bluuebunny/crossref_metadata_2025_split huggingface dataset:
Carbon-Black-Elastomer Interaction II: Effects of Carbon Black Surface Activity and Loading
Authors: Ayala J. A. , Hess W. M. , Joyce G. A. , Kistler F. D. 
Published: February 2011

Abstract
Carbon black morphology, surface activity and loading have been varied systematically to study the effects on an SBR formulation. The surface activity of five commercial grades of carbon black was varied by heat treating the standard grade samples at 1100°C and 1500°C in an inert atmosphere. Measurements on carbon black-elastomer interaction were based on a parameter I, defined elsewhere. The parameter I exhibited the previously reported correlation with known indicators of the surface activity of carbon blacks. The heats of adsorption by inverse gas chromatography at infinite dilution have been found useful as a measure of the carbon-black surface energy related to rubber interaction. These measurements have been employed in conjunction with carbon-black morphology and loading to develop a surface-area-modified and a surface energy-modified effective volume fraction V′ and ψ, respectively. The parameter V′ was utilized to explain the variation of the dynamic elastic modulus E′ at 1 % double strain amplitude (DSA) for all rubber compounds. The parameter ψ was used to explain the variation of E′ at 25% DSA and the factor σ in the calculation of I. The parameters V′ and ψ provide a model for the estimation of I from fundamental carbon-black morphological properties and surface energy.
Electropolymerization of Aniline on Conductive Vulcanizates and Charge-Discharge Properties
Authors: Mori Kunio , Oishi Yoshiyuki , Hirahara Hidetoshi , Kumagai Naoaki , Tanno Kazuo 
Published: February 2011

Abstract
To obtain electrode materials with good charge-discharge properties, the electrochemical polymerization of aniline on conductive vulcanizates containing Ketjin black was investigated along with the charge-discharge properties of these materials. When EPDM vulcanizates containing Ketjin black greater than 20 phr were used as working electrodes, the polymerization of aniline occurred easily and conductive laminates of vulcanizate and polyaniline were obtained. This required an EPDM vulcanizate conductivity of more than 0.1 S/cm. The selection of elastomers and solvents for the electrochemical reaction is important. A combination of EPDM and water solvent was found to be suitable for the electrochemical polymerization of aniline. Polyaniline products on vulcanizate electrodes had lower film densities than polypyrrole products, and exhibited greater adhesion to the vulcanizates than to Pt electrodes. Li battery cells, using these polyaniline vulcanizate electrodes, possessed remarkably higher charge-discharge capacity and greater cycles life than the polyaniline Pt electrode. The vulcanizate electrode retained good charge-discharge properties even at a current density exceeding 1.0 mA/cm2.
Reduced Time Approach to Curing Kinetics, Part I: Dynamic Rate and Master Curve from Isothermal Data
Authors: Chan T. W. , Shyu G. D. , Isayev A. I. 
Published: February 2011

Abstract
A reduced time approach has been used to predict nonisothermal curing kinetics based on isothermal kinetic data. This approach makes it clear that the conversion in a kinetic process is a function of the reduced time alone and allows for the construction of a master curve from isothermal kinetic data, indicating that the dynamic (or nonisothermal ) rate is equal to the isothermal rate. The approach can be applied to curing, crystallization, and other physico-chemical kinetics. A method is also described for correcting the nonisothermal curing kinetic data obtained from differential scanning calorimetry ( DSC ) for a temperature lag between the sample and the DSC furnace. For two rubber compounds, it has been found that the nonisothermal curing kinetic data corrected for this temperature lag are in better agreement with the predictions based on isothermal kinetics than the uncorrected data.
Cure and Mechanical Behavior of Rubber Compounds Containing Ground Vulcanizates. Part II—Mooney Viscosity
Authors: Gibala D. , Laohapisitpanich K. , Thomas D. , Hamed G. R. 
Published: February 2011

Abstract
Mooney viscosities and thixotropic behavior have been determined for SBR melts containing carbon black and/or ground vulcanizate particles. A composition containing ambiently ground rubber has a higher viscosity than one with cryogenically ground rubber. This is attributed to occlusion of continuum rubber within the sponge-like, ambiently ground rubber; occlusion is not possible with the smooth, cryo-ground particles. Viscosity was independent of particle size. On an equal phr (weight) basis, the addition of N330 carbon black and cryo-ground rubber augment Mooney viscosity to a similar extent. While the Guth-Gold Equation is approximately applicable to black-filled melts, samples containing ground rubber are a much better fit by the simple Einstein Equation. Ground rubber addition has only a minor influence of thixotropy, in contrast to carbon black, which greatly increases thixotropy.
Electron Beam Initiated Grafting and Crosslinking of Ethylene Vinyl Acetate Copolymer. Part-I: Structural Characterization
Authors: Datta Sujit K. , Chaki Tapan K. , Bhowmick Anil K. 
Published: February 2011

Abstract
Electron beam irradiation of Ethylene vinyl acetate, EVA (VA content 12, 28 & 45%) copolymer was carried out in presence of trimethylolpropane trimethacrylate (TMPTMA) and triallyl cyanurate (TAC) and the structure of the modified copolymers was determined with the help of IR spectroscopy and gel content measurements. The IR absorbance peak at 1640 cm−1 disappears at lower radiation dose indicating that the grafting and crosslinking reactions take place through double bonds. Some carbonyl groups are formed during irradiation. The concentration of carbonyl group increases with the radiation dose and the level of multifunctional monomers. The grafting level of TAC onto EVA determined from IR absorbance peak at 1565 cmx−1 remains almost constant with the variation of radiation dose and increases with TAC level. The gel content increases with radiation dose, but changes marginally with TMPTMA and TAC levels. The percent gel content increases linearly with vinyl acetate content in EVA.
Strain Dependence of Dynamic Mechanical Properties of Carbon Black-Filled Rubber Compounds
Authors: Ulmer J. D. 
Published: February 2011

Abstract
The strain dependencies of dynamic mechanical properties of carbon black-filled rubber compounds have been modeled by Kraus. Evaluation of the Kraus model with carbon black loadings up to 110 phr shows that it provides a fairly good overall description of elastic modulus, G′, as a function of strain, γ. The model description of G′ strain dependence improves with decreased carbon black loading, and is very good with carbon black loadings of 50 phr and less. The model description of viscous modulus strain dependence, G″(γ), is less successful than the G′(γ) description. Several empirical modifications of the viscous modulus model are examined. The most improved model is a very good approximation to viscous modulus over a wide experimental strain-range. Its utility, and that of the Kraus G′(γ) model, are illustrated through calculation of simple shear dynamic properties from torsion property measurements on a solid cylinder, where the strain amplitude varies across the specimen radius. The models allow transformation of the apparent moduli, reported as functions of strain amplitude at the cylinder's outer edge, to their true counterparts, G′(γ) and G″(γ), as functions of uniform strain amplitude. Although the G′(γ) and modified G″(γ) models apply to a wide range of experimental strains, some uncertainties associated with each model's accuracy remain, and there are inconsistencies in the relation of one model to the other. Reservations associated with the models might be resolved through refined treatments of the test specimen geometries.
Viscoelastic Behavior of Styrene-Butadiene-Styrene Block Copolymers in Temperature Range of Glass-Rubber Transition of Styrene Block
Authors: Nakajima N. 
Published: February 2011

Abstract
Dynamic mechanical measurements were performed with styrene-butadiene-styrene (SBS) block copolymers, Kraton D-1101 and D-l 102. Isochronal data were obtained from −130 to 85°C in the tensile mode at 1 Hz and from 60 to 160°C in the shear mode at 1 rad/s. The isothermal measurements were also performed at 60, 90, 120, 140, and 160°C in the frequency range of 0.0316 to 100 rad/s. The results suggest that the two polymers have different morphologies although the styrene content and the diblock content are about the same for both polymers. Kraton D-1101, which has 1.5 times higher molecular weight, has 3–5 times higher rubbery modulus, compared to D-1102. The lower molecular weight polymer, D-1102, appears to have a larger amount of the mixed phase at the boundary. This is suggest by the lower temperature of the “domain disruption”, Tdd and the higher magnitude of tan δ at Tdd. This explains the difference in the rubbery moduli of the two polymers.
Chemical Modifications of Rubber Surfaces: XPS Survey of the Reactions of Trichloroisocyanuric Acid at the Surfaces of Vulcanized Elastomers
Authors: Lawson David F. , Kim Kyung J. , Fritz Tammy L. 
Published: February 2011

Abstract
X-ray photoelectron spectroscopy (XPS or ESCA) was used to examine the outermost 100 A˚ of selected elastomer substrates, and to classify the predominant reactions that occur there between the substrates and trichloroisocyanuric acid (TCICA). About four monolayers deep, this surface region represents the locus of interfacial and adhesive processes. From these experiments, we concluded the following: (1) at the outermost surface of NR, substitution reactions of TCICA predominate, but a minor amount of addition is also evident; (2) addition and substitution reactions compete on the surfaces of the butadiene-containing polymers, BR and SBR; (3) no detectable functionalization by TCICA takes place on EPDM or CIIR — polymers which lack sufficient olefinic sites for surface modification; (4) isocyanuric acid or other nitrogenous residues are present on treated surfaces before washing; (5) reconstruction of functionalized surfaces may occur upon swelling for extended periods; (6) surface oxygen levels in these experiments were variable, and could not be relied upon as indicators of the functionalization chemistry.
A New Carbon Black-Rubber Coupling Agent to Improve Wet Grip and Rolling Resistance of Tires
Authors: González L. , Rodríguez A. , de Benito J. L. , Marcos A. 
Published: February 2011

Abstract
The compound p-aminobenzenesulfonyl azide was developed as a new type of carbon black to rubber coupling agent. Its addition to rubber compounds increases resilience and moduli while reducing abrasion loss. The behavior of this coupling agent is confirmed by the dynamic mechanical response of the vulcanizates—the rubber Tg is shifted to higher temperatures. Rubber compositions containing this coupling agent may be used in tire treads to reduce rolling resistance and improve wet skid resistance. These attributes were estimated from dynamic property measurements.
Styrene-Butadiene Rubber Filled with Fluorinated Carbon Black: Part II. Effect of Curative Level
Authors: Ames K. , Gibala D. , Hamed G. R. 
Published: February 2011

Abstract
The cure and tensile properties of sulfur vulcanized styrene-butadiene rubber filled with a conventional furnace black or a fluorinated black have been determined. Compositions with the fluorinated black and normal curative levels exhibit retarded cure compared to corresponding ones with the furnace black. This is due to a reaction between the sulfenamide accelerator and the fluorinated black. Notwithstanding, a fluoro-filled composition with no curatives substantially crosslinks when molded at 150°C. Thus, fluoro-black filled specimens have competing effects toward crosslinking. On the one hand, crosslinking is inhibited by reaction with the accelerator, while, on the other hand, the fluoro-black itself can cause crosslinking.
Injection Molding of Rubber Compound with Rheology Affected by Vulcanization: Part I. Material Characterization
Authors: Isayec A. I. , Wan M. 
Published: February 2011

Abstract
Rheological behavior of rubber is highly sensitive to the thermal history and cure kinetics. Rheological characterization for SBR compound is carried out using a capillary rheometer and modified Mooney viscometer. The viscosity function, which is not only temperature and shear-rate dependent but also cure-level dependent, is constructed. A modification of Cross model is proposed and verified to predict the rheological and chemorheological behaviors of SBR compounds. This rheological characterization is combined with vulcanization kinetic characterization. The parameters of vulcanization are obtained from DSC measurement under several nonisothermal conditions. The significance of correcting for temperature lag in the DSC measurements and the corresponding rate-of-vulcanization lag resulting from the nonisothermal DSC scan is illustrated. The proposed rheological function is further modified to incorporate the temperature- and state-of-cure-dependent yield behavior of rubber compounds at low shear rates. The proposed model is suitable for use in the simulation of processing operations.
Injection Molding of Rubber Compound with Rheology Affected by Vulcanization: Part II. Modeling and Experiment
Authors: Wan M. , Isayev A. I. 
Published: February 2011

Abstract
Experimental and theoretical results are reported on the effect of vulcanization on viscosity and yield stress during cavity filling with an SBR compound. Rheological and vulcanization models were utilized in simulation of the cavity filling process. Numerical schemes was based on the hybrid approach of control volume finite-element and finite-difference techniques. The pressure profiles at various locations along the flow path in the mold during cavity filling were obtained by conducting the experiments at various mold and inlet temperatures and mold injection speeds. It was found that the predicted pressure profiles followed the trend determined in the experiments. Comparing two versions of the modified Cross viscosity models — with and without the effect of cure on viscosity — it appears that use of a viscosity model which accounts for the cure-effect improves the accuracy, and thus the usefulness, of the cavity pressure prediction models. Evolution of the state-of-cure in the postfilling process are predicted and compared with the state-of-cure in moldings. The predicted results on the development of the state-of-cure during the postfilling stage show good agreement with the experimental data. The rubber compound exhibits yield behavior during cavity filling at very low injection speeds. The modified Cross model was further extended to include the yield stress and was implemented in the simulation program. In the case of low injection speed, the results showed a significant improvement in the prediction of cavity pressure, compared with the earlier reported predictions.
Thermoelastic Generalization of Isothermal Elastic Constitutive Models for Rubber-Like Materials
Authors: Zeng Nianning , Haslach Henry W. 
Published: February 2011

Abstract
Existing thermoelastic constitutive models are not able to predict important thermal properties of rubbers. For example, the modified entropic elasticity theory fails to predict that the temperature coefficient of stress, the energetic contribution to the stress, and the specific heat at constant deformation depend on both deformation and temperature. A class of thermoelastic constitutive equations is proposed that generalizes given isothermal models and predicts the temperature and deformation dependence. The Helmholtz free energy is written as the sum of the isothermal energy function, but with temperature-dependent material moduli, and a function of temperature. Conditions on the Helmholtz energy are given to ensure that three inversion effects which characterize rubber are predicted. As an application, an isotropic, homogeneous, mechanically incompressible thermoelastic constitutive equation is generalized from the isothermal Mooney-Rivlin model. The three uniaxial thermal inversion effects are successfully reproduced by this model.
Porosity in Rubber, a Review
Authors: Kasner A. I. , Meinecke E. A. 
Published: February 2011

Abstract
An overview of the causes and effects of porosity in rubber has been presented. The formation of porosity in rubber can be attributed to the heterogeneous nucleation and diffusion controlled bubble growth. The process proceeds simultaneously with vulcanization, so bubble formation in viscous fluids and in crosslinked rubber has been used to elucidate the mechanism. Porosity is caused by the supersaturation of rubber with volatiles and by insufficient external pressure during vulcanization. Some of the sources of these volatiles have been described. The effects of compounding, mixing and processing on porosity have been covered, and various methods of detecting and preventing porosity have been reviewed. Finally, the effects of porosity on the mechanical properties of rubber have been described.
Recent Advances in Anionic Synthesis of Functionalized Elastomers Using Functionalized Alkyllithium Initiators
Authors: Quirk Roderic P. , Jang Sung Hoon , Kim Jungahn 
Published: February 2011

Abstract
The results described herein demonstrate the advantages of functionalized initiators with respect to the efficiency of α-chain-end functionalization and the ability to effect post-polymerization functionalization and linking reactions with the living ω-carbanionic chain ends. Not all functionalized initiators are useful, however, because either: (a) they are not soluble in hydrocarbon solvents; or (b) they are not reactive enough to initiate polymerization at rates which are competitive with propagation to prepare polymers with narrow molecular weight distributions and controlled molecular weights; or (c) they are either too difficult to prepare or too expensive to prepare to be readily available for commercial elastomer production. The advantages of using funcitonalized initiators, however, should encourage further scientific and technological developments in this area.
Dynamically Vulcanized Thermoplastic Elastomers
Authors: Abdou-Sabet S. , Puydak R. C. , Rader C. P. 
Published: February 2011

Abstract
Thermoplastic elastomers (TPEs) exhibit the functional properties of conventional thermoset rubber, yet can be processed on thermoplastic fabrication equipment. The great majority of TPEs have hetero-phase morphology, whether the TPE is derived from block copolymers, rubber-plastic compositions or ionomers. Generally speaking, the hard domains (or the ionic clusters) undergo dissociation at elevated temperatures, thus allowing the material to flow. When cooled, the hard domains again solidify and provide tensile strength at normal use temperatures. The soft domains give the material its elastomeric characteristics. In this review article, the focus is on rubber-plastic polymer compositions as a group of TPEs which have achieved significant growth in the marketplace in the last two decades. The growth has been primarily in the nonpolar (olefinic) elastomer/polyolefin thermoplastic materials because of the wide range of products generated, their performance and their significant acceptance by the automotive sector in applications requiring elastic recovery. The field of TPEs based on polyolefin rubber-plastic compositions has grown along two distinctly different product lines or classes: one class consists of a simple blend and classically meets the definition of a thermoplastic elastomeric olefin (TEO), commonly called a thermoplastic polyolefin (TPO) in earlier literature. In the other class, the rubber phase is dynamically vulcanized, giving rise to thermoplastic vulcanizates (TPVs), named elastomeric alloys (EAs) in some previous literature. Both the simple blends and the dynamically vulcanized TPEs have found wide industrial application. It is the dynamically vulcanized TPE that has the performance characteristics required for true thermoset rubber replacement applications. The first TPE introduced to the market based on a crosslinked rubber-plastic composition (1972) was derived from W. K. Fisher's discovery of partially crosslinking the EPDM phase of EPDM/polypropylene (PP). Fisher controlled the degree of vulcanization by limiting the amount of peroxide, to maintain the thermoplastic processability of the blend. Crosslinking was performed while mixing, a process known as dynamic vulcanization. It is worth noting, however, that the dynamic vulcanization process and the first crosslinked EPDM/PP composition were discovered independently by Gessler and Haslett and by Holzer, Taurus and Mehnert in 1958 and 1961, respectively. Significant improvement in the properties of these blends was achieved in 1975 by Coran, Das and Patel by fully vulcanizing the rubber phase under dynamic shear while maintaining the thermoplasticity of the blend. These blends were further improved by Abdou-Sabet and Fath in 1977 by the use of phenolic curatives to improve the rubber-like properties and the flow (processing) characteristics.
Tire Traction vs. Tread Compound Properties—How Pavement Texture and Test Conditions Influence the Relationship
Authors: Veith Alan G. 
Published: February 2011

Abstract
A comprehensive test program conducted on a wide range of compounds with varying Tg and carbon black-oil reinforcement levels, shows that wet traction is influenced by two viscoelastic parameters: tan δ/E′, which represents the hysteresis or deformation friction component, and E″, the adhesion component. Both of these components jointly determine overall traction performance. However the individual component dependence as well as the combined dependence, traction vs. the viscoelastic parameters, changes as pavement texture and test conditions change. These changes may include performance reversals. The mechanisms responsible for most of this behavior are described. The relevance of these relationships to current wet traction evaluation procedures is also discussed.
Studies on a New Antireversion Agent for Sulfur Vulcanization of Diene Rubbers
Authors: Schotman A. H. M. , van Haeren P. J. C. , Weber A. J. M. , van Wijk F. G. H. , Hofstraat J. W. , Talma A. G. , Steenbergen A. , Datta R. N. 
Published: February 2011

Abstract
The mechanism of biscitraconimides (BCI) as antireversion agents for sulfur vulcanized diene rubber was investigated choosing squalene as a model substrate. Curing of squalene with sulfur in the presence of accelerator, activator and BCI at 170°C gave BCI bridged adducts. The products were identified by spectroscopic methods as being results of a Diels-Alder reaction of BCI (dienophile) with conjugated polyenes that are formed as a result of reversion. The rate at which the sulfur network degrades is comparable to the rate in which BCI adduct is formed. As a result of this, a nearly constant crosslink density is obtained after optimum cure time (t90). Based on this concept, the advantage of using 1,3-bis-(citraconimidomethyl) benzene (BCI-MX), a representative of the BCI-class, in NR based compounds is examined.