bluuebunny/crossref_metadata_2025_split huggingface dataset:
Deformational Behavior of Rubber in a Variable Speed “Mooney” Rheometer
Authors: Nakajima N. , Collins E. A. 
Published: February 2011

Abstract
Because the Mooney Rheometer is widely used and accepted in the laboratory and the plant a closer examination of what it measures is warranted. Although the steady torque value has been converted to steady-state viscosity, the “Mooney torque—time curve” has not been reduced to fundamental parameters. This work, carried out with SBR 1500, treats the initial torque rise as the shear stress-strain behavior analogous to tensile stress-strain. A master curve was constructed from such data obtained at various speeds using a principle of corresponding states. The master curve closely resembles the steady-state viscosity curve and at high shear rates joins the complex viscosity curve measured with the Rheovibron. In addition the use of the transient data enables one to extend the low shear end of the viscosity-rate curve by two decades. The peaks of the torque—time curves strongly suggest that they represent failure points of the material.
Molecular Structure and Macroscopic Properties of Synthetic Cis-Poly(Isoprene)
Authors: Grechanovskii V. A. , Poddubnyi I. Ya , Ivanova L. S. 
Published: February 2011

Abstract
By changing the sol-gel ratio and the structure of the gel fraction it is possible to obtain various grades of synthetic cis-poly(isoprene) which show promise for different applications in the tire and mechanical rubber goods industries. The processability of commercial SKI-3 rubber (at a given average molecular weight of sol) depends mainly on the structure of the gel fraction. Thus, for example, inferior processing properties of rubber compounds is associated primarily with the presence of tight gel. The content and structure of the gel fraction also significantly affect plasto-elastic properties of raw rubbers, e.g. a low plasticity of raw rubbers owes to the increased content of gel fraction. The reduced green strength of compounds based on SKI—3 rubber is accounted for by its chemical structure. Conventional methods used to change the properties of rubbers (including the variation in molecular weight, molecular weight distribution, branching degree, and variation in the content and structure of gel fraction) cannot be considered to be adequate to tackle the problem of the green strength of SKI—3 black stocks. The way to solve the problem appears to be the introduction of functional groups into the polymer chain at the stage of synthesis or processing. These functional groups should be active as to the formation of labile rubber—carbon black—rubber and/or rubber—rubber bonds. High purity of microstructure is necessary but not sufficient for obtaining the required level of green strength of compounded SKI—3. The gel fractions of SKI—3 rubber yield vulcanizates with a more dense network than the corresponding sol vulcanizates. The temperature dependence of the tensile strength is controlled by the network density of vulcanizates from high cis-1,4 poly(isoprene).
Study of Orientational Transformations of Supramolecular Structures on the Surfaces of Uniaxially Stretched Elastomers
Authors: Nel'son K. V. , Tkachenko G. T. , Ionina N. V. 
Published: February 2011

Abstract
Characteristics of surface orientation of cis poly(butadiene) elastomers with covalent crosslinks were studied with data from MPTIR ir spectroscopy and electron microscopy. It was shown that the supramolecular structures observed in electron photomicrographs of uniaxially stretched elastomer surfaces and their spatial reorganization correlate completely with changes in dichroism of a series of absorption bands in the MPTIR ir spectra. It was established that the maximal dichroism values in the MPTIR spectra correspond to orientation of coarse fibrillar forms, and the subsequent dichroism decline, corresponds to their deorientation. It was shown that, according to the extent of deorientation of the coarse fibrils, an increase in the cross section of the thin fibrils occurs with sharper margins separating them from the disordered part of the polymer; it was established by this that in the MPTIR spectra Rxy is partly increased, the intensity of a series of vibrations grows, and new absorption bands appear. The indicated facts are explained as due to intrafibrillar crystallization.
Heat Generation in Tires Due to the Viscoelastic Properties of Elastomeric Components
Authors: Willett P. R. 
Published: February 2011

Abstract
The relationship between the heat generation as experienced in the tire shoulder and the viscoelastic properties of the tire elastomeric components has been formulated. The analysis was facilitated by adopting the technique of multiple regression where the significance of each response equation was statistically evaluated. The physical intepretation and consequences of such response equations have been extensively discussed, whereas literature on the subject is incomplete. Effects of tire construction and size on the heat generation in the shoulder region was carried out by analyzing the results of tires that had reached a state of thermal equilibrium on an indoor tire-dynamometer. The tires used in the analysis were cross-ply and radial-ply passenger tires and cross-ply truck tires. Within the limits of such an analysis, the heat generation experienced in the tire shoulder was predominantly due to the condition classified as that of constant stress amplitude.
Short-Fiber—Rubber Composites: The Properties of Oriented Cellulose-Fiber—Elastomer Composites
Authors: Coran A. Y. , Boustany K. , Hamed P. 
Published: February 2011

Abstract
Unregenerated-cellulose-fiber-elastomer composites with widely varying properties can be obtained. The properties depend on the type of elastomer used as the matrix, the fiber concentration, fiber aspect ratio, and fiber orientation. The fibers must be bonded to the matrix elastomer to obtain good strength. Composites of good strength can be prepared from a wide variety of elastomers. Composites with Young's modulus from 20000 to over 100000 psi and strengths up to 6000 psi can be obtained by varying the amounts or lengths of fibers. In addition, these compositions offer a high degree of dimensional stability; they resist creep deformation and solvent swelling. Further, compositions of good fatigue life under high stress conditions can be obtained. It is expected that the new composite compositions will find uses where good long-term load-bearing characteristics and dimensional stability are required. Uses in a number of environments are indicated since a wide variety of elastomers can be used as matrix.
Cord—Rubber Adhesion. A Quantitative Shear—Adhesion Test
Authors: Skolnik L. 
Published: February 2011

Abstract
Three independent proofs have shown that the slightly modified “H” pull-out adhesion test is in fact a quantitative measure of the shear adhesion strength of the system. Some examples of the usefulness of this quantitative shear-adhesion test have been described. The use of the principles of the test for dynamic adhesion testing of products, such as tires, was also described.
Elastomer Blends
Authors: Corish P. J. , Powell B. D. W. 
Published: February 2011

Abstract
Mixtures are difficult to define within the range of materials employed in the rubber and plastic industries. A composite article such as a tire is a mixture of wire (metal), textile cord (organic fiber), and rubber compounds. The rubber compound itself is a mixture of elastomer, filler, and, usually, extender. Moreover, the elastomer may be a mixture of two or more rubbers. On a smaller scale, the elastomer may contain ‘blocky’ segments or crystalline portions along the polymer chains which act as ‘reinforcing’ agents or stiffeners. These may be similar to the repeat units of the elastomeric part, e.g., isotactic—atactic block copolymers of poly(propylene) or poly(propylene oxide); or different from it, as in the stereo block styrene—butadiene thermoplastic copolymers. Two types of elastomer may of course, be copolymerized or one elastomeric type may be grafted onto another. Furthermore, certain catalysts could cause simultaneous homopolymerization of two monomers. All the foregoing systems are different facets of the broad concept of blends, but some selection is obviously needed. In this review, most emphasis will be placed on elastomer—elastomer blends including their preparation from the constituent elastomers. Reference will be made to elastomer—plastic blends prepared from separate materials and by block/graft type reactions. Blends of one plastic with another lie outside the scope of this review.
Scrap Tire Disposal
Authors: Beckman J. A. , Crane G. , Kay E. L. , Laman J. R. 
Published: February 2011

Abstract
Our overall objective in presenting this review is to call attention to the very complicated nature of the entire disposal problem. The whole field of scrap-tire disposal is full of alternatives, compromises, legislation, and conflicting reports on technological success. We will present a brief historical section explaining why the disposal of scrap-tires is now a problem (challenge) and the events that lead to it. Statistics on the annual volume of scrap-rubber generated and the volume disposed of by major processes will be reviewed. Existing and proposed legislation will be presented, and the probable impact on the rubber industry discussed. We will state what we believe to be the characteristics of an ideal solution. The technical aspects of scrap-tire disposal will not be neglected. The physical, thermal, and chemical values of a scrap-tire will be presented as a basis of defining potential uses for scrap-tires. The existing and proposed uses of scrap-tires as well as processes for disposal are extremely varied. We have decided to discuss processes for scrap-tire disposal under three general categories: physical applications, recovery of fuel value, and chemical processes. Certainly there are processes which overlap these artificial categories. We have concentrated on literature published in the last five years as a means of updating the reader. Private communications are liberally referred to in our review simply because this is the only way some information is available. We have also concentrated on large-volume uses or processes which have the potential for large volume. These uses or processes may be an immediate solution. However, we have also endeavored to record or comment on all ideas for scrap-tire disposal. Finally, we have expressed our opinion as to future trends.
Direct Analog Simulation of Hysteretic Heat Buildup in Rubber
Authors: Claxton W. E. , Conant F. S. 
Published: February 2011

Abstract
An instrument has been constructed for real-time analog simulation of temperature rise in a rubber article subjected to periodic strains. In an illustrative application to a tire tread; the effects of changes in ambient temperature, degree of internal cooling, addition of frictional heating and changes in distribution of hysteretic heat were studied. The results were in general agreement with experience on actual tires. Some suggestions are given for modifications to the instrument to increase its validity and versatility.
Adaptation of the Rheovibron to the Measurement of Dynamic Properties of Vulcanizates at Elongations up to Sample Rupture
Authors: Voet A. , Morawski J. C. 
Published: February 2011

Abstract
The Rheovibron dynamic tester can be adapted to the measurement of dynamic properties of elastomers at high deformations, up to sample rupture. The method used is superimposing small sinusoidal oscillations on statically extended specimen. In order to obtain significant dynamic data it is necessary to determine the value of Kc exactly, the correction factor for instrumental displacements, as well Kv, to correct for the deformation of the part of the specimen held within the clamps. It appears that Kv is dependent on amplitude, frequency, temperature, and sample characteristics and must be determined for each sample at each imposed condition separately. At higher extensions Kv corrections assume a major ro^le in the measurements, greatly complicating the procedures. The method for calculation of the correction factors advanced by Massa for glassy polymers does not hold for elastomers. A novel specimen arrangement has been developed, resulting in a zero Kv correction, independent of amplitude, frequency or temperature. With elastomers the Kc correction is generally also zero, leading to greatly simplified measurements as well as to more accurate results. The temperature control system of the Rheovibron was modified to permit specimen temperatures in the range of − 70° to +120° C, either at programmed increases or decreases or at any constant temperature in the range. The movement of the extension clamp was motorized, to ensure a regular, reproducible motion.
Variable Shear Rate Viscosity of SBR-Filler-Plasticizer Systems
Authors: Derringer G. C. 
Published: February 2011

Abstract
Variable shear rate viscosity studies of compositions with variable filler and plasticizer levels have led to the development of a unifying viscosity model. Application of the model indicated that the fillers studied are less effective as stiffeners at shear rates typical of factory processing operations than at the low shear rates characteristic of the Mooney viscosity test. Thus, for proper comparative evaluations of pigment effect on processing, Mooney measurements are inadequate. The effect of shear rate on plasticizer efficiency will require more work to make definitive statements. Plasticizer evaluations appear to be a fruitful avenue for further exploration. The model developed has proved useful in understanding the individual contribution to the viscosity of the compound by the raw elastomer, the filler, and the plasticizer over a wide range of shear rates. The availability of this model will also result in an economy of experimentation as each shear rate of interest need not be studied separately. Having a valid model makes it possible to optimize the experimental design with regard to cost and information.
Secondary Treatment of Wastewater from Synthetic Rubber Production
Authors: Troppe F. G. 
Published: February 2011

Abstract
Secondary treatment of wastes generated from synthetic rubber production was studied for a nine-month period. Its design criteria were flow of 3.55 MGPD and effluent reductions of BOD by 90 per cent and suspended solids by 95 per cent to 7 mg/l and 10 mg/l respectively. Average reductions of 84.2 per cent for BOD and 85.2 per cent for suspended solids were achieved. The treatment processes included neutralization, coagulation, flocculation, primary clarification, biological treatment, final clarification, and sludge impoundment. Dissolved air flotation aids clarification while aeration provides biological treatment. Raw wastewater was characterized by the presence of salt brine, dilute acid wastes, boiler blowdown, dilute latex, and coagulated rubber solids. Influent concentrations were BOD 72 mg/l, COD 447 mg/l, suspended solids 197 mg/l. Of the total project cost in excess of $2,000,000, approximately 25 per cent was utilized to segregate process wastewater from storm water. The average costs for operation, maintenance, and depreciation were $0.50 per 1,000 gallons of wastewater treated.
The Role of Certain Organic Sulfur Compounds as Preventive Antioxidants
Authors: Shelton J. Reid 
Published: February 2011

Abstract
The mechanism of autoxidation of organic materials by elemental oxygen is a free radical chain reaction initiated by hydroperoxide decomposition to form alkoxy and peroxy radicals. Chain scission and crosslinking reactions occur, along with the formation of hydroperoxide, resulting in degradation of properties of polymeric materials. The presence of unsaturation in natural and synthetic rubbers makes them particularly vulnerable to autoxidation, and antioxidants are thus essential to provide protection against oxidative degradation. There are two ways in which antioxidants can function to retard autoxidation. Preventive antioxidants act in some way to reduce the rate of initiation, while chain-breaking antioxidants intercept the chain-propagating peroxy free radicals and thus terminate the chain mechanism. Both types include a variety of compounds and possible modes of action as indicated in the following classification:
Importance of Singlet Oxygen in the Degradation of Rubbers and Plastics
Authors: Carlsson D. J. , Wiles D. M. 
Published: February 2011

Abstract
Singlet oxygen attack on rubbers and poly(olefins) is likely to be significant in the presence of sensitizing impurities such as oxidation products, polynuclear aromatic pollutants, and many additives. 1O2 attack will yield hydroperoxide groups, and so markedly impair the subsequent heat and light stability of the materials. However stabilizer systems which have already been developed can be expected to protect against the effects of 1O2 by quenching to the relatively inoccuous 2O3 (ground state oxygen). For rubbers the aromatic amines widely employed as antizonants will protect against 1O2 attack, whereas the nickel chelates employed as uv stabilizers will protect poly(olefins).
Oxidation of Poly(Isoprene)
Authors: Morand J. L. 
Published: February 2011

Abstract
A Prussian Blue colorimetric method has been developed to determine the number of conjugated polyenes present in commercial elastomers. These groups disappear at the onset of oxidation of unvulcanized lithium-poly (isoprene) : their content decreases by about 50 per cent during the first hour heating at 100° C in air. Simultaneously, a great number of volatile oxidation products are formed since the early stage of aging. The major products, the concentrations of which increase throughout heating until oxidation is advanced, are presumably produced by random attack on the regular isoprene units. The present investigation has made it possible to isolate from this group of compounds 4-methyl-4-vinyl-butyrolactone and 4-hydroxy-2-butanone, previously unrecognized, in addition to levulinaldehyde, methacrolein, and methyl vinyl ketone previously identified by Bevilacqua. An attempt was made to explain their origin. In addition to the compounds just mentioned, minor products corresponding essentially to unsaturated aldehydes and esters were also obtained. They might arise from the decomposition of conjugated polyenes which disappear at the start of oxidation. They have not yet been collected in sufficient amounts to confirm their structures and more experimental work is required to establish the mechanism by which they are formed.
Segmental Diffusion in Rubbers Studied by Neutron Quasielastic Incoherent Scattering
Authors: Allen Geoffrey , Higgins J. S. , Wright C. J. 
Published: February 2011

Abstract
Neutron scattering experiments on polymethylphenylsiloxane, poly(propylene oxide), poly(isobutylene), and poly(ethylene oxide) show broadening in the quasi-elastic region similar to that previously reported from polydimethylsiloxane. Measurements on partially deuterated samples confirm that the effect arises from segmental diffusive motion, rather than rotations of pendent side groups. The temperature dependence of this motion gives activation energies which are smaller than the activation energies for self-diffusion obtained from experiments of longer time-scale such as nuclear spin-lattice relaxation measurements and viscometry.
13C Nuclear Magnetic Resonance Spectroscopy of Polydienes, Micro Structure of Poly(Butadiene)
Authors: Clague A. D. H. , van Broekhoven J. A. M. , Blaauw L. P. 
Published: February 2011

Abstract
13C nmr spectra have been recorded of several poly(butadiene)s and their hydrogenated analogs, with various amounts of 1,2 structure, but with a roughly constant ratio of cis-1,4 to trans-1,4 structures. From an assignment of these spectra a detailed picture has emerged of the sequence distribution of the cis- and trans-1,4 and the 1,2 units in the poly (butadiene) chain. It is shown that these units are distributed in an essentially random manner and that 1,2 units are head to tail incorporated.
Non-Relaxing Crack Growth and Fatigue in a Non-Crystallizing Rubber
Authors: Lindley P. B. 
Published: February 2011

Abstract
The crack growth behavior of a non-crystallizing rubber, SBR, is investigated in terms of the tearing energy T, the energy available for crack growth. For cyclic deformations in which the minimum tearing energy is zero (relaxing conditions), a unique relationship is obtained between the growth per cycle and T at the maximum deformation. This rubber also exhibits crack growth at constant tearing energies. The relationship of the crack growth rate as a function of tearing energy, when the minimum tearing energy of the cycle is not zero, can be superimposed on the relaxing relationship by scaling the rates, and a tentative explanation is proposed for the scaling factor. Fatigue data are consistent with this.
Surface Friction and Dynamic Mechanical Properties of Polymers
Authors: Bueche A. M. , Flom D. G. 
Published: February 2011

Abstract
Results are presented of experiments on the lubricated sliding of metals on polymers over a range of speeds and temperatures. These results indicate a correlation between the frictional behavior of materials and their bulk mechanical properties. Support for the experimental correlations is presented in the form of a theory relating the coefficient of rolling friction to bulk mechanical properties. The general conclusions may be expected to hold for metals as well as other materials. The theory may also be expected to apply to well lubricated sliding where shearing forces have been minimized. Under the conditions of lubrication most commonly encountered, the sliding friction is expected to be much more complicated; both the shear properties of the boundary layer and the hysteresis characteristics will be important.
The Role of Rubber Hysteresis in Skidding Resistance Measurements
Authors: Giles C. G. , Sabet Barbara E. 
Published: February 2011

Abstract
In this paper the authors have tried to give examples of some of the more important ways in which Dr. Tabor's paper on the importance of rubber hysteresis has contributed to a better understanding of the mechanism of friction between tire and road. It is evident that a number of the problems presented by past test results may now be explained in terms of rubber hysteresis losses, in particular, the mechanism of the dependence of skidding resistance on temperature, and the differences in performance between natural and synthetic tires. In relation to testing techniques it draws attention to the importance of temperature and to the need to standardize the hysteresis loss properties of test tires in addition to the hardness of tread-rubber. Finally, the most important of all, as Dr. Tabor suggests, his work opens up the possibility of improvements in tire characteristics, which could result in greatly increased friction coefficients and hence greater freedom from skidding under wet conditions. The limited full-scale tests the authors have been able to make seem fully to confirm this possibility.