bluuebunny/crossref_metadata_2025_split huggingface dataset:
Characterization of Polymer Adsorption on Disordered Filler Surfaces by Transversal 1H NMR Relaxation
Authors: Lüchow H. , Breier E. , Gronski W. 
Published: February 2011

Abstract
The transversal 1H NMR relaxation of the bound rubber shell of carbon black loaded elastomers can be decomposed into three relaxation regimes corresponding to the loosely bound rubber, the rubber that is immobilized on the carbon black surface and a third component of intermediate mobility. The relaxation time T2 of the intermediate component is related to the end-to-end distance of polymer segments between adsorption sites on the carbon black surface, by converting the relaxation times to length scales on the basis of recent work on NMR relaxation of elastomeric networks. From measurements on SBR loaded with carbon black N 220, a distance of 2.3 nm was obtained in agreement with characteristic dimensions of crystallite sizes and surface roughness as determined by atomic force and scanning tunneling microscopy. The analysis was applied to novel inversion blacks which give lower tan δ/60°C, and rolling resistance without affecting tan δ/0°C and wet skid behavior. These blacks were found to possess a higher density of adsorption sites and a greater surface roughness as compared to standard carbon blacks. In addition to the surface characterization, the analysis of the mobile component of the compound allowed the estimation of the density of entanglement couplings between the rubber matrix and the bound rubber shell.
Thermoplastic Elastomeric Blends of Nylon-6/Acrylate Rubber: Influence of Interaction on Mechanical and Dynamic Mechanical Thermal Properties
Authors: Jha Abhijit , Bhowmick Anil K. 
Published: February 2011

Abstract
Nylon-6 and acrylate rubber (ACM) were melt blended in a Brabender Plasticorder at 220 °C and 40 rpm rotor speed. The reactive nature of the blend is reflected in the mixing torque behavior of the blends at different compositions. The solubility characteristics of the blends in formic acid solution gives an approximate idea of the amount of nylon-6 grafted onto ACM and vice-versa. A reaction mechanism is proposed based on the well known epoxy—amine and epoxy—acid reactions and is confirmed by infrared spectroscopic studies of the blends. The influence of interaction between the two polymers on the mechanical and the dynamic mechanical properties of the blends is analyzed in detail, and the results are interpreted on the basis of the formation of nylon—ACM graft copolymer at the interfaces. The dynamic mechanical thermal analysis (DMTA) reveals a two phase morphological structure, indicating incompatibility of the blend components. The grafting reaction results in dramatic increase in both the storage modulus and the Young's modulus of blends. The presence of grafted rubber chains is reflected in the secondary transition of the rubber loss peak at higher temperature. Also, a substantial improvement in the damping properties of the blends in the service temperature range (i.e., 25 to 175 °C) is revealed from the DMTA results. The dynamic vulcanization of the ACM phase during melt mixing improves the elongation at break values of the blends.
Difunctional Initiator Based on 1,3-Diisopropenylbenzene: 7. Mechanical and Thermal Properties of New Butadiene-Based Thermoplastic Elastomers
Authors: Yu Y. S. , Dubois Ph , Jérôme R. , Teyssié Ph 
Published: February 2011

Abstract
Mechanical and thermal properties of SBS thermoplastic elastomers, in which S stands for polystyrene and B for polybutadiene, can be remarkably improved through end-capping by syndiotactic poly(methyl methacrylate) sequences. Furthermore, the upper service temperature of these sPMMA teleblock copolymers can also be enhanced by blending with isotactic PMMA so that the rubbery PBD soft segments are connected to high-melting stereocomplexed hard segments. The factors which affect the mechanical and thermal properties of these novel thermoplastic elastomers have been extensively investigated.
Improvement of Low-Temperature Flexibility of Hydrogenated Nitrile—Butadiene Rubber
Authors: Kobatake Takushi , Kodama Kazumi , Hayashi Sachio , Yoshioka Akira 
Published: February 2011

Abstract
Improvement of low-temperature flexibility of Hydrogenated Nitrile Butadiene Rubber (HNBR) is a requirement for industrial applications. In this study, the relationship between low-temperature flexibility and polymer structure—such as higher order structure and monomer unit distribution along a polymer chain—was examined for HNBRs having various nitrile contents, using X-ray diffraction, nuclear magnetic resonance, computer simulation, and other methods. It was found that the length of tetramethylene sequence in a polymer chain is the key factor for improving the low-temperature flexibility. Tetramethylene sequences having five or more than five continuously linked tetramethylene units (TM≥5) facilitate crystallization upon stretching, which leads to a poor low-temperature flexibility. Consequently, it is deduced that the TM≥5 content must be as low as possible to improve the low-temperature flexibility. Two methods were tried to decrease the TM≥5 content: (1) copolymerization with third monomers; and (2) addition of mercaptans. It has been confirmed that branched HNBRs made by each of the two methods have lower Tgs and improved low-temperature flexibility.
Reflectometry—A New Method of Measuring Filler Dispersion
Authors: Gerspacher M. , Nikiel L. , Yang H. H. , O'Farrell C. P. 
Published: February 2011

Abstract
A new method of measuring carbon black dispersion in rubber is presented. This method is based on the measurement of the light reflectivity from the rubber sample using standard equipment used in the evaluation of the tint strength of carbon black (ASTM D3265 procedure). This method can be applied for both uncured and cured samples; however, the uncured sample measurement has significant advantages in the simplicity of the sample preparation and obtaining important filler dispersion information of the compound. It is shown that samples with better dispersed carbon black reflect less light as compared to samples with poor carbon black dispersion.
The Influence of Matrix Viscosity and Interfacial Properties on the Dispersion Kinetics of Carbon Black Agglomerates
Authors: Yamada H. , Manas-Zloczower I. , Feke D. L. 
Published: February 2011

Abstract
The dispersion of carbon black agglomerates suspended in polydimethyl siloxane (PDMS) or polybutadiene (PBD) liquids has been studied. Agglomerates comprised of either a low-structure or a high-structure carbon-black were subjected to simple shear flow. Two characteristic length scales that affect the dispersion process are identified. One length scale (Lp) is a measure of the ease with which fluid can flow through the porous agglomerate structure. The second (δ) is a measure of the depth to which processing fluid has soaked into the agglomerate. Values of Lp were found to be independent of types or viscosity of the polymer but were sensitive to the structure and packing density within agglomerates. The parameter δ, which varies with time of immersion in the processing fluid, was found to be smaller at comparable immersion times for matrix fluids with high viscosity. Shearing experiments showed two kinetic regimes (fast and very slow dispersion). For each type of matrix liquid, there exists a critical packing density; agglomerates having a packing density lower than this critical value exhibit only fast erosion, but those with packing density higher than this critical value show dispersion kinetics that starts as fast but shifts to slow after a certain period of shearing. The critical packing density was higher in PBD than in PDMS for agglomerates of the low-structure carbon-black but was not significantly different for agglomerates of the high-structure carbon-black. The critical packing density was found to shift to higher values if higher viscosity PDMS was used. The dispersion kinetic regime for the different polymers liquids could be correlated with the value of δ/Lp. If δ/Lp remained less than a critical ratio, only fast erosion was observed. Measurement of fragment size distributions support the notion that fragments are produced primarily from the periphery of the agglomerate in the slow kinetic regime, but can be larger (up to the size of δ) for the fast kinetic regime.
Reinforcement of Acrylonitrile—Butadiene Rubber by Silica Generated in situ
Authors: Tanahashi H. , Osanai S. , Shigekuni M. , Murakami K. , Ikeda Y. , Kohjiya S. 
Published: February 2011

Abstract
In situ silica reinforcement was applied to the acrylonitrile—butadiene rubber (NBR) vulcanizates. The amount of in situ silica introduced in the NBR vulcanizates was limited due to the high polarity of NBR. The presence of γ-mercaptopropyltrimethoxysilane (γ-MPS) in the NBR vulcanizate increased the conversion of TEOS in the sol-gel reaction and resulted in the higher amount of in situ silica, compared to the system without γ-MPS. The obtained silica was very fine and dispersed very homogeneously. In situ sol-gel reaction of TEOS in the NBR vulcanizates mixed with a conventional silica (VN-3) was also carried out. The reinforcement efficiency in this system increased with the increase of the amount of mechanically mixed conventional silica. Interestingly, the hysteresis loss decreased by the in situ filling of silica.
Crack Growth in Twisted Rubber Disks. Part I: Fracture Energy Calculations
Authors: Aboutorabi H. , Ebbott T. , Gent A. N. , Yeoh O. H. 
Published: February 2011

Abstract
When a thin bonded rubber disk is subjected to repeated torsional strains by rotating one end-piece with respect to the other, an initial circumferential crack grows inwards. This is the basis of a new test method for determining rates of growth of a fatigue crack in rubber. Values of torsional stiffness K for a partially-cracked disk are computed here by FEA and corresponding fracture energies G are deduced in terms of the shear modulus μ, radius r of the still-uncracked portion, and rotation angle ϕ, assuming that the rubber compound is linearly elastic. Values obtained for G are shown to vary with r2, and thus decrease rapidly as the crack grows and the radius of the uncracked portion decreases. They are approximately the same as values obtained when the cracked disk is assumed to be equivalent to a solid disk having a slightly larger radius than the actual uncracked portion. For thin disks the correction in radius for K is approximately 0.22h, and for G approximately 0.33h, where h is the disk thickness. Measurements of crack growth rates dc/dn for a wide range of values of fracture energy G are described in Part II, the next paper in this issue.
Ultrasonic Devulcanization of SBR Rubber: Experimentation and Modeling Based on Cavitation and Percolation Theories
Authors: Yushanov S. P. , Isayev A. I. , Kim S. H. 
Published: February 2011

Abstract
Continuous ultrasonic devulcanization of styrene-butadiene rubber (SBR) is considered. Experiments are performed under various processing conditions. Two recipes of SBR with different amounts of polysulfidic linkages are utilized. Gel fraction and crosslink density of devulcanized rubbers are measured and a unique relationship between them is established. This relationship is found to be in agreement with the 3D percolation theory. Die characteristics with and without imposition of ultrasonic waves are determined. A modification of acoustic cavitation and flow modeling of ultrasonic devulcanization of SBR is proposed using a concept of effective viscosity characterizing the flow of vulcanized particles before devulcanization combined with a shear rate, temperature, and gel fraction dependent viscosity of devulcanized rubber. Velocity, shear rate, pressure, and temperature field along with gel fraction, crosslink density, and number of bonds broken are simulated. Predicted data on gel fraction, crosslink density, amount of poly-, di- and monosulfidic bonds, and pressure are found to be in qualitative agreement with experimental data.
Application of Reproducing Kernel Particle Method to Large Deformation Contact Analysis of Elastomers
Authors: Chen Jiun-Shyan , Pan Chunhui , Wu Cheng-Tang 
Published: February 2011

Abstract
A meshless formulation based on the Reproducing Kernel Particle Method (RKPM) is applied to the large deformation and contact analysis of elastomeric components. In this approach, a kernel estimate that ensures the completeness requirement of a linear field is introduced to construct the global Reproducing Kernel shape functions of the displacements. The Galerkin approximation of the variational equation is formulated using the Reproducing Kernel shape functions, and the discretization can be performed without the need of a structured mesh. In this paper, a RKPM formulation for rubber materials including frictional contact conditions is presented. The contact constraint equations and essential boundary conditions are formulated in the nodal coordinate using a direct transformation method. The global Reproducing Kernel shape functions expressed in a material description are used in the total Lagrangian formulation of hyperelasticity. By the use of the smooth Reproducing Kernel shape functions, the method is effective in dealing with large deformation and contact conditions in elastomeric applications.
Stem Length and Stem Length Distribution of Chain-Folded Lamellar Crystal Grown from Dilute Solution of cis-1,4-Polyisoprene by Ozonolysis-GPC Measurements
Authors: Kawahara Seiichi , Inomata Yoriko , Kakubo Takashi , Tanaka Yasuyuki , Hatada Kouichi , Ute Kouichi , Miyatake Nobuo 
Published: February 2011

Abstract
Lamellar crystal of natural rubber (NR), deproteinized natural rubber (DPNR), transesterified natural rubber (NR-TE) and synthetic cis-1,4-polyisoprene was grown from 0.2% (w/v) hexane solution at the temperature between −50 and −70 °C. The stem length and stem length distribution of the lamellar crystals were investigated by gel permeation chromatography (GPC) and supereritical fluid chromatography (SFC) of the ozonolysis products. The stem length (L) was detected as the number of isoprene units of ozonolysis products. A broader stem length distribution ranging from 2-mer to 13-mer in the single traverse element was found for the solution-grown crystal, suggesting an irregular structure of the lamellar crystal of the polymer. The stem length distribution of NR was narrowed by transesterification due to the decomposition of branching of NR. The equilibrium melting temperature was determined to be −17.5 °C from a plot of melting temperature versus inverse stem length, for the solution-grown crystal of transesterified DPNR.
The Effect of Bis(3-Triethoxysilylpropyl) Tetrasulfide on Silica Reinforcement of Styrene-Butadiene Rubber
Authors: Hashim A. S. , Azahari B. , Ikeda Y. , Kohjiya S. 
Published: February 2011

Abstract
Bis(3-triethoxysilylpropyl)tetrasulfide (TESPT) was found to affect the curing characteristics and the physical properties of styrene-butadiene (SBR) gum rubber and xin situ silica-filled SBR vulcanizates. Silica incorporated by the in situ sol-gel reaction of tetraethoxysilane with TESPT showed a much higher reinforcing efficiency than did conventional mechanical mixing and the in situ method without TESPT. The higher reinforcing efficiency is attributed to the formation of a silica-rubber network, which also changed the dynamic mechanical behavior of the SBR vulcanizates. Transmission electron microscopy observations showed in situ silica incorporation of very fine particles in comparison to the sol-gel process without TESPT.
FTIR Analysis of Silica-Filled Natural Rubber
Authors: Kralevich Mark L. , Koenig Jack L. 
Published: February 2011

Abstract
The interactions of silica filler in zinc activated, sulfur vulcanized cis-1,4-polyisoprene (IR) were characterized using Fourier Transform Infrared (FTIR)-Attenuated Total Reflectance (ATR) spectroscopy. The variables examined were increased levels of silica and quality of mixing of the batch. The increased silica level resulted in band broadening and a frequency shift to lower wavenumbers of the silica absorbance region (1250-1000 cm−1) due to a combination of physical and chemical adsorption of the rubber and parts of cure system on the silica surface. The peaks that appeared near 1040 and 1017 cm−1 were attributed to physical interactions between silica and the natural rubber. However some chemical bonding of the IR was present as a result of a free radical reaction that takes place during the milling process. Inefficient mixing had an affect comparable to adding less filler, according to the results above. That is, there was less “effective” filler in the poorly mixed samples because poor dispersion promotes agglomeration of the polar silica in the nonpolar hydrocarbon rubber.
Black and White Fillers and Tire Compound
Authors: Donnet Jean-Baptiste 
Published: February 2011

Abstract
The present stand on the understanding of the role of fillers in elastomer compounds shall be reviewed and discussed. Unpublished results of our laboratory are also introduced in this review paper, particularly concerning silica observed by atomic force microscopy and scanning probe microscopy and recent transmission electron microscopy results concerning furnace carbon black and its inception and growth.
Structurally Realistic Modeling of Elastomers
Authors: Burkhart Craig W. 
Published: February 2011

Abstract
This review covers the methods by which elastomers have been microscopically modeled and simulated since the mid-1960s. Of particular importance was the rotational isomeric state (RIS) methods of the Flory school in the 60s. His group was the first to attempt to use such statistical mechanical methods to determine observables such as the characteristic ratio, Cn. The early success of Flory's efforts were expanded in the early 1970s by members of his group in what appears to be the first true attempt to use molecular mechanics optimization techniques to obtain RIS statistical weighting matrices. Following these two pioneering breakthroughs, molecular mechanics techniques were refined and extended. Not much later, it became possible to perform temporal molecular dynamics simulations on flexible molecular liquids. Simulations of elastomer systems lagged somewhat; both single chains and elastomer amorphous liquids were not studied until the beginning of this decade. With the improvement in molecular forcefields and computational horsepower, it has become possible to perform simulations on relatively large-scale polymer systems. We track these developments, which include equation-of-state simulations and the simulation of oxygen diffusion in elastomers.
Contact-Mechanics-Based Studies of Adhesion between Polymers
Authors: Mangipudi V. S. , Tirrell M. 
Published: February 2011

Abstract
Contact mechanics deals with the deformation of solid bodies in contact. In recent years, significant advances have been made both in the theoretical and experimental areas of contact mechanics, especially in the area of soft solids, in relating the contact deformation to interfacial adhesion. On the theoretical front, new theories of contact mechanics have been developed to relate the interfacial force induced deformation to the thermodynamic work of adhesion both for elastic and viscoelastic solids. On the experimental front, several new techniques have been developed to measure the interfacial forces and the interfacial-force-induced deformations. These techniques have been used, with the aid of the theories of contact mechanics, to measure directly the surface and interfacial energies of a variety of polymers and other model surfaces. These experimental and theoretical developments have also been exploited to measure quantitatively the effect of interfacial chain diffusion on the adhesion of polymer interfaces.
We summarize the recent developments in the theories of contact mechanics, and their applications in the design and interpretation of experimental measurement of molecular level adhesion between elastomers, glassy and viscoelastic polymers. We also review the experimental and theoretical developments related to the role of chain diffusion on interfacial adhesion. Finally, we identify some potential new applications of contact-mechanics-based techniques in such emerging area of adhesion science as molecular level studies of adhesion of viscoelastic materials and biomaterials.
Specialty Elastomers for Automotive Applications
Authors: Hashimoto Kinro , Maeda Akio , Hosoya Kiyoshi , Todani Yoshihiro 
Published: February 2011

Abstract
Various elastomers are used for automotive components because of their physical properties, chemical properties, durability, etc. There are belts to transmit energy, seals to support radial or reciprocating parts, gaskets and O-rings to seal in oils and fuels, hoses to deliver liquid and gases and diaphragms to control them. Figure 1 shows one example of elastomers for gasoline engines reported by Akema and Yoshida. Rubbers are soft polymeric materials having generally 100 MPa of Young's modulus (shown in Figure 2) for the normally applied temperature range. They are widely used for the buffer position between high modulus materials such as metals, plastics, glasses, etc., in energy transmission, liquid delivery, and energy isolation positions. The materials are selected for their resistance to fuels, oils, and heat; as well as their cold flexibility and sealing ability. However, different materials are sometimes selected for the same device depending upon such factors as applied temperature, class of fuels and oils, and the engineering design of the car. The many problems confronting the automotive industry these days are shown in Table A-I. They are roughly classified into two areas: environmental and safety. Elastomers for automotive applications have been changing to solve many kinds of problems. Table A-II shows the trends of rubber materials being used for automotive parts. High performance rubbers, which have heat resistance, long life, low permeability, good abrasion resistance, and so on, are all being adopted.