bluuebunny/crossref_metadata_2025_split huggingface dataset:
Surface Properties of Carbon
Authors: Rivin Donald 
Published: February 2011

Abstract
Carbon surface chemistry is relatively new as an independent subject of inquiry, and, judging by the volume of publications, is receiving increasing attention throughout the world. Our conception of carbon black and its functional behavior has changed significantly since the pioneering publication by Studebaker in 1957. Within the last few years there have been a number of excellent reviews covering various aspects of carbon chemistry by authors who are presently active in this field. Donnet, Puri, and Boehm discuss reactions of carbon and the characterization of surface functional groups while van der Plas is particularly thorough on the subject of adsorption properties and porosity. Deviney explores the relationship between surface chemistry and carbon-elastomer interactions, as does Studebaker from the point of view of the practical application of carbon black in rubber. Current monographs containing useful background information are collected in “Les Carbones” and in Walker's continuing series, “Chemistry and Physics of Carbon”. This review will describe how information from diverse sources has contributed to our understanding of the surface reactivity and fundamental adsorption behavior of carbon. It will be shown that most properties of carbon blacks are consistent with a surface structure wherein large deformed basal layers conforming to the topography of the surface are composed of several planar aromatic domains with functional groups at edge and defect sites. Examples of strong molecular interactions are given which involve specific reaction with the basal surface, individual functional groups, or a combination of both.
Tire Temperatures
Authors: Conant F. S. 
Published: February 2011

Abstract
Tire operating temperature is of vital concern to tire engineers because it relates to both service life and power loss in a tire. It may also affect performance in areas such as traction and cornering ability. Operating temperature is a limiting factor in the choice of construction material for truck tires, which run at much higher temperatures than do automobile tires. Adhesion failures are generally believed to be caused by excessive heat. Yet White was unable to produce separation by heat alone, even though he held a tire at 300° F for two hours, then tried to pull the components apart. In high speed operations the high temperature developed may weaken the ply bonds in a tire, which can then be separated by a combination of centrifugal force and fatigue. If the temperature reaches 350 to 400° F, however, tire separations will occur before fatigue type failures are evident. In fact, a rough relationship has been established between attained tire temperature and the type of failure in road tests. Failures more directly related to fatigue are also hastened by high temperatures. Natural rubber softens or reverts, while SBR tends to harden and become brittle under the same conditions. With the exception of groove cracking a typical fatigue failure starts from an inhomogeneity as a small internal crack and grows by heat and mechanical action. The torn surfaces usually rub against each other to cause heat degradation. In this case heat is the result rather than the cause of failure. Tread sections lying at the side of superhighways are evidence that the tires from which they came were overworked. Temperature build-up restricts use of thicker treads, of longer wearing high-grip tread compounds, and the speed potential of any tire. Tread wear is sharply reduced by an increase in temperature, whether ambient or work-induced. So many tire properties are adversely affected by high temperature that heat has been called the great enemy of tires. The two principal purposes of this review are to examine some of the causes and results of tire temperature build-up and to discuss some of the methods which have been used to measure or compute temperatures in various tire regions.
Infrared Determination of Composition of Ethylene-Propylene Copolymers
Authors: Gardner I. J. , Cozewith C. , Strate G. Ver 
Published: February 2011

Abstract
Carbon-14 labeled ethylene and propylene were used to synthesize a series of copolymers of known composition to serve as standards for copolymer analyses. Polymers with broad and narrow compositional distributions and differing sequence distributions were produced by varying the catalyst system. Solution and combustion counting techniques were used to determine sample composition and then infrared calibration curves were determined on pressed polymer films utilizing several different infrared peaks. 1. Within the ranges systematically varied neither compositional nor sequence distributions affect the peak ratios studied. 2. No isotope effects exist in the polymerizations. 3. NMR analysis yields the same results as 14C analysis. 4. Use of the 1378 cm−1 methyl band as calibrated with atactic polypropylene yields agreement with the 14C data if the average of polypropylene and copolymer results is used. 5. We amend the results previously published by our laboratory.
Compounding EPDM for Dynamics Applications
Authors: Hazelton D. R. , Puydak R. C. 
Published: February 2011

Abstract
To conclude, the simplest and least costly approach to EPDM compounds for most dynamics mountings is EPDM filled primarily with FEF black and a medium viscosity naphthenic oil, and cured with a conventional sulfur system. The key to a successful compound, however, is the ratio and amount of black and oil used.
New Accelerators for Blends of EPDM
Authors: Mastromatteo R. P. , Mitchell J. M. , Brett T. J. 
Published: February 2011

Abstract
Through the use of accelerators containing higher alkyl substitution, we have been able to attain improved properties of EPDM diene rubber blends. EPDM/NBR blends vulcanized with sulfur cure systems employing these accelerators compete favorably with CR compounds in heat aging; have essentially the same oil resistance level, and exhibit better low temperature properties. These blends are highly ozone resistant, easy processing, and safe. Because of the versatility of meeting a desired combination of properties by variations both in the ratios of NBR to EPDM and in the selection of the particular grade of each elastomer, these blends will fulfill many sophisticated elastomer applications. These accelerators can also be used to provide non-blooming cure systems for EPDM compounds and safer ultrafast cure systems for diene rubber compounds. We feel that this advance in property improvement in diene rubber EPDM blends through the use of these new accelerators is only the beginning of a whole new compounding technique for blending.
Silane Coupling Agent Effects in Ethylene Propylene Diene Terpolymers
Authors: Ranney M. W. , Pagano C. A. 
Published: February 2011

Abstract
The special performance properties noted for silane coupling agents in mineral filled EPDM compounds result from the interfacial effects related to the dual function reaction of the organofunctional silane. When common alkoxy substituted vinyl silanes are used, the nature of the hydrolyzable groups on the silicon atom is generally not a critical factor with adequate silane-filler bonding occurring under a variety of silane application techniques. It has been shown that to obtain optimum performance, the organofunctional group in the silane monomer must be generally reactive with the cure system being used, and have the ability to interact with the elastomer through co-polymerization or addition. It has been further shown that in the case of the copolymerizable vinyl silane (A-172) only a relatively low level of peroxide-induced vinyl silane-rubber bonding is obtained using standard levels of peroxide. Increasing the peroxide level in these vinyl silane-containing formulations results in a considerably higher level of filler-elastomer reinforcement producing dramatic improvements in modulus, tensile, and tear properties when compared with appropriate controls. In general, an enhanced utilization of silane at the elastomer-filler interface is realized. The use of the mercaptosilane (A-189) in sulfur curing mineral filled EPDM compounds improves the normal physical properties while dynamic testing also shows improvements in flex-life, abrasion, heat build-up, and road wear properties.
Rubber Chemicals from Cyclic Amines. IV. Thiocarbamyl Amine Disulfide Curing Agents
Authors: Morita E. , D'Amico J. J. 
Published: February 2011

Abstract
The cure properties of thiocarbamyl amine disulfide (I) as vulcanizing agents are influenced by the ionic and steric nature of both R and R′. The relative effects of various R and R′ are analogous to those of R and R′ in thiuram disulfides and dithioamines, respectively. However, the cure properties of I are dominated by the type of R rather than R′. Among the types of R investigated relatively longer scorch delay, slower cure rate and lower crosslink density are obtained, when R is morpholino or 3-azabicyclo(3.2.2)non-3-yl.
Rubber Chemicals from Cyclic Amines. VI. 2-(4-Morpholinodithio)Benzothiazole and Related Compounds as Curing Agents
Authors: D'Amico J. J. , Morita E. 
Published: February 2011

Abstract
Unlike the case of the thiazolesulfenamides, the electronic effect of substitution in the thiazole moiety on the curing properties of these compounds is not consistent. The unsubstituted 2-(4-morpholinodithio)benzothiazole 1 is superior to the 6-ethoxy, 5-chloro, or 6-nitro substituted derivatives in curing properties. The 5-ethoxycarbonyl-2-(morpholinodithio)-4-methylthiazole is comparable to 1 in scorch delay and curing activities. It is superior to the 5-acetyl and the unsubstituted 4-methyl thiazole derivatives. Both the benzoxazole and benzimidazole derivatives are inferior to the benzothiazole and 4-methyl thiazole analogs.
The Tensile Strength of Glass Yarn in Rubber and the Effects of Moisture. I
Authors: Gregg R. A. 
Published: February 2011

Abstract
The strength of glass tire yarn depends on its environment so that testing in rubber is necessary to determine the strength of the yarn as used. The techniques described for building and testing glass yarn-rubber composites lead to tensile values of good precision. The techniques allow specification of a standard tensile in rubber for a glass yarn. Tensiles which would exist under non-standard conditions experienced in manufacturing or use can also be determined. Tire operating temperature is one use condition covered. The techniques discriminate sufficiently to show the effects of small differences in moisture level on hot tensile strength. The rubber stock used here did not harm the tensile strength of the glass yarn. The observed tensile strength increase of the glass yarn encased in rubber as compared to air can be attributed to the stress transfer ability of the rubber and to the test piece configuration. The strength of a glass yarn-rubber composite is inversely related to the level of moisture in the composite. High moisture levels in the glass yarn and rubber stock at building and cure can hurt tensile since moisture loss from the composite can be slow. Also, high moisture level at cure may degrade the resin-adhesive system of some yarns. For this particular glass yarn under high humidity, storage at advanced temperatures and/or curing into rubber permanently damages the yarn. These observations were made under absolute humidity levels not usually encountered. The question of the extent of the humidity degradation of this type of glass yarn under practical humidities will be examined. Since the tensile loss is probably due to some degradative action on the sizing or resin, it cannot be assumed that all glass yarns will behave similarly. It will be necessary to determine the susceptibility of each glass yarn to moisture.
Research for a Uniform Quality Grading System for Tires V. Effect of Environment on Tread Wear Rate
Authors: Brenner F. C. , Kondo A. , Cohen G. B. 
Published: February 2011

Abstract
In tests with bias ply, belted bias, and radial commercial passenger car tires it was found that the rate of wear does not change as the tires are worn. It was also shown in a test which there were dry and wet periods that the same tires wore at a faster rate in the wet than in the dry. This observation was reinforced when a comparison of two tests run with duplicate sets of tires in January and June on the same course gave greatly different results; the greater rate of wear occurring in January when the course was continuously wet. Finally an explanation for the observation that tires wear faster on wet pavements has been proposed. The tire is more deformed passing through the contact patch on a wet surface than on a dry. In addition, the water, acting as a lubricant, reduces resistance to motion between surfaces of the cut rubber or the surface of the cutting asperity and the rubber.
Research for a Uniform Quality Grading System for Tires VI. Comparison of the Effect of Front and Rear Wheel Drive Vehicles on Projected Tread Wear of a Tire
Authors: Kondo A. , Brenner F. C. 
Published: February 2011

Abstract
The total number of miles that could be expected for a tire was projected and compared from a test involving two vehicles, one with a front axle drive and one with a rear axle drive. On the front axle drive vehicle the tires when changed by forward-X pattern each 1000 miles wore at twice the rate on the front wheels as on the rear; on the other vehicle they wore at about the same rate on both sets of wheels. The projected mileages for the tires on the two vehicles were 22,400 and 22,500 miles which is not appreciably different.
New Thermoplastic Elastomers. Styrene Grafts on Lithiated Polydienes and Their Hydrogenated Counterparts
Authors: Falk J. C. , Schlott R. J. , Hoeg D. F. , Pendleton J. F. 
Published: February 2011

Abstract
Metalation of diene polymers such as poly (butadiene) and poly(isoprene) with sec-butyllithium and tetramethylethylenediamine in cyclohexane at room temperature forms lithiated polydienes. Reaction of the polylithiodienes with styrene or α-methylstyrene forms graft copolymers. The extent of metalation is much greater than previously reported metalations with n-butyllithium and tetramethylethylenediamine. The grafting efficiencies, determined by acetone extraction and gel permeation chromatography, are greater than 95 per cent. Graft copolymers of poly (styrene) on EPDM rubbers may also be prepared using this technique. The physical properties of the graft copolymers are a function of molecular weight, graft site level, and composition. Products at specific compositions and graft levels are thermoplastic elastomers. Their properties are comparable to SBS rubbers, and offer as an advantage high melt flow. Graft copolymers of poly(styrene) on poly(ethylene) and poly(ethylene-co-butene-1) result from the hydrogenation of the butadiene moeities of graft copolymers of poly (styrene) on 1,4-poly(butadiene) and 1,2 and 1,4-butadiene copolymers, respectively. Complete hydrogenation results in graft copolymers of poly(vinylcyclohexane) on poly(ethylene) and on poly(ethylene-co-butene-1). In both of these cases thermoplastic elastomers result if the proper choice of composition and graft level is made.
Preparation and Properties of Polydienes
Authors: Saltman W. M. , Kuzma L. J. 
Published: February 2011

Abstract
In summary there are presented some new data on the initiation step for poly-(butadiene) polymerization with the AlEt3-Ni-BF3 catalyst which describe what appears to be a “settling down” period of newborn chains at the π-bonded nickel catalyst site. This leads to a segment of higher trans content at the end of each high cis-1,4-poly(butadiene) chain. Comparisons between nickel and cobalt catalysts seem to point up their differences rather than their similarities. We have described the role of water in effectively changing the identity of the aluminum alkyl which in turn has a marked effect on the polymerization rate, on the polymer molecular weight and the extent of crosslinking.
Measurement of Creep
Authors: Livingston D. I. , Fielding-Russell G. S. 
Published: February 2011

Abstract
We have described a multistation apparatus which greatly facilitates the measurement of creep and, by extending the range to shorter times, reduces the total time of the measurements. This apparatus is presently being connected to a computer and will then operate on an increasingly automatic basis. All weights will be lowered at once, the stations automatically sampled, and much of the computation performed. We shall also attempt to extend the measurements to even shorter times and thereby to reduce the number of temperatures necessary to construct the master curve. We have illustrated the operation of the apparatus with typical measurements on a crosslinked SBR sample. While the experiments may be confined to the linear region of viscoelasticity by the use of transducers of lower range and greater sensitivity, we chose to operate at extensions which made it necessary to use the Mooney-Rivlin equation to describe the results. Treatment of the data by the Mooney-Rivlin equation and reduction of the constants to a reference temperature gave a value for C1r whieh was independent of time and temperature. Within the experimental error, all the time dependence, except at very low temperature, was contained in C2r. Several other rubbers have shown similar behavior. The separation of behavior into a substantially elastic and a substantially viscoelastic part has thought-provoking implications.
Precision Treadwear Measurements at Increased Mileages by an Improved Radioiodine Method
Authors: Patel A. C. , Deviney M. L. 
Published: February 2011

Abstract
A greatly improved method for using Iodine-125 is described—one which permits precise, rapid, and convenient measurements of treadwear during road tests of considerably greater mileage (up to 1500–2000 miles) than reported by earlier workers. A highly reproducible laboratory calibration procedure has been developed and very close agreement between calibration curves and actual road test data is demonstrated for automobile tires in four specific treadstock cases: SBR, SBR/BR, NR, and NR/BR. Only a small percentage of the tread surface is tagged with I-125, which is employed at very low activity levels. The tagging procedure has been modified for much greater I-125 tread penetration, and has been simplified, shortened, and standardized for use by ordinary tire test personnel. It is also applicable to non-tire rubber products.
Accelerated Tire Wear under Controlled Conditions. II. Some Factors that Influence Tire Wear
Authors: Veith A. G. 
Published: February 2011

Abstract
Using the test system described in (I), we have determined the effect of some of the important factors in tire wear. There are three primary factors: tire force, pavement texture, and tire surface temperature. The major factor of these three is the sustained or instantaneous tire force. Accelerometer measurements show that cornering or lateral forces are chiefly responsible for wear in contrast to longitudinal (driving and braking) forces and the test system is designed to operate on the basis of such cornering forces. The wear rate depends exponentially on tire cornering force. In the low-moderate tire force range (0–500 lbs.) this may vary from approximately 2 to 4. The exponent depends upon pavement texture, tire temperature, and tread composition. Pavement texture is important in two ways: in the actual rate of wear produced and in the influence on mechanism of wear which is reflected by the value of the above mentioned exponent. Harsh aggregate pavements produce a faster rate of wear than smoother, blunt aggregate pavements. Harsh pavements give exponents of 2.0 to 2.5 which indicate a tensile-tear mechanism; blunt pavements give exponents of 3.5 to 4.0 which indicate a fatigue mechanism. The relative rating of tread compounds can change, including outright reversals, depending upon the pavement texture. The effects of such weather factors as rain are outlined. Rain “on the pavement” lowers wear rate but the “after-effect” of rain is different. The abrasiveness of pavements after a rain increases due to chemical surface etching and this promotes increased wear until the polishing action of traffic reduces this increased abrasive character. Tire surface temperature influences absolute wear rate and compound relative rating. Our data confirm the positive temperature coefficients reported by Schalla-mach. For current tread compounds, wear rate increases approximately 2% per degree Celsius. Tread composition is important. Carbon black colloidal properties, such as structure and tint, have a marked effect on tread compound wear resistance. At low tire force these effects are minimal; at high tire force, however, high structure and tint impart significant resistance to wear. This increased resistance can be quantitatively expressed by the “Severity Index Gradient”. The correlation of accelerated test results and fleet tests is, in general, good; but, due to the overall complexity of wear behavior, tire force levels, as well as pavement texture and tire temperature, must be taken into account in correlation calculations. Otherwise, confusing results will be obtained. It is precisely this ability to vary the three primary wear factors independently that makes this particular approach to tire wear important.
Elastic Modulus of Vulcanizates as Related to Carbon Black Structure
Authors: Medalia A. I. 
Published: February 2011

Abstract
The elastic modulus Gf′ of filled SBR vulcanizates has been measured as a function of strain amplitude A. At low loadings of carbon black (20 phr), where Gf′ is practically independent of A, the value of Gf′ (at 25° C, 0.25 Hz) can be predicted within 5 per eent from the gum modulus Gg′ by the Guth—Gold equation with due allowance for occluded volume, as calculated from the dibutyl phthalate absorption. At normal loadings (50 phr) the value of Gf′ can be predicted fairly well from this treatment if the measurements are made at high amplitude. At 25° C, 0.25 Hz, Gf′ is about 10 per cent higher than predicted due to the residual effect of the carbon black network. The dependence of the high-amplitude Gf′ on frequency and temperature is essentially the same for various reinforcing and semi-reinforcing blacks. Consequently, the value of Gf′ for one black can be calculated from the values found for other blacks. The dependence of Gf′ on A is primarily a function of surface area, but in two cases the dependence is unusually steep for different reasons. With graphitized blacks the low-amplitude Gf′ is higher than that of the ungraphitized blacks, but the high-amplitude Gf′ is low, probably due to molecular slippage. “New technology” blacks, including N339 and N351, give a high-amplitude Gf′ comparable to that of conventional blacks of the same dibutyl phthalate absorption, but give a higher Gf′ at low amplitude, indicating a more effective network structure.
Filler Effect on the Heat Stability of Vulcanized Elastomeric Compositions
Authors: Fetterman M. Q. 
Published: February 2011

Abstract
The purpose of this study was to determine filler effects on heat stability of vulcanized elastomeric compositions. Carbon-black reinforced compounds, designed to have good heat resistance, were modified by substituting hydrated silica for all or part of the black. Since a simple replacement of silica for black would result in dissimilar original properties, the substituted compounds were further revised to minimize this dissimilarity. This was accomplished through curative correction and/or addition of an organosilane coupling agent. Silica substitution did not provide permanency of properties at elevated temperatures, but in all cases the serviceable life of the compound was extended. Since silica substitution had minimum effect on other properties and reduced the rate of degradation at elevated temperature, this may be considered a reasonable alternative to completely redesigning a proven rubber compound in order to improve its heat resistance.