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

Abstract
A number of different techniques were applied to measure carbon-black-surface reactivity and the level of black-polymer interaction in four different elastomer systems (SBR, IIR, NR, and NBR) representing differences in unsaturation, crystallinity and polarity. Known within-grade surface activity variations were based on partial graphitization of an N121-type carbon black. The surface activity of different black grades was studied as a function of variations in both surface area and DBPA. Direct measurements of carbon-black-surface reactivity were based on hydrogen analysis, SIMS, IGC, and moisture adsorption. In-rubber measurements included bound rubber, SIMS of cut surfaces, and an interaction parameter, σ/η, which is derived from the slope (σ) of the stress-strain curve at low elongations, and (η), the ratio of dynamic modulus (E′) at 1% and 25% DSA. The following trends were observed: 1. The σ/η values provided a good measure of black-polymer interaction in all four polymer systems for either the within-grade or across-grade comparisons. 2. Higher σ/η values were indicated for SBR and NBR, followed by NR and IIR in that order. 3. SBR indicated the greatest sensitivity for bound-rubber measurements in terms of distinguishing within-grade variations in black-polymer interaction, followed by IIR, NR, and NBR in that order. 4. Positive SIMS on dry carbon black indicates the presence of complex hydrocarbon structures suitable for chemical reactivity at the carbon-black surface. 5. SIMS analyses on the dry carbon blacks exhibited intensity variations in the negative hydrocarbon fragments which were in line with the within-grade variations in hydrogen content. 6. SIMS analyses on the cut-rubber compound surfaces showed overall variations in intensity which were proportional to the range and level of the bound-rubber measurements. The most meaningful variations were recorded for SBR and IIR. 7. Heats of adsorption derived from IGC measurements with different adsorbates showed an excellent correlation with black-polymer interaction for the within-grade studies. Measurements across grades did not correlate as well with the in-rubber measurements, but the best results were obtained using styrene as the adsorbate. 8. The within-grade moisture adsorption measurements showed excellent agreement with IGC and the other techniques for the N121 series of heat-treated carbon blacks.
Role of Phenolic Tackifiers in Polyisoprene Rubber
Authors: Magnus F. L. , Hamed G. R. 
Published: February 2011

Abstract
The effect of p-tert-octyl phenolic (PTOP) resin on the tack of an IR/N660 compound has been studied before and after aging. The phenolic resin has little effect on unaged tack. Upon aging at 23°C and 45% RH, autohesion of the IR/N660 significantly decreases. However, when the PTOP resin is added, tack is maintained during aging. FT-IR attenuated total reflectance analyses indicate that, upon aging, oxidation leads to cis → trans isomerization. The PTOP resin becomes enriched in the surface region and protects the IR from further oxidation and the accompanying cis → trans isomerization. Additionally, solubilized resin may behave as a plasticizer to enhance tack bond formation. A compound with phenolic monomer (PTOP resin precursor) forms a rapid bloom with aging and experiences rapid tack loss.
Methacrylate Star Synthesis by GTP
Authors: Simms J. A. 
Published: February 2011

Abstract
All process conditions were picked to minimize the back-biting termination reaction so the maximum level of living arm could be carried into the core-forming step. Major contributors to control of termination were: 1. Using 0.2% (mole basis) of catalyst on initiator instead of higher concentrations. Within the constraints defined below, this produces a robust process that is insensitive to minor changes in materials, temperatures, and rates of addition. 2. Minimizing the time between arm formation and core formation. Polymerization of arm monomethacrylate to about 96 to 98% before core formation was the aim because conversion to &gt;99% would have allowed too much time for termination to proceed. 3. Adding core-forming monomer (ethylene glycol dimethacrylate) in about 5 min to keep monomer concentration high in this step. Faster add times may not be desirable because of mixing difficulties in this extremely fast polymerization. 4. Reaction solvent mixture containing 50% tetrahydrofuran. This allowed the reflux temperature to be about 85°C. 5. Keeping monomer concentration high in the arm-forming step by starting the polymerization with half of the monomer in the reactor. This forced the polymerization past the trimer stage, where termination is fastest. 6. Starting the reaction at room temperature so the exotherm could be dissipated by the heat capacity of the system. Two lots of trimethylsiloxyethyl methacrylate used to introduce hydroxyl groups into the product (after unblocking) gave different rates of polymerization, with one lot reaching the core-forming step in about half the time of the other. The monomer lot with the higher reactivity also led to higher levels of free arm. Stars made at high (2.0%) catalyst levels were quite unstable to molecular weight and viscosity increase. Mechanistic studies show that the increase is probably because of star/ star free-radical methacrylate polymerization involving pendant residual methacrylate unsaturation from the core-forming step. Stars made under the recommended conditions using 0.2% catalyst and the above process steps are probably stable enough for commercial use.
A Method to Resolve the Properties of Individual Phases in Carbon-Black-Loaded Elastomer Blends
Authors: Bauer R. F. , Crossland A. H. 
Published: February 2011

Abstract
Properties of the individual phases in a 70/30 carbon-black-loaded BR/NR blend could be successfully resolved using large deformation stress-strain modelling. Since the dispersed NR phase of the example had a lower modulus than the continuous BR phase, the interaction between the blend phases could be modelled by a simple parallel coupling arrangement. The stress behavior of each individual carbon-black-loaded polymer phase was then determined with respect to strain using a specially derived stress-strain relationship. The blend components also have to be characterized with respect to state-of-cure by empirically establishing how the parameters in the stress-strain relationship vary with respect to cure. The properties of the phases in the blend are then determined by finding the combination of component parameters which precisely reproduce the stress-strain behavior of the blend. In the demonstration example of this paper, there was evidence of a significant amount of curative migration between phases during the vulcanization process.
Recent Advances in Thermoplastic Elastomer Synthesis
Authors: Quirk Roderic P. , Kim Jungahn 
Published: February 2011

Abstract
A variety of living polymerization systems are now available for the controlled synthesis of block copolymers. Although living anionic polymerization remains as the method of choice for the most precise structural control, living polymerizations proceeding via other mechanistic types provide extremely useful extensions of this methodology to a wider variety of monomers.
Reflections on the Past and Future of Polyether Elastomers and on Redox Emulsion Polymerization
Authors: Vandenberg E. J. 
Published: February 2011

Abstract
I am greatly honored to have been selected to receive the prestigious Charles Goodyear Medal of the Rubber Division of the American Chemical Society. My work in the rubber field falls into two general areas: (1) early discoveries on the redox emulsion polymerization of styrene-butadiene rubber (SBR) and (2) polyether elastomers. I am perhaps best known for my work on polyether elastomers since I discovered, patented, and helped develop several families of polyether elastomers which were commercialized and are still important speciality elastomers. Most of my talk will be in that area. However, my SBR studies included my first important polymer-science discovery and preceded those who independently discovered the same systems and who were able to develop them commercially to the considerable advantage of our largest volume synthetic rubber, SBR. After briefly reviewing these past areas, I will give you my reflections on what important future developments for the rubber field could arise in the polyether area.
Synthesis of a Model Triblock for Novel Thermoplastic Elastomers
Authors: Verma A. , Nielsen A. , Mcgrath J. E. , Riffle J. S. 
Published: February 2011

Abstract
Thus far, we have been successful in preparing novel diblock and triblock copolymers comprised of poly(methyl methacrylate) and poly(butyl vinyl ether). Future work will focus on studying the morphology of both the diblock and triblock copolymers. Moreover, we are also interested in synthesizing triblocks with long poly(butyl vinyl ether) segments and short PMMA segments, since these polymers have the potential for exhibiting good elastomeric properties.
Laser Mass Spectral Investigations of Rubber Compound Surface Species
Authors: Waddell Walter H. , Benzing Kimberly A. , Evans Larry R. , Mowdood Syed K. , Weil David A. , McMahon John M. , Cody Robert H. , Kinsinger James A. 
Published: February 2011

Abstract
Laser desorption mass spectrometry has proven a uniquely useful technique for the direct characterization of rubber-compound surface species. Mass spectra were obtained for intact molecular ions (M+) of organic chemical rubber additives such as the aromatic processing oil, and the aromatic antiozonant and antioxidants incorporated to protect the rubber. Molecular-weight information from the molecular ions and structural information from the fragmentation ions could be obtained without interference from the fragmentation peaks of the rubber backbone. Rubber compounding ingredients were also characterized by LDMS techniques. Differences in the structure of two carbon blacks were apparent, based upon the relative intensities of the various peaks present such as the significantly higher m/z 26 peak thought to be due to CN− compared to the m/z 24 peak thought to be due to C2−, and the peaks resulting from the presence of hydrogen atom(s) on the carbon clusters for the high NSA and DBPA black. Laser and thermal desorption mass spectral techniques provided complementary structural information, and when coupled with current analytical methods to characterize rubber compounds, can provide the necessary information to positively identify various organic species present on the surfaces of vulcanized rubber.
Effect of Aspect Ratio on Tire Rolling Resistance
Authors: Pillai P. S. , Fielding-Russell G. S. 
Published: February 2011

Abstract
A simple equation has been developed for predicting changes in tire rolling resistance of similarly constructed tires when tire aspect ratio is varied. The equation is expressed in terms of tire parameters listed on the tire sidewall. The usefulness of the equation has been demonstrated by comparing predicted rolling resistance changes with actual changes using available data from a number of radial passenger tires.
Shear and Biaxial Extension Measurements of Reinforcement from in-situ Precipitated Silica
Authors: Wang Shuhong , Xu Ping , Mark James E. 
Published: February 2011

Abstract
Elastomeric networks were prepared by tetrafunctionally end-linking hydroxyl-terminated polydimethylsiloxane (PDMS) chains and were then filled by the in-situ precipitation of silica. The resulting networks were investigated in shear and biaxial extension. The method employed to produce large shears was to stretch a short, wide strip between two clamps. The deformation produced in this way is pure shear; simple shear was calculated directly from the pure-shear data. Biaxial extension measurements were carried out by inflation of circular sheets of the networks. Compared to the unfilled networks, the silica-filled samples showed large reinforcing effects. Specifically, their values of the modulus, ultimate strength, and rupture energy increase significantly. The results thus indicate that the PDMS networks filled by the in-situ precipitation of silica have good mechanical properties, not only in uniaxial elongation, but in shear and biaxial extension as well.
Morphology of Elastomeric Alloys
Authors: Abdou-Sabet Sabet , Patel Raman P. 
Published: February 2011

Abstract
The field of thermoplastic elastomers has shown an explosive growth with the successful commercialization of elastomeric alloys (EAs) in 1981, based on the original work of Coran, Das, and Patel on dynamic vulcanization and the discovery of preferred cure system by Abdou-Sabet and Fath. These discoveries have led to the development of commercial products having true elastomeric properties while maintaining excellent thermoplastic processing. The success of EAs in the marketplace has led to the introduction of new products by Monsanto and others at a rate of 60 products per year in the last half of the eighties. Elastomeric alloys have been characterized as compositions containing rubber particulate domains approximately 1–2 µm in diameter in a matrix of thermoplastic resin. Such dispersed phase morphology has not been widely accepted, especially when it came to explaining the true elastomeric properties of the soft elastomeric products, i.e. 64 and 55 Shore A hardness products. Interaction among the rubber particles leading to a network of vulcanized elastomer phase that gave the appearance of two continuous networks has been proposed. In this paper, the morphology of EPDM/polypropylene elastomeric alloys is examined with some detail, and evidence leading to dispersed phase morphology is provided. There are several variables to such an investigation which can be grouped under the following headings: 1. Molecular weight of EPDM and polypropylene (PP). 2. Ratio of EPDM to PP. 3. Crosslinked or uncrosslinked blend. 4. Degree of crosslinking. 5. Type of crosslinks. 6. Typical and commercial products. It is not the subject of this paper to review the morphology of different binary polymer blends, which have been extensively covered in the literature. It can be concluded that a variety of morphologies can be obtained, however, depending on the mixing conditions, polymer ratios, relative surface energies of the polymer pair, and viscosities and molecular weights of the two polymers. In this study, the mixing conditions were kept similar as much as possible to eliminate the possibility of morphological changes as a function of the applied mixing intensity as influenced by shear rate, mixing time, and temperature.
The Ozonation of N,N′-Di-n-Octyl-p-Phenylenediamine and N,N′-Di-(1,1-Dimethylethyl)-p-Phenylenediamine
Authors: Lattimer R. P. , Layer R. W. , Hooser E. R. , Rhee C. K. 
Published: February 2011

Abstract
Ozone attack on rubber compounds causes characteristic cracking perpendicular to the direction of applied stress. This degradation is caused by reaction of ozone with the double bonds in the rubber molecules. This causes chain scission and the formation of various decomposition products. The general subject of protection of rubber against ozone attack has been reviewed by a number of authors. In order to control the effects of rubber ozonation, either paraffin waxes or chemical antiozonants are added to unsaturated rubbers. The most effective antiozonants are N,N′-disubstituted-p-phenylenediamines (PPDAs), in which at least one of the side groups is alkyl (preferably sec-alkyl). Several theories have appeared in the literature regarding the mechanism of antiozonant protection. The “scavenger” model states that the antiozonant blooms to the surface and preferentially reacts with ozone so that the rubber is not attacked until the antiozonant is exhausted. The “protective film” theory is similar, except that the ozone-antiozonant reaction products form a film on the rubber surface that prevents (physically and perhaps chemically as well) ozone attack on the rubber. A third “relinking” theory states that the antiozonant prevents scission of the ozonized rubber or else recombines severed double bonds. A final theory states that the antiozonant reacts with the ozonized rubber or Criegee zwitterion (carbonyl oxide) to give a low-molecular-weight, inert, “self-healing” film on the rubber surface. Currently, the most accepted mechanism of antiozonant action is a combination of the scavenger and protective film theories.
Bulging of Rubber through Apertures
Authors: Gent A. N. , Kim W. 
Published: February 2011

Abstract
1. When rubber bulges through an aperture, the bulge height varies linearly with applied pressure. It also varies linearly with radius or width of the aperture when the dimensions of the rubber block are much larger than the aperture, in good agreement with linear elasticity theory. When the block is not much larger than the radius or width of the aperture, a simple empirical factor provides a satisfactory correction. 2. FEM results were in good agreement with experiment in all cases and confirmed the empirical correction for relatively large apertures. 3. Bulge profiles were calculated to be elliptical in all cases. 4. Results for an elastic solid are wholly consistent with Roscoe's results for a viscous liquid. 5. Changing slip conditions at the interface had a surprisingly small effect. The exact theory, Equations (5) and (7), is based upon a nonslip condition. When a fully lubricated condition was employed instead, so that free sliding was allowed at the interface, the maximum bulge heights predicted by FEM were only about 5% higher than before for a circular aperture and about 12% higher for a slit. Experimental observations of bulge heights with dry and lubricated interfaces were in good agreement with these predictions. 6. Bulge heights through small apertures provide a simple means of measuring pressure at contact surfaces.
Morphology of Carbon-Black Aggregates: Fractal Versus Euclidean Geometry
Authors: Herd Charles R. , McDonald Gerard C. , Hess William M. 
Published: February 2011

Abstract
A study has been made comparing the utility of fractal and Euclidean geometry in the characterization of carbon-black aggregates. The fractal models used were the perimeter-area relationship, P∼ADp/2, and the mass fractal, M∼RDm. Values of the perimeter fractal, Dp, and the mass fractal, Dm, were determined for nineteen different grades of carbon black from a sampling of 1000 aggregates per grade. The perimeter (P), area (A), mass (M), and size (R) of the aggregates were all measured by on-line transmission-electron-microscopy/automated-image-analysis (TEM/AIA) which enabled rapid sampling. Values of Dp and Dm ranged from 1.05 to 1.23 and 2.85 to 2.47 respectively and were shown to correlate with carbon-black colloidal properties such as dibutyl-phthalate absorption (DBPA) and Euclidean size and shape parameters from TEM/AIA. These parameters were also used to classify aggregates into different shape categories using discrimination analysis techniques. Both perimeter and mass fractals were nearly constant within each shape category. Four carbon blacks of similar particle size and varied DBPA range were also used to show the effects on Dp and Dm upon high-shear mixing of the carbon-black aggregates into rubber and CAB composites.
Fractal Dimension of Carbon-Black Particles
Authors: Zerda T. Waldek , Yang Henry , Gerspacher Michel 
Published: February 2011

Abstract
Fractal dimension of carbon-black particles is determined using adsorption technique. Gases of various surface areas are adsorbed on carbon-black samples of particle sizes varying from 20 nm to 100 nm, and it is shown that surface fractal dimension of the particles is about 2,2 and does not depend on the grade of carbon black.
A Viscohyperelastic Maxwell Model for Rubber Viscoelasticity
Authors: Johnson A. R. , Quigley C. J. 
Published: February 2011

Abstract
A new viscoelaslic model for rubber is presented. It is similar in a Maxwell internal solid model in which all the solids are hyperelastic. A key feature of this model is its ability to accurately predict step-strain relaxation test data for very large strains. A method to obtain the constitutive models for the solids is presented for the three legged version and is used with existing data in the literature to compute variable-rate uniaxial pull tests. The finite-element implementation of this theory is given. Computations are made for a uniaxial constant-strain-rate test using a nearly incompressible axisymmetric version of the finite-element method.
New Elastomers by Reactive Processing. Part II. Dynamic Vulcanization of Blends by Trans-Esterification
Authors: Coran A. Y. , Lee S. 
Published: February 2011

Abstract
The dynamic vulcanization of a rubbery acrylate copolymer (ACR) (the dispersed phase) during its mixing with NBR (the continuous phase) can produce a millable specialty elastomer alloy. The ACR polymer can be crosslinked even without having special molecular sites for vulcanization such as those of the conventional acrylate rubbers (ACM). This is possible because, under the conditions for dynamic vulcanization, the acrylate-derived ester groups themselves can be made to act as sites for vulcanization by using tin-catalyzed ester-interchange chemistry. The millable dynamic vulcanizate containing the crosslinked dispersed phase can be later mixed with curatives for the continuous phase, fillers, antidegradants, etc. and then be vulcanized (e.g., in a heated mold). Since the ACR can be completely vulcanized during the dynamic vulcanization stage of the mixing process, the usual postcuring associated with acrylate rubber (ACM) technology is not necessary. Excellent performance characteristics can be produced by using this technology.
Finite-Element Analysis of Laminated Rubber Bearing Used in Base-Isolation System
Authors: Takayama Mineo , Tada Hideyuki , Tanaka Ryuichi 
Published: February 2011

Abstract
A realistic mechanical model was proposed for the laminated rubber bearing, one of the most important structural members in the base-isolation system. The model was analyzed by means of the finite-element method (FEM), up to the range of large deformation under high compressive load. The physical characteristics of the rubber material was modeled using a strain-energy-density function based on the biaxial elongation tests. The load-deformation relationship calculated by FEM using such strain-energy-density function agreed well with experimental results. Based on the simulated stress and strain distributions in the laminated rubber bearing, a mechanism of supporting the vertical load during horizontal deformation was proposed.
Structure and Density of Crosslinks in Natural-Rubber Vulcanizates. A Combined Analysis by NMR Spectroscopy, Mechanical Measurements, and Rubber-Elastic Theory
Authors: Gronski Wolfram , Hoffmann Uwe , Simon Gerald , Wutzler Andre , Straube Ekkehard 
Published: February 2011

Abstract
13C-NMR MAS solid-state spectroscopy and 1H-NMR relaxation measurements have been applied for quantitative determination of crosslink density in sulfur-accelerated NR vulcanizates. It is shown that the 13C-NMR method is able to distinguish between monosulfidic crosslinks and polysulfldic structures; therefore a quantitative determination of chemical crosslinks was possible. An analysis of 13-NMR transversal relaxation measurements provided the network densities which were in good agreement with the results of the 13C-NMR measurements. Comparing stress-strain data with the spectroscopically determined crosslink density of the NR vulcanizates and calculated crosslink densities of peroxide-cured vulcanizates, it is shown that the same relation between low-strain modulus and crosslink density is valid independent of the structure of the vulcanizates. The chemical crosslink density determined by a theoretical approach based on the tube concept was in approximate agreement with the NMR results.