bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Third Dimension of Carbon Black Structure
Authors: Mercer H. N. , Boyer A. H. , Bhusky P. L. , Deviney M. L. 
Published: February 2011

Abstract
Structure is probably the most difficult characteristic of carbon black to define. Electron microscopy has shown that the individual particles of a black are fused together into a variety of shapes, collectively defined as the structure. Here, particle is used to refer to that entity which is somewhat spherical in shape and is the smallest “building block” of structure. These particles have also been called “domains” of rotational graphitic layers and “nodules”. The larger unit resulting from the fusion of these particles forms an “aggregate” or a “primary structure” unit. A collection of aggregates, held together by some other force (e.g , van der Waals force), is called an “agglomerate” or “secondary structure”. With dry black, it is difficult to completely eliminate all secondry structure. However, main emphasis in this study was on primary structure, because it has the greater influence on rubber properties and because secondary structure is greatly reduced in good rubber mixing. Many recent characterization studies have been concerned with making direct measurements on primary structure units (aggregates) by automated image analysis techniques, a pencil following device, and a comparative chart method. In the work described here, a different approach has been taken to viewing carbon black primary structure units, an approach using the scanning electron microscope combined with stereoscopic methods. This initial report will be mainly concerned with a description of the techniques and results on several individual primary structure units. It is suggested that the efforts described here provide a realistic view of carbon black primary structure and that a third dimension term is essential for primary structure characterization.
Radial Tire Cord-Rubber Composites
Authors: Patel H. P. , Turner J. L. , Walter J. D. 
Published: February 2011

Abstract
Experimental and theoretical results are presented in terms of the elements of the compliance matrix for the material properties which are needed to characterize a calendered ply of various cord-rubber composites commonly used in the body and belt of radial tires. It is shown that a single ply can be represented as a linear, elastic, homogeneous, orthotropic material to a level of accuracy sufficient for modeling inflated, but otherwise unloaded, radial tires. Cord load distributions in the body, belt, and turnup ply endings are predicted and plotted from the bead to the crown of inflated radial tires using principles of structural mechanics to represent the laminated material properties of the tire and finite element techniques to calculate the stresses in the cords. Predictions are also made for rubber strains and tire growth at the crown due to inflation pressure loading. The effects of changing various tire construction and/or material property parameters on such responses are assessed; these predictions are shown to be in reasonable agreement with experimental measurements.
Elongation of Painted High-Modulus Elastomers at Low Temperatures
Authors: Djiauw L. K. , Fesko D. G. 
Published: February 2011

Abstract
The paint film thickness and its elongation strongly affect the ultimate elongation of a painted elastomer. Thus, it is of utmost importance, in testing these materials, whether for component design or for material development, that the thickness of the paint be known and controlled. It is also important to note whether multiple cracks are present. Further, although low-temperature elastomers may display relatively high elongations even in the presence of paint cracks, elastomeric paints with greater low-temperature elongations are needed for available substrates to sustain higher deformations.
Studies of Heat Generation in Polyester Cord Tires
Authors: Lamb G. E. R. , Weigmann H-D. , Goswami B. C. 
Published: February 2011

Abstract
Measurements of loss factor in polyester cord and cured rubber stock were made. From the results, the equilibrium cord temperatures in a rotating tire were estimated. These calculated values agree with measured values reported in the literature. It is shown that, for truck tires, cord temperatures can easily rise to levels where cord degradation in the presence of sulfenamide accelerators is known to occur. Measurements on cords which had been degraded by aminolysis indicate that loss factors increase as a result of the degradation and cause significant increases in local steady-state temperatures. This effect will tend to accelerate the rate of degradation at those locations. The increases in loss factor agree with observations on loss factors at increasing levels of crystallinity in polyester fibers in the literature.
Mechanical Properties of Short-Fiber-Elastomer Composites
Authors: Moghe S. R. 
Published: February 2011

Abstract
The reinforcement of rubber compounds with short fibers has, at times, become necessary in many product applications. Particularly compounds with relatively low fiber content have proven successful in improving hose and belt performance. This is mostly due to an increase in composite stiffness without a great sacrifice of basic processability characteristics of the compound. Too large a fiber content becomes a primary source of difficulties during manufacture and/or product performance. Therefore, an understanding of how various composite properties depend upon fiber and matrix properties, as well as on fabrication methods, will help design better products. The mechanical properties, such as modulus, strength, and ultimate elongation depend upon fiber orientation, aspect ratio, and adhesion between fiber and matrix compound. Unfortunately, the degree and type of adhesion cannot be estimated quantitatively at present even though its importance in the improvement of composite properties is well recognized. Aspect ratio is another parameter which can be used in improving composite properties. As a rule, a higher aspect ratio gives higher composite stiffness. During processing, fibers are buckled and crimped under large deformations, which results in a distribution of fiber lengths, rather than a constant length as before mixing, as shown, for example, in Figure 1. One can, therefore, expect to achieve the same composite properties regardless of the initial fiber length (up to, say, 15 mm) or fiber length distribution. Of the three parameters, fiber orientation affects composite properties the most. During processing (milling, extrusion, etc.) of rubber composites, the fibers tend to orient along the flow direction, causing mechanical properties to vary in different directions. Therefore, by changing or suitably controlling the flow direction, optimum properties can be generated for a given product. A good example is the balanced fiber orientation in a hose which gives optimum design strength. Milling or calendering is perhaps the most commonly used processing method in which fibers tend to orient along the mill direction. Since each mill or calender differs from any other in size, roll speed, and other characteristics, it is essential to determine the influence of these parameters on composite properties. Results of a systematic study to identify significant mill parameters which influence the composite properties are presented here.
A Broad-Line NMR Investigation of Isoprene Rubber Filled with Carbon Black
Authors: Svensson L. G. , Svanson S. E. 
Published: February 2011

Abstract
The results of NMR measurements on IR filled with various carbon blacks lead to the following conclusions. The rubber matrix is a heterogeneous system characterized by two rubber phases of different chain mobilities. One phase is almost similar to unfilled IR at the temperature of measurement, while the properties of the other are nearly identical to those of pure IR at a lower temperature. The following observations apply to the phase with restricted mobility : 1. The quantities of rubber and carbon black in this phase are proportional below a critical loading, which supports the assumption that immobilization is limited to the immediate surroundings of the filler aggregates. The critical loading varies with structure and defines the packing density above which the formation of a coherent gel becomes important. 2. The rubber content decreases with rising temperature, showing that the activation energy for the onset of segmental motion varies within the phase. The mobility of the rubber chains directly bound to the surface is restricted even far above the glass transition temperature. 3. The degree of immobilization varies with temperature but is mostly independent of carbon black type and loading. 4. The actual distribution of immobilized rubber within an aggregate is not completely known, but some evidence exists for the immobilization of a thin surface layer as well as parts of the occluded rubber. A considerable immobilized rubber fraction is independent of surface area and structure.
A New Derivation of Postgel Properties of Network Polymers
Authors: Miller D. R. , Macosko C. W. 
Published: February 2011

Abstract
The probability of a finite or dangling chain on an ideal polymer network has been derived by a simple recursive scheme. In contrast to the method of Dobson and Gordon, probability generating function formalism is not required. The general result, Equations (21), and its specific solutions, Equations (23), (24), and (30), give the finite chain probability as a function of reactant type and extent of polymerization. They cover most of the important types of network forming polymerizations. From the finite chain probability, useful property relations such as sol fraction, crosslink density, and the number of elastically effective network chains are developed. Because of their simplicity, we expect these relations to be further developed and applied to network polymer property measurements.
The Effect of Network Structure in the Equation of Rubber Elasticity
Authors: Valles E. M. , Macosko C. W. 
Published: February 2011

Abstract
Though the stress, strain, and temperature dependence for an ideal rubber is fairly well established, the relation between network structural features like crosslinks, dangling ends, and entanglements and mechanical response is uncertain. The modulus-structure relations recently derived by Miller and Macosko for several types of networks are tested here with a model system: the hydrosilation crosslinking of vinyl-terminated polydimethylsiloxane chains with a tetra-functional silane. Results of shear modulus as a function of extent of reaction and of stoichiometric imbalance are in good agreement with the theory.
Randomly Branched Polymers. I. Hydrodynamic Properties
Authors: Kurata M. , Abe M. , Iwama M. , Matsushima M. 
Published: February 2011

Abstract
A sample of copolymer of styrene and 1,4-divinyl-2,3,5,6-tetrachloro-benzene was prepared and fractionated. Using the fractionated copolymers, effects of chain branching on the intrinsic viscosity and sedimentation coefficient were studied experimentally. It was found that in both theta and good solvents, the intrinsic viscosity of the branched polymers obeyed a new semi-empirical relationship, [η]b=g0.6[η]l. Here [η]l is the intrinsic viscosity of a linear polymer having the same molecular weight as the branched one, and g is the contraction factor which is defined as the ratio of the mean-square radii of gyration between the branched and linear polymers, i.e., g=〈S2〉b/〈S2〉l. It was also found that the sedimentation coefficient in theta solvent agreed with the theoretical value obtained by Kurata and Fukatsu. The degree of branching estimated from the intrinsic viscosity or sedimentation coefficient was in close agreement with the value estimated from consideration of the copolymerization kinetics.
The Structure and Relaxation of Thin Polymer Layers on Solid Surfaces
Authors: Lipatov Y. S. 
Published: February 2011

Abstract
In conclusion, we can say that the properties of thin polymer films and their relaxation behavior are strongly dependent on their thickness. This is related to the restriction of molecular mobility at the phase boundary (independent of its nature) as a result of the reduced number of possible chain conformations. The less the polymer thickness, the more pronounced is the contribution of surface layers with diminished molecular mobility to the mechanical properties. This statement may be illustrated by Figure 12, which shows the dependence of the elastic modulus and surface-to-volume ratio on film thickness. Diminishing film thickness leads to increase in film rigidity, beginning at the point where the surface-to-volume ratio increases sharply. This suggests that the effect is associated with change in mechanical properties of thin surface layers, which contributes significantly to total mechanical properties. We have other data which show also that the relaxation spectrum of a film is changed when its thickness changes. The findings discussed above indicate that the solid surface has a noticeable and complex effect on the properties and relaxation behavior and relaxation time spectra of polymer coatings on solid surface, both inorganic and organic. The principal reasons for these changes are the adsorption interaction with the solid surface, decrease of molecular mobility, and strong intermolecular interaction transferring the influence of the solid surface to more remote layers of polymer.
Solvent Crack Growth in NBR Rubber
Authors: Nakashima K. , Manabe K. 
Published: February 2011

Abstract
The solvent crack growth of rubber compounded with various carbon blacks or calcium carbonate was investigated. It was found that the rate of crack growth of filler-loaded rubber was linearly related to extension ratio in a manner similar to gum vulcanizates. The rate of crack growth passes through a minimum as the filler loading is increased. It is dependent on the particle size of the filler; smaller particles show much greater effect than coarser ones. When the rates of crack growth of highly loaded samples were plotted against the extension ratio, plots consisting of two straight lines with a bending point were obtained. It was found that the extension ratio at the bending point depended upon the loading and particle size of filler. It was a linear function of the square root of the distance between filler particles. The slope of the line above the bending point varies with type of filler: with carbon black the slope is steeper; with calcium carbonate it is less steep.
Recent Developments in Urethane Elastomers and Reaction Injection Molded (RIM) Elastomers
Authors: Frisch K. C. 
Published: February 2011

Abstract
The chemistry and technology of urethane elastomers has advanced rapidly since their inception in Europe in the late 1930'a and early 1940's. The earliest elastomers were Vulkollan, developed by I. G. Farbenindustrie (IGF) and Vulcaprene, developed by Imperial Chemical Industries (ICI). IGF developed a casting process for Vulkollan, while the processing of Vulcaprene was carried out on conventional rubber equipment. While these elastomers were crosslinked, new types of urethane elastomers were developed which were thermoplastic in nature and allowed processing by means of conventional thermoplastic processing equipment. Urethane elastomers were also developed in various other forms such as latices, solutions in organic solvents, poromeric sheets, spandex fibers, sealants and caulks (consisting generally of low modulus elastomers), and expanded or micro-cellular elastomers. Omitting spandex fibers and poromerics, urethane elastomers can be classified according to the method of processing by which they are produced:
Measurement of Rubber Cutting Resistance in the Absence of Friction
Authors: Lake G. J. , Yeoh O. H. 
Published: February 2011

Abstract
A method for assessing the resistance of rubbers to cutting by sharp objects is described. It involves the application of the cutting implement—a razor blade—to the tip of a crack in a stretched tear test piece. The method enables effects of friction on the cutting process to be substantially eliminated. Under these conditions two distinct forms of cutting are observed : one is a slow time-dependent process, while the other involves rapid, “catastrophic” failure. Effects of test piece shape and deformation on the cutting behavior can be taken into account by use of fracture mechanics. The relative cutting resistance of different rubbers is found to vary according to the test conditions. At low deformations the onset of catastrophic cutting can be defined by a simple relationship applicable to all rubbers examined.
Model Compound Vulcanization—Part V. The Effect of Chemical Additives and Fillers
Authors: Lautenschlaeger F. K. , Edwards K. 
Published: February 2011

Abstract
The effect of chemical additives and fillers on the yield and distribution of sulfidic products in model compound vulcanization (MCV) reactions was studied. Several controversial issues were resolved, and a better understanding of the effect of chemical additives on the physical properties of natural rubber vulcanizates has resulted. Additives considered as radical scavengers can increase or decrease the yield of products which correspond to crosslinks. The effect of peroxide depends on the type of accelerator; it is significant with thiuram disulfide acceleration, but negligible with sulfenamide acceleration. The product distribution from an organic dialkyl tetra-sulfide as a sulfur donor is shown. An inorganic disulfide, such as molybdenum disulfide, does not take part in the sulfur vulcanization. An analysis of the effect of fillers on the yield and distribution of those sulfidic products which correspond to crosslinks, and on the sulfidic byproducts was carried out. A similar detailed analysis cannot be achieved in vulcanizates. It was shown that the yield and distribution are significantly affected by inorganic and mineral fillers. MCV was applied to the analysis of the effect of silane coupling agents. Their beneficial effect on the yield and distribution of sulfidic products was shown. The yield of sulfidic byproducts is highest with fumed silica. An equivalent state of cure in filler-containing model vulcanizates should be established by accelerator activator and sulfur variations prior to the evaluation of fillers in the vulcanizates. This would enable a more direct evaluation of fillers, since their chemical and physical effects on the vulcanizate properties would be separable.
Interaction of Silica with Functionalized SBR
Authors: Edwards D. C. , Sato Kyosaku 
Published: February 2011

Abstract
In the absence of chemical interaction between precipitated silica and styrene-butadiene rubber, reticulation of silica particles occurs in the unvulcanized mixture and produces a stiffening effect. This process occurs gradually at room temperature and very rapidly at curing temperatures. The effect can be quantified conveniently by measuring the Young's modulus of raw compounds. SBR functionalized with a small concentration of hydroxyl groups, introduced by terpolymerization, can interact with precipitated silica particles by esterification. This reaction can be accelerated by catalysts. When carried out under conditions of combined heat and shear, this interaction prevents silica reticulation and produces vulcanizates with greatly altered and improved elastic properties. The present paper describes and illustrates these effects with reference to simplified compound recipes.
Low Temperature Dynamic Properties of Bitumin-Rubber Mixtures
Authors: Shim-Ton J. , Kennedy K. A. , Piggott M. R. , Woodhams R. T. 
Published: February 2011

Abstract
The influence of four different elastomeric materials on the low temperature dynamic properties of bitumen was determined using a Rheovibron Viscoelastometer. The four elastomeric materials included two waste products and two liquid rubbers : powdered vulcanized tire reclaim rubber, precipitated waste SBR latex from an effluent recovery system, liquid carboxy-terminated butadiene-co-acrylonitrile polymer (Goodrich CTBN), and liquid polybutadiene with terminal allylic bromine substituents (Polysar Liquid RTV Polymer). The results of the evaluation indicate that liquid polybutadiene is the most efficient low temperature flexibilizer, as might be expected from its low second order transition temperature (−85°C). A comparison of the penetration of the rubber-bitumen mixtures with the Brookfield viscosity reveals that the addition of rubber markedly reduces the temperature susceptibility. Attempts were also made to follow the thickening behavior of bitumen/ CTBN rubber mixtures after the addition of calcium hydroxide. The large increase in viscosity immediately following the addition of calcium hydroxide was followed by a gradual return to a slightly lower viscosity than the original bitumen-rubber mixture. The implications of the low temperature dynamic transitions, viscosity behavior, penetration values and thickening behavior of bitumen/rubber mixtures with respect to road performance are discussed.
Bromine Terminated Liquid Polybutadiene as a Solventless, Room-Temperature Adhesive System
Authors: Koshute M. A. , Stephens H. L. 
Published: February 2011

Abstract
This study involved the determination of the work of adhesion (Wa) to separate neoprene rubber from structural steel, using different formulations of room temperature cured dibromobutadiene (DBBD) as the adhesive system. The Wa of both the metal-to-adhesive (M-A) and rubber-to-adhesive (R-A) interface was determined by 180° peel tests at constant rate and temperature. The results of this investigation have shown that the level of adhesion can be controlled through the formulation of DBBD with different ratios of the curing agent MPEHA. The work of adhesion was found to increase with increasing crosslink density, but eventually reached a maximum value at an optimum crosslink density or molecular weight between crosslinks. Formulations containing an optimum level of the accelerator lead dimethyl-dithiocarbamate (Ledate) and organosilane coupling agent Z-6032 had a synergistic effect on the system. This optimum formulation was cured in 3 days and yielded values of Wa for the R-A interface equivalent to the 7-day cured optimum system of DBBD/MPEHA containing no additives, and increased the value of Wa for the M-A interface. The work of adhesion for the optimum system was found to increase with adhesive layer thickness, but obtained a maximum value at an optimum thickness. Cyclization was determined to be the best treatment of the neoprene surface to increase the Wa at the R-A interface. Testing of the optimum adhesive system at temperatures significantly lower than room temperature showed an increase in Wa at the R-A interface but no change at the M-A interface. However, testing at temperatures significantly higher than ambient yielded lower Wa values at both interfaces. The work of adhesion of the optimum adhesive system dropped significantly after 22 hours of water immersion. Further work should be carried out to increase the work life of the formulated adhesive and the hydrolytic stability of the total system.