bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Fatigue Resistant Polychloroprene Compound for High Temperature Dynamic Applications
Authors: Tabar R. J. , Killgoar P. C. , Pett R. A. 
Published: February 2011

Abstract
A polychloroprene material has been developed which can replace the natural rubber materials traditionally used in dynamic, fatigue-producing applications, when these applications require high temperature stability. An optimized compound based on a mercaptan modified polychloroprene with large particle high structure carbon black, silica filler and rapeseed oil has superior compression set, improved heat aged fatigue life and comparable dynamic properties to current NR compounds. This CR compound was designed to have good fatigue life while keeping compression set to a minimum. A positive correlation between tear resistance and fatigue life has been demonstrated for a series of CR compounds.
Interlaminar Shear Strain Measurements in Cord-Rubber Composites
Authors: Lou A. Y. C. , Walter J. D. 
Published: February 2011

Abstract
The present work is an experimental study using an X-ray technique to measure directly the internal distribution of interlaminar shear deformations which occur during uniaxial extension of two-ply, cord-rubber, angle-ply laminates—both balanced and unbalanced. Significant interlaminar shear strains were developed between the two generally orthotropic layers of one-inch-wide specimens, which decreased almost linearly from a maximum at the edges to zero at the center line. These measurements and those as a function of cord angle were in good agreement with predictions obtained from various theories of laminated shear-flexible composites.
New Developments in a Dynamic Wire Adhesion Test
Authors: Wagner M. P. , Hewitt N. L. 
Published: February 2011

Abstract
The performance of the rubber-wire belt in radial tires is, of course, critical to the safety of the tire. While initial adhesion between the rubber and the steel cord is important, the only meaningful adhesion is that retained during the dynamic life of the tire. This depends on the fatigue resistance of the rubber-cord composite, as well as the resistance to deterioration from hostile environments, such as heat, oxygen, and humidity. Static pullout, even after environmental aging, bears little relation to dynamic performance in tires. No dynamic adhesion test, short of tire testing, has had widespread use. In a previous publication a dynamic test for rubber-wire adhesion was described which appeared to relate to the tire performance of the rubber skim stock. This test has been further developed and evaluated in relation to tire performance. Additionally, the test has been used as a screening method to evaluate various additives in the rubber skim formulation.
A Surface Study of Ozone Attack and Antiozonant Protection of Carbon Black Loaded Natural Rubber Compounds
Authors: Andries J. C. A. , Rhee C. K. , Smith R. W. , Ross D. B. , Diem H. E. 
Published: February 2011

Abstract
This work reports a direct surface analysis of ozonization of carbon black loaded NR compounds by ATR and SEM. On ozonization of raw NR or NR containing carbon black, a thick layer builds up consisting of ozonides and carbonyl compounds. It is suggested that this layer is composed principally of the reaction products of ozone with unsaturated fatty acids and unsaturated fatty acid esters found in NR. On ozonization of cured and uncured carbon black loaded NR compounds containing curatives, the NR is attacked causing a decrease of rubber on the surface and a corresponding increase in the surface concentration of carbon black. The thick ozonide/carbonyl layer did not form, probably due to the coordination of the fatty acids and esters with ZnO, which was added with the curatives. On ozonization of carbon black-loaded NR compounds containing N,N′-dioctyl-p-phenylenediamine antiozonant, a continuous film is seen by SEM which has an ATR spectrum essentially identical to ozonized antiozonant. There is no evidence of ozonized NR products, or of complex reaction products between antiozonant and ozonized NR. These results are consistent with a dual scavenger and protective layer mechanism for antiozonant protection.
High Performance Nitrile Rubber Automotive Fuel Hose
Authors: Horvath James W. 
Published: February 2011

Abstract
The GM-6165M specification represents a significant upgrading of the performance of nitrile rubber based automotive fuel hose. Industry acceptance of this specification could lead to consolidation of hose types, and a cost saving if it displaces epichlorohydrin rubber. Compounding to meet the GM hose specification requires a departure from traditional carbon black formulations. A specific selection of each compound ingredient for its contribution to the total performance of the hose is necessary. Bound antioxidant nitrile rubbers are recognized by those who have seriously worked with them as superior performance polymers. Their service performance is unmatched by any other nitrile rubber in the applications which have developed for them in the Automotive Industry. They have consistently performed better than suggested by laboratory testing. This report demonstrates how to compound the 28% acrylonitrile Chemigum HR-765 to meet the severe requirements of GM-6165M.
Reinforcement of Uncured and Cured Rubber Composites and Its Relationship to Dispersive Mixing—An Interpretation of Cure Meter Rheographs of Carbon Black Loaded SBR and Cis-Polybutadiene Compounds
Authors: Lee B. L. 
Published: February 2011

Abstract
A new approach has been proposed to characterize the state of mixing of carbon black-loaded SBR and cis-polybutadiene compounds. The basic concept is that carbon black aggregates, present when the dispersion is imperfect, affect the modulus of the uncured compound more than that of the cured compound. From cure meter curves, the torque values before and after curing can be related to moduli which can, in turn, be analyzed to give information on the state of aggregation of the carbon black. An equation is proposed which correlates the relative modulus values with volume fraction of carbon black, morphology (packing or state of aggregation) of carbon black, and polymer-carbon black interaction.
Model Compound Vulcanization—Part III. The Relationships between Sulfidic Product Yield and Stress-Strain Properties
Authors: Lautenschlaeger F. K. 
Published: February 2011

Abstract
Twenty accelerators were compared by model compound vulcanization, (MCV). A relationship was established between total sulfidic product yield and tensile modulus (300%) of natural rubber vulcanizates. In previous work, two types of accelerators were distinguished by MCV on the basis of their distributions of the isomeric monosulfide reaction products. Type A accelerators consists of a wide range of functional compounds such as sulfenamides and guanidines. Type B accelerators contain a thiocarbamyl or a thiophosphate group. These Types of accelerators can also be distinguished on the basis of their relationship between sulfidic product yield in MCV and tensile modulus. The difference between these two Types of accelerators can also be derived from their relationship between tensile modulus and failure properties such as tear strength and tensile strength. Type A accelerators show a somewhat higher tear and tensile strength at a given tensile modulus value. The difference is attributed to the different distribution of sulfidic crosslinks, and possibly to chain scission in vulcanizates of Type B accelerators.
Peel Mechanics for an Elastic-Plastic Adherend
Authors: Gent A. N. , Hamed G. R. 
Published: February 2011

Abstract
The force required to propagate a 180° bend in an elastic-plastic strip has been calculated from elementary bending theory. Measured forces for Mylar strips of various thicknesses, bent to various degrees, were in good agreement with these calculated values. The corresponding additional stripping force in a peeling experiment will depend upon the thickness of the elastic-plastic adherend, becoming zero both for infinitesimally thin adherends and for those exceeding a critical thickness tc and passing through a maximum value at intermediate thicknesses. Published data are in good agreement with these conclusions. For a strongly adhering strip, higher peel strengths are found for a peel angle of 180°, compared to 90°, and the effect is greater than can be accounted for solely by plastic yielding of the adherend. It is attributed in part to greater energy dissipation within the adhesive layer.
Inflation Pressure Loss in Tubeless Tires—Effects of Tire Size, Service, and Construction
Authors: Coddington D. M. 
Published: February 2011

Abstract
Maintaining proper inflation pressure in tubeless tires, particularly radials, is critical to maximum tread wear life, durability, and minimum rolling resistance for vehicle fuel economy. This paper has discussed experimental studies of tubeless tire inflation pressure loss and how it is affected by tire size, operating pressure and temperature, and innerliner construction. Inflation pressure loss rates have been measured for varied commercial production tire constructions and sizes under static, constant temperature conditions. Pilot plant built radial passenger tires with varied innerliners have been tested for inflation loss rate, both statically and dynamically. A model equation has been developed to relate inflation pressure retention (IPR) to principal parameters of tire geometry, service and innerliner construction. Correlation of predicted air retention with actual performance is promising. A tire immersion test procedure has been employed to demonstrate air loss via migration and to study its paths. These studies indicate that properly fitted tubeless tires, free of mechanical leaks, can still have significant pressure loss via permeation; that the rate of loss increases as tire size is reduced; and that an ultra-low permeability innerliner can greatly improve tire inflation retention under static and dynamic service conditions.
Crosslinking and Mechanical Properties of Liquid Rubber. I. Curative Effect of Aliphatic DIOLS
Authors: Minoura Yuji , Yamashita Shinzo , Okamoto Hiroshi , Matsuo Tadao , Izawa Michiaki , Kohmoto Shun-Ich 
Published: February 2011

Abstract
The structure-property relationships of polyurethane elastomers derived from a liquid hydroxyl-terminated polybutadiene/low molecular weight aliphatic diol/diisocyanate system were studied. The effects of the amount of low molecular weight diol on the mechanical properties of the elastomer were discussed on the basis of the results of stress-strain, swelling, dynamic viscoelasticity, x-ray diffraction, etc. It was found that some particular combinations of low molecular weight diol and diisocyanate specifically affect the properties of elastomers. When the mechanical properties of the elastomers were plotted against the number of methylene carbons in the low molecular weight diol, characteristic zigzag patterns were obtained. These patterns were explained by the difference in the packing and the dependence of the strength of intermolecular hydrogen bonding on whether the number of the methylene carbons was even or odd. This assumption was confirmed by x-ray diffraction.
Mechanisms of Antioxidant Action: Rubber-Bound Antioxidants Based on Nitrones—I. Non-Sulphur Vulcanizates
Authors: Scott G. , Smith K. V. 
Published: February 2011

Abstract
The antioxidant activities of a number of N-phenyl nitrones containing phenolic functions were compared with N-methyl nitrones and conventional antioxidants in peroxide and TMTD sulphurless vulcanizates. The N-phenyl nitrones were found to be effectively bound during vulcanization; whereas, the N-methyl nitrones were not. Unhindered phenols reacted to a higher degree and were relatively more effective than the typical hindered phenol antioxidant structures. A conventional bisphenol was effective in the sulphurless vulcanizate after solvent extraction, but this is considered to be due to the formation of an insoluble zinc salt. Synergism was observed in the TMTD sulphurless vulcanizate both before and after extraction.
Complexities of Crosslink Density in Filled Elastomers
Authors: Polmanteer K. E. , Helmer J. D. 
Published: February 2011

Abstract
This work was undertaken to learn more about the complicated role of fillers in reinforcing siloxane polymers and attempt to clarify why silica fillers cause the crosslink density to increase significantly more in siloxane polymers than in hydrocarbon polymers. To carry out this study it was necessary to decide upon a method for determining the effective number of crosslinks. A simple mathematical expression applicable to both filled and unfilled elastomers was developed for use with a compression modulus technique for swollen vulcanizates. The fillers studied with polydimethylsiloxane (containing a small amount of methylvinylsiloxane) were a fume silica, wet process silica, diatomaceous earth, and two ground quartz silicas. The effect of concentration of network chains on tensile strength, modulus, and dynamic mechanical properties was compared for fume silica and diatomaceous earth filled stocks. All of the types of silica studied caused the crosslink density to increase several times over that of the unfilled vulcanizate. This may be contrasted with a factor of less than 2 for a filled (carbon black or silica filler) hydrocarbon polymer. The difference in behavior of the two polymer systems was attributed to a pronounced interaction between the siloxane polymer and the silica surface. The data indicated that filler structure has a more pronounced effect on crosslink density than surface area. It was found that the log of concentration of network chains gives a straight line when plotted as a function of volume fraction filler.
High-Performance Toluene Diisocyanate-Polypropylene Glycol Castable Elastoplastics
Authors: Berger S. Edmund , Szukiewicz Waclaw 
Published: February 2011

Abstract
This paper deals with relatively inexpensive castable polymers based on toluene diisocyanate and polypropylene glycol and having mechanical characteristics of both elastomers and plastics. Formulation changes that increase strength and hardness have an unfavorable effect on elasticity. Generally, the described polymers have better mechanical properties than similar known materials. Polymers produced by the one-shot method seem to exhibit better heat-aging properties than prepolymer-derived analogs. A range of applications is suggested.
Reaction between Cumyl Peroxide and Butyl Rubbers
Authors: Loan L. D. 
Published: February 2011

Abstract
The reaction between cumyl peroxide and butyl rubbers has been followed by means of molecular weight measurements. In all cases except that of the rubber with highest unsaturation the molecular weight falls, and the scission efficiency of the peroxide is found to depend quite markedly upon the unsaturation. For the rubber of highest unsaturation a small overall crosslinking reaction was observed. The results are interpreted as showing that cumyloxy radicals react with isoprene units in the chain about 300 times as fast as with isobutylene units. The molecular weight dependence on time during the reaction has been investigated but has not been satisfactorily explained.
Vulcanization of Elastomers. 40. Vulcanization of Natural Rubber and Synthetic Rubber with Sulfur in Presence of Sulfenamides. III
Authors: Scheele W. , Helberg J. 
Published: February 2011

Abstract
Vulcanization of natural rubber with sulfur was studied in presence of six sulfenamides, to determine the effect of the chemical constitution of the sulfenamide on sulfur decrease and on crosslinking. The results can be condensed as follows: (1) The kinetics of sulfur disappearance is in every respect qualitatively independent of the chemical constitution of the sulfenamide. (2) For the sulfenamides investigated, the smallest and largest rate constants for sulfur decrease differed only by a factor of two. (3) Greater differences are encountered in the induction times for sulfur decrease and for crosslinking. The latter are notably longer than those for sulfur disappearance. (4) The same activation energy, 23 kcal/mole, is derived from the temperature dependence of the induction times for all the sulfenamides. (5) The dissociation of sulfenamides in solution and their reaction with mercaptobenzothiazole were investigated further. The results provide the basis for a proposed reaction mechanism, which is presented in detail and can account for a number of the features typical of sulfenamide-accelerated vulcanization. (6) The drop in sulfur concentration goes at practically the same rate, if one introduces, instead of N, N-dicyclohexyl-2-benzothiazolesulfenamide, the corresponding ammonium mercaptide in equimolar concentration.
Reactions of Accelerators of Vulcanization with Rubbers of Different Structures
Authors: Dogadkin B. A. , Feldshtein M. S. , Belyaeva E. N. 
Published: February 2011

Abstract
Reactivities of various rubbers (SKB, SKS-30 and NR) were studied at vulcanization temperatures, employing MBTS, CBS and sulfur as vulcanizing agents. The systems, rubber plus accelerator, and rubber plus accelerator plus sulfur were subjected to such temperatures. Reactivities of the rubbers were determined by measuring the degree of dehydrogenation indicated by formation of MBT. Reactivities were also determined by the addition of RS⋅ radicals to polymer chains, the variation in maxima of gelling and the kinetics of addition of elementary sulfur. Dehydrogenation resulting from addition of accelerator radicals to polymer chains in the rubbers assumed the following order: SKB &gt; SKS-30 &gt; NR. Reactivity of elementary sulfur to rubbers, in the presence of the accelerators employed, assumed the reverse order; NR &gt; SKS-30 &gt; SKB. The differences in the reactivities of the various rubbers is associated with the peculiarities of their structures.
Consequences and Development of an Invention
Authors: Ziegler Karl 
Published: February 2011

Abstract
The awarding of the Nobel Prize for Chemistry, for the year 1963, is related to the precipitous expansion of macromolecular chemistry and its industrial applications, which began precisely ten years ago at my Max-Planck-Institute for Coal Research, in Mülheim/Ruhr. The suddenness with which this began, and the rapidity with which it was propagated are comparable to an explosion. The energy sources in this case were the ingenuity, activity, creative imagination and bold concepts of the many unnamed chemists, designers and entrepreneurs in the world who have fashioned great industries from our humble beginnings. If today I stand with my colleague Natta, who has been particularly effective in promoting this explosive wave, in the limelight of distinction, and do wish to manifest, with this address, my appreciation for the honor bestowed upon me, I must begin by thanking these many anonymous persons. They, too, deserve this distinction. The extent of this “explosion” may be illustrated by two charts, in which the location of newly-established plants is indicated. The places marked by black circles refer to new production facilities which, though concerned with low molecular weight materials, nevertheless also have some connection with the address I am delivering today (Figures 1 and 2). The new development had its inception near the end of 1953, when I, together with Holzkamp, Breil and Martin observed, for several days, an almost dramatic occurrence: that ethylene gas will polymerize very rapidly with certain catalysts that are extremely easy to prepare, at 100, 20 and 5 atmospheres and, finally, even at normal pressure, to a high molecular weight plastic.
Spherulite Morphology in Thin Films of Natural Rubber
Authors: Andrews E. H. 
Published: February 2011

Abstract
Crystalline ‘spherulites’ grown in ultra-thin films of natural rubber at − 26° C were examined in the electron microscope. The spherulites form hollow domes, like blisters in the film, which collapse under electron irradiation producing remarkable fiber-like patterns of folds and creases. Within the spherulite, crystalline and amorphous regions coexist and the former appear to grow to a preferred thickness of a few hundred angstroms with the molecular chains oriented perpendicular to the film. The molecules are thus almost certainly folded as in polymer single crystals grown from dilute solution. Electron diffraction data suggest that relatively large regions of the spherulite correspond to single crystals. A growth mechanism for the spherulites is proposed.
From Stereospecific Polymerization to Asymmetric Autocatalytic Synthesis of Macromolecules
Authors: Natta Giulio 
Published: February 2011

Abstract
Macromolecular chemistry is a relatively young science. Though natural and synthetic macromolecular substances had long been known, it was only between 1920 and 1930 that Hermann Staudinger placed our knowledge of the chemical structure of several macromolecular substances on a scientific basis. In the wake of Staudinger's discoveries and hypotheses, macromolecular chemistry has made considerable progress. Very many synthetic macromolecular substances were prepared both by polymerization and by polycondensation; methods were found for the regulation of the value and distribution of molecular weights; attempts were made to clarify the relationships existing among structure, chemical regularity, molecular weight, and physical and technological properties of the macromolecular substances. It was far more difficult to obtain synthetic macromolecules having a regular structure both from the chemical and steric point of view. An early result in this field, which aroused a certain interest in relation to elastomers, was the preparation of a polybutadiene having a very high content of trans-1,4 monomeric units, in the presence of heterogeneous catalysts. A wider development of this field was made possible by the recent discovery of stereospecific polymerization. This led to the synthesis of sterically regular polymers as well as to that of new classes of crystalline polymers.
Crystalline Morphology in Thin Films of Natural Rubber: Crystallization under Strain
Authors: Andrews E. H. 
Published: February 2011

Abstract
The morphology of thin films of natural rubber crystallized under unidirectional strain has been examined in the electron microscope. As strain increases the spherulitic morphology of unstrained films gives way gradually to a fibrillar morphology with crystalline filaments (α filaments) measuring 60 by 250 A˚, growing perpendicular to the strain axis. The nucleation of these filaments is governed by the amount of strain but their rate of growth depends only on temperature and time. At very high strains (&gt;300%) crystallization occurs rapidly allowing no time for filament growth, so that the resulting morphology consists of chains of nuclei (γ filaments) running in the direction of extension. The high strain transition from α to γ filaments is accompanied by no change in the electron diffraction pattern, but the earlier transition from spherulitic to filamentous growth reveals a rotation of the molecular axis into the direction of strain. This appears to correspond to a physical rotation of the α filaments about their direction of growth.