymethylmelamine (HMMM). Styrene-co-butadiene rubber (SBR) and acrylonitrile-co-butadiene rubber (NBR) nanocomposites were prepared via a straightforward rubber compounding process and investigated through wide angle x-ray diffraction to determine the resulting clay morphology. The mechanical evaluation of the rubber nanocomposites was by tensile and tear testing. The dispersing agent affected both the morphology, registered as an increase in the gallery height, and mechanical properties, which showed significant additional reinforcement with the optimal combination of organoclay and rubber type. This work thus demonstrates the positive benefit of such a dispersion agent.
Reactive Blending, Reinforcement and Curing of NR/BR/EPDM Compounds for Tire Sidewall Applications
Authors: Sahakaro K. , Naskar N. , Datta R. N. , Noordermeer J. W. M. 
Published: February 2011

Abstract
Tire sidewall compounds are generally formulated using NR and BR to achieve the required dynamical properties. The most widely used antiozonant, N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine (6PPD), is a staining, toxic and environmentally unfriendly substance. Incorporation of EPDM into NR/BR blends improves ozone resistance, but leads to poor properties because of differences in filler affinity and cure incompatibility of the rubber components. In this work, the cure incompatibility is overcome by utilizing a reactive processing technique, making use of the most commonly used accelerator CBS and sulfur. The entire amount of curatives is first added into the EPDM. After a thermal pretreatment step related to the scorch time of the EPDM, the modified EPDM is mixed with pre-blended NR/BR. The reactive blends show significant improvements of physical properties in comparison with those of conventional straight mixes, due to improvement of the crosslink and carbon black distributions, confirmed by AFM and TEM images. The physical properties of the reactive mixed NR/BR/EPDM blends are equivalent or even superior to regular filled NR/BR blends for tire sidewall applications. The blend with 30 phr of EPDM has excellent ozone resistance while 6PPD can be totally omitted from the formulation.
Environmental Friendly Surface Treatment of SBS Rubber with Acidified Chloramine T Aqueous Solutions
Authors: Navarro-Bañón M. Virtudes , Pastor-Blas M. Mercedes , Martín-Martínez José Miguel 
Published: February 2011

Abstract
As environmental friendly alternative to the halogenation treatment with trichloro isocyanuric acid solutions in organic solvents (TCI/MEK), in this study a water-based surface treatment for rubber materials based in chloramine T aqueous solutions has been proposed. It was found that the effectiveness of chloramine T (CT) (N-chloro-sodium-p-toluenesulphenamide) as chlorinating agent for rubber depends on the pH of the chlorinating solution. The surface modifications and adhesion in one SBS rubber treated with aqueous solutions of CT has been studied. Acidification of CT aqueous solutions produced the formation of dichloramine T (DCT) and hypochlorous acid (HClO), species which reacted with C = C bonds of the butadiene units. A decrease in the pH of the CT aqueous solutions produced more extended surface modifications and improved adhesion properties in the joints produced with chlorinated SBS rubber and waterborne polyurethane adhesive. T-peel strength values obtained were slightly lower than those obtained for the SBS rubber surface treated with the organic solvent chlorinating system (TCI/MEK). The solvent effect leading to local swelling and therefore to deeper modifications in the rubber near surface properties was not present with water based solutions, and then, the modifications were much more superficial. On the other hand, acidification with hydrochloric acid produces deposition of NaCl crystals on the SBS rubber surface. Thus, acidification of the chloramines T solution with sulfuric acid was preferable.
Scanning Transmission X-Ray Microscopy of Curative and Filler Migration of Inner Liner Compounds
Authors: Winesett D. A. , Tsou A. H. 
Published: February 2011

Abstract
Materials of significance in the rubber industry generally consist of a complex blend of elastomers, fillers, curing agents and other additives. Elucidating the complex microstructure-to-property relationship of these materials is essential for optimal product development. This requires characterization techniques that are capable to differentiate, map, and quantify these similar materials with sufficiently high spatial resolution. A technique that can provide such chemical microspeciation is Scanning Transmission X-ray Microscopy (STXM). STXM is a beamline based microscopy that utilizes the chemical specificity of Near Edge X-ray Absorption Fine Structure (NEXAFS) combined with zone plate optics to achieve high spatial resolution (&lt; 50 nm) and low beam damage to allow the successful characterization of multi-component materials that would be difficult or impossible with other techniques. A brief introduction to the technique will be presented along with example applications showing curative and filler distribution mapping in multi-component elastomeric systems.
Influence of some Non-Rubber Components on Aging Behavior of Purified Natural Rubber
Authors: Tuampoemsab Surakit , Sakdapipanich Jitladda , Tanaka Yasuyuki 
Published: February 2011

Abstract
Skim rubber (SR) was obtained by coagulation of the serum phase separated in the course of preparation of concentrated natural rubber (NR) latex. Saponified skim rubber (SSR) was prepared by soaking of SR with aqueous sodium hydroxide. The effect of non-rubber components on the thermal oxidative degradation of SSR was analyzed under mild and heating conditions for SSR and deproteinized natural rubber (DPNR) as a model of purified NR. The effect of gel, ash, ester, nitrogenous and heavy metal on aging properties was analyzed for SSR and DPNR comparing with SR and NR coagulated from high ammoniated latex (HANR), respectively. SSR contained Cu ion of 37 ppm even after purification of SR by saponification, although other transition metal ions were not detected. The accelerated decomposition of SSR was presumed to be due to the activation of residual Cu ions as well as the decrease of nitrogenous substances acting as antioxidants after saponification. The effect of Cu ions was confirmed by heat-aging test at 140 °C for 150 min for DPNR mixed with Cu compounds such as [Cu(NH3)4]2+, CuSO4 and CuO. Butylated hydroxytoluene (BHT) was not effective to prevent the thermal oxidation of SSR samples, although it was effective for SR. This suggested the influence of residual Cu ion activated by treatment of SR with aqueous sodium hydroxide.
Application of NR-Based Latex Reclaim: The Link Between Structure and Properties
Authors: Dierkes W. K. , Rajan V. V. , Noordermeer J. W. M. , Joseph R. 
Published: February 2011

Abstract
Natural rubber based waste latex rubber (WLR) that is reclaimed with diphenyldisulphide by a thermo-mechanical process is blended with virgin rubber in different proportion to study the change in mechanical and viscoelastic properties. Two types of WLR differing mainly in the amount of polysulfidic linkages are reclaimed and blended with a virgin rubber compound with and without adjustment of the curing system, the former in order to compensate for the extra input of sulfur and accelerators due to the addition of reclaim. The cure behavior, final crosslink density and distribution, mechanical properties and dynamic viscoelastic properties of the blends with reclaimed WLR are compared to the property profile of the virgin material. The morphology of the blends as well as sulfur distribution between the matrix and the reclaim particle is analyzed. With increasing concentrations of WLR reclaim, tensile strength, tear strength and elongation at break decrease, whereas modulus at 100% elongation, compression set and hardness show an increase. The storage modulus of the vulcanized rubber blends decreases with increasing WLR reclaim content in the blend. Swelling measurements show that the crosslink density is reduced for the adjusted cure system but increased for a fixed cure system. These influences of reclaimed WLR on the property profile of a virgin compound will be discussed fundamentally in terms of morphology and crosslink distribution.
Fatigue Life Prediction for Elastomeric Structures
Authors: Mars W. V. 
Published: February 2011

Abstract
Elastomeric structures subjected to fluctuating loads can fail due to the nucleation and growth of cracks. To prevent such failures requires understanding of the physics underlying fatigue failure, approaches for characterizing material behavior, and methods for evaluating the effects of a given duty cycle. Duty cycles can be complex, often involving simultaneous loading in multiple directions, and non-periodic variations of the load. By considering how the loads applied to a structure are transformed into the experiences of individual cracks, a rational framework for predicting fatigue life can be developed.
Mechanistic Investigations into the Adhesion between RFL-Treated Cords and Rubber. Part I: The Influence of Rubber Curatives
Authors: Wennekes W. B. , Noordermeer J. W. M. , Datta R. N. 
Published: February 2011

Abstract
The adhesion between virgin textile cords and rubber is always weak, because of significant differences between fiber and rubber in modulus, elongation, polarity as well as reactivity. In order to improve the adhesion, it is customary to use adhesive systems, which act as bridges between elastomer and reinforcement. These are commonly based on Resorcinol/Formaldehyde/Latex (RFL) dips. For polyester and aramid fibers, two dip systems are applied. The first one is an epoxy pre-dip and the second dip is a RFL dip again. Although several mechanisms are proposed to explain the role of RFL, the majority of these explanations are based on assumptions rather than proper scientific investigations. In this paper an attempt is made to understand the role of the rubber vulcanization system on RFL-to-rubber bonding as judged by measuring the H-pullout force, Strap Peel Adhesion Force (SPAF) and the mechanical properties of the compounds. A positive correlation is found between the optimum cure time (t90) of the rubber compounds and the pullout and peel force. In literature this is commonly explained by the lack of curative migration from the rubber into the dip when t90 is low. In the present paper curative migration is monitored by scanning electron microscopy coupled to an energy dispersive X-ray spectrometer (SEM-EDX). A strong enrichment of curatives in the RFL dip near the interface is observed. A high accelerator loading results in a low t90 of the rubber compound as well as a more pronounced enrichment of curatives in the dip near the interface. Therefore the drop in adhesion does not occur because of lack of curative migration from rubber to the RFL layer, but more likely due to overcure of the latex in the dip, causing a brittle layer resulting in low pullout and peel strengths.
Mechanistic Investigations into the Adhesion between RFL-Treated Cords and Rubber. Part II: The Influence of the Vinyl-Pyridine Content of the RFL-Latex
Authors: Wennekes W. B. , Datta R. N. , Noordermeer J. W. M. 
Published: February 2011

Abstract
The adhesion between virgin textile cords and rubber is always weak, because of significant differences between fiber and rubber in modulus, elongation, polarity as well as reactivity. In order to improve the adhesion, it is common to use adhesive systems, which act as bridges between elastomer and reinforcement. These are commonly based on Resorcinol/Formaldehyde/Latex (RFL) dips. Despite the fact that this technique was invented in 1938 and no major improvements have been achieved since then, the mechanism by which the adhesion is obtained is still unclear. This paper contributes more fundamental understanding of RFL to rubber bonding. In previous work an enrichment of curatives at the RFL-rubber interface was observed by use of a Scanning Electron Microscope coupled to an Energy Dispersive X-ray spectrometer. In the present paper, the same method is used to determine the degree of enrichment for several RFL formulations, based on latices with varying vinyl-pyridine (VP) contents. The vinyl-pyridine content is varied by copolymerization of various VP terpolymers. Adhesion decreases with increasing vinyl-pyridine content for most rubber compounds. For aN NR compound with low accelerator content and a NR/SBR blend, an optimum vinyl-pyridine content of 10% is observed.
On Effective Modeling of Laminated Cord-Rubber Composites
Authors: Gurvich Mark R. 
Published: February 2011

Abstract
The major challenge in modeling of laminated cord-rubber composites (CRC) is to achieve desired predictive accuracy as well as maintain computational efficiency of corresponding numerical solutions. Existing modeling methods are primarily based on a) more traditional theories developed for fiber-reinforced polymer-matrix laminates and b) rebar- and shell based FEA approaches. Although mentality of these methods is widely used in rubber and tire engineering, these models often significantly simplify important issues of non-linearity and 3-D nature of interlaminar deformation. The objective of the paper, therefore, is to develop an efficient general modeling approach for typical laminated CRC capturing fundamental mechanisms of their deformation as well as providing relatively simple and cheap solutions. The approach uses advantages of previously developed methods (Gurvich) to quantify deformation of anisotropic elastomers. The present study is focused on 3D extension of the problem to account for crucially important interlaminar behavior of these composites. Several structural examples illustrate simplicity of implementation, demonstrate computational robustness, and show practical importance of obtained results. In particular, limitations of existing rebar-based models of CRC are shown and explained.
Thermal Oxidation Kinetics of Unvulcanized Unstabilized Polyisoprene
Authors: Colin X. , Audouin L. , Verdu J. 
Published: February 2011

Abstract
The thermal oxidation of an unvulcanized, unstabilized polyisoprene rubber (IR) has been studied in the 40–140 °C temperature range. Ageing was monitored by FTIR determination of double bonds and carbonyl groups, mass uptake measurement, and weight average molar mass determination. A mechanistic scheme based on the standard scheme for radical chain oxidation, but taking into account the diversity of initiation processes and the existence of inter and intramolecular radical additions to double bonds, was built. The kinetic model derived from this scheme is composed of seven differential equations to be solved in discretized thickness layers to take into account the kinetic control by oxygen diffusion. This system was numerically solved using a Matlab program dedicated to stiff systems of differential equations. The elementary rate constants and other kinetic parameters were then determined from experimental data, using an inverse approach. A set of physically reasonable parameter values was obtained, allowing thus to envisage lifetime predictions at low temperature (long term). The results lead to observations difficult to make from classical analytical studies, for instance the predominance of bimolecular hydroperoxide decomposition among other initiation modes or the competition between intermolecular hydrogen abstraction and intramolecular addition of peroxy radicals to double bonds.
Effect of Architecture on the Properties of Polyisobutylene-Based TPE Materials
Authors: Puskas Judit E. , Santos Lucas M. Dos , Sen Mustafa Y. , Kaszas Gabor 
Published: February 2011

Abstract
This paper will discuss the design and synthesis of polyisobutylene-based thermoplastic elastomers (TPEs) for biomedical and other specialty applications. The first generation from this class of polymers, linear triblock polystyrene-b-polyisobutylene-b-polystyrene (PSt-b-PIB-b-PSt or SIBS), is FDA-approved and currently used as the polymeric coating on drug-eluting coronary stents. TPEs with arborescent (dendritic) polyisobutylene core (arbPIB-b-PSt) the third generation, display unique combination of properties. Our latest results include the synthesis of surface-modified TPEs. This paper will give a short overview of the effect of architecture (number of branches, molecular weight and size) on select properties of arbPIB-based TPEs. It will be demonstrated that block copolymers with a high molecular weight dendritic (arborescent) polyisobutylene core and poly(para-methylstyrene) end blocks can manifest themselves either as a rubber, or as a plastic, depending on their environment. The behavior is thermally irreversible. We called this material the “chameleon thermoplastic elastomer.” This material represents a new concept in material science: ETPE (entropy-driven thermoplastic elastomer).
Dynamic Mechanical and Dielectric Properties of Nanocomposites of Natural Rubber (NR), Carboxylated Styrene Butadiene Rubber (XSBR) Latices and their Blends
Authors: Stephen Ranimol , Thomas Sabu , Raju K. V. S. N. , Varghese Siby , Joseph Kuruvilla , Oommen Zachariah 
Published: February 2011

Abstract
The viscoelastic and dielectric properties of nano structured layered silicates reinforced natural rubber (NR), carboxylated styrene butadiene rubber (XSBR) and their blends have been analyzed. The viscoelastic properties such as storage modulus, loss modulus, damping behavior and glass transition temperature of nano filled latices have been investigated. Upon the addition of filler, the storage modulus of nanocomposites was found to increase due to the enhancement in stiffness of the material. Due to the restricted mobility of polymer chain segments, the damping values decreased as a function of filler loading. An investigation of the viscoelastic properties revealed that there was a strong interaction between the polymer and the filler. Latex nanocomposites was characterized by X-ray diffraction technique. The enhanced d values indicated the intercalation of polymer chain into the layers of silicates. The dielectric properties of nanocomposites have been investigated as a function of frequency in the range of 50Hz–100KHz. The effect of frequency on dielectric permittivity (Ε′), dielectric loss (Ε″), dissipation factor (tan δ) and volume resistivity (ρv) of latex nanocomposite have been measured under alternating current. The dielectric permittivity of the samples was found to be higher upon the incorporation of nano fillers. The volume resistivity decreased due to the enhanced conductivity of filled samples.