bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of Carbon Black on Ultimate Properties of Rubber Vulcanizates
Authors: Medalia Avrom I. 
Published: February 2011

Abstract
In this survey, we have concluded that carbon black reinforces ultimate properties of rubber by tear deviation. This can occur at the colloidal level, as the tear is forced to pass around carbon black aggregates, thus increasing the area of the torn surface. Colloidal tear deviation may be the cause of the increase in threshold tearing energy which appears to be a small but significant component of reinforcement. Most reinforcement under ordinary test conditions is due to macroscopic tear deviation. This appears to be caused by strands of carbon black aggregates which force the growing tear to change direction. Macroscopic tear deviation is readily observed in a trouser tear test as stick-slip or knotty tear. In the tensile strength test, tear deviation prevents catastrophic rupture until a high stress is reached. In order to be effective in this or other ultimate properties, the carbon black must not debond; i.e., failure must go through the rubber rather than through the debonded rubber—filler interface. Reinforcing carbon blacks do not debond (from diene rubbers) under normal conditions and so do not require further strengthening of the rubber—filler bonds.
Viscoelastic Response and Adhesion Properties of Highly Filled Elastomers
Authors: Stacer R. G. , Husband D. M. , Stacer H. L. 
Published: February 2011

Abstract
The viscoelastic response of four highly-filled elastomers has been investigated. Small deformation dynamic testing of these materials reveals thay they are nonlinear viscoelastic, as well as thermorheologically complex. Nonlinear viscoelastic behavior was observed as a pronounced strain dependence in the range of 0.1 to 10%. The degree of this nonlinear response was quantified through a constitutive equation containing a single nonlinear factor; resultant nonlinear factors for the various materials were compared and evaluated. Thermorheologically complex behavior was displayed by slightly different shift coefficients to superpose G'′ and G″ data. An approach for calculating material resilience from the viscoelastic data was also developed and a nomographic technique presented for its application. A composite adhesive joint, consisting of two layers of a filled NBR compound bonded together by a filled putty interlayer, was also studied. It was found that both the adhesive fracture energy and the effect of interlayer thickness could be related to the loss modulus of the putty interlayer. Finally, the effect of contact time on bond strength was evaluated and results presented as a master curve of adhesive fracture energy vs. temperature-reduced contact time.
Solid State Carbon-13 NMR Studies of Vulcanized Elastomers. II, Sulfur Vulcanization of Natural Rubber
Authors: Zaper A. M. , Koenig J. L. 
Published: February 2011

Abstract
In summary, the solid-state C-13 NMR technique has proven to be a significant method for the detection of crosslinks and other structural modifications in sulfur-vulcanized NR systems. The use of sulfur as a crosslinking agent by itself generates a considerable amount of main-chain structural modifications. Cyclic sulfide structures and cis-to-trans chain isomerization are detected in addition to polysulfidic crosslinks which are found attached to different carbons of the NR repeat unit. The phenomenon of reversion has also been detected in this study. The nature of the spectral broadening in the NMR spectra of the highly cured vulcanizates has two origins. The broadening arises from lack of molecular motion in the system and from an increase in chemical shift dispersion due to the new structures formed with crosslinking.
Thermoplastic Elastomers
Authors: Legge Norman R. 
Published: February 2011

Abstract
It is a great pleasure to return to Montreal to receive the Charles Goodyear Medal at this joint meeting of the American Chemical Society, Rubber Division, and the Rubber Chemistry Division, Chemical Institute of Canada. This occasion has given me a delightful opportunity to renew old friendships in both organizations and to visit again my graduate school at McGill. First of all, I thank the Awards Committee and the Executive Committee of the Rubber Division for electing me to this high honor which I share with my many collaborators who were with me during those exciting years, and with the Shell Companies. The subject of the lecture is “Thermoplastic Elastomers,” specifically the triblock copolymers based on styrene and dienes, or hydrogenated dienes. Previously I have used the subtitle, “A Successful Innovation,” where I have defined “innovation” as the successful commercialization of a new technology, process, or product. In this lecture, I shall discuss the background of the innovation, the impact of it upon the thermoplastic elastomer field, and some of the early history of thermoplastic elastomers, which I believe you will find interesting.
Magnesium Silicate Filler in Rubber Tread Compounds
Authors: Hernández Luis González , Ibarra Rueda Luis M. , Antón Celia Chamorro 
Published: February 2011

Abstract
The natural magnesium silicate, sepiolite (trade name Pansil), can partially substitute (up to 30%) for carbon black without important losses in physical properties and occasionally can improve them. In the NR-based compounds, as the substitution takes place, vulcanization times and Mooney viscosities decrease. Tear and abrasion resistances are lower. The same effects are observed in the SBR-based compounds, though in this case, the addition of a silane coupling agent (Silane A-189) counteracts the negative effects of the sepiolite, and the obtained values are clearly better than those with only carbon black. According to tan δ behavior in truck tire tread compounds, this filler type gives a higher wet grip resistance, but rolling resistance would be adversely affected by its use, though the presence of a silane coupling agent diminishes these effects. On the contrary, in passenger tire tread compounds, the partial substitution for carbon black seems to increase the wet resistance too, without a pronounced damage in rolling resistance. In this case, the addition of the silane coupling agent produces an increase in wet skid resistance and a decrease in rolling resistance. Based on laboratory tests, rolling resistance increases in all cases, mainly when the sepiolite was modified with silane. Wet skid resistance showed no variations. Clearly, it would be desirable to confirm our observations by an actual tire test.
Viscoelastic Properties of Nylon 6 and Nylon 66 Tire Cords: Morphological Analysis
Authors: Prevorsek D. C. , Murthy S. , Kwon Y. D. 
Published: February 2011

Abstract
The differences in the viscoelastic properties of conditioned nylon 6 and nylon 66 cords leading to higher shoulder temperatures of nylon 66 tires are reviewed and analyzed in terms of fiber structure. It is concluded that these differences are related to the differences in crystallographic behavior of the two polymers. The conclusions are based on the viscoelastic data from tire cords removed from tires and the properties recorded after mechanical conditioning to reach steady state equivalent to driving conditions. Viscoelastic data are obtained with the Allied high-strain viscoelastomer and structural interpretations are based on SAXS and WAXS analyses.
Techniques for Observing Microfailure in the Aramid-Adhesive-Rubber Interface
Authors: Begnoche B. C. , Keefe R. L. , Causa A. G. 
Published: February 2011

Abstract
A variety of techniques were developed or investigated which were useful in pinpointing microfailure locations and determining failure mechanisms at the aramid fiber-adhesive-rubber interfaces. All of the techniques were microscopy related. The scanning electron microscope was the most useful tool, especially in the seldom used backscattered electron mode, when its variety of add-on options were employed, and support techniques were developed. Optical incident-light fluorescence microscopy used in the medical field proved to be a valuable supplement to the SEM, allowing verification of the microfailure mode when used on the same samples.
Comparison of Tensile and Shear Behavior of Carbon-Black-Filled Elastomers
Authors: Nakajima N. , Scobbo J. J. , Harrell E. R. 
Published: February 2011

Abstract
Four NBR's and 2 SBR's with 40 phr carbon black and one SBR with 56 phr carbon black were characterized in both tensile stress-strain behavior and small-strain dynamic-shear behavior. The room temperature tensile stress-strain behavior was determined at strain rates of 0.00690, 0.0187, 0.0975, 0.0162, and 0.253 s−1. For dynamic-shear observations, loss and storage moduli were used to calculate the complex viscosity-frequency curve at small deformations and frequencies of 0.1 to 100 rad/s. Also, these data from tensile and shear experiments were compared with previous data from a capillary rheometer, high-speed tensile tester, and oscillatory tensile tester. Strain-time correspondence was found applicable to large-deformation tensile data up to the yield point. The formation of an anisotropic aggregate density in elongational deformation explains the higher viscosity and modulus for tensile behavior relative to small-strain shear behavior at similar conditions. In shear deformation and flow, the formation of an anisotropic density of aggregates does not seem to occur appreciably.
Cure Adhesion in the Interface of Fluorinated and Nitrile Rubbers
Authors: Mori Kunio 
Published: February 2011

Abstract
Recently there has been a great deal of interest in new composite rubbery materials. Good properties require the reinforcement of the interfacial region which is formed between different rubbers. In order to strengthen the interfacial region, it is necessary to increase the thickness of the interfacial layer and the intermolecular forces. However, in a laminate and blends of rubbers with physically and chemically different properties, it is often very difficult to obtain this as, for example, in the case of fluorinated (FR) and nitrile (NBR) rubbers. This work indicates newly developed vulcanization systems which are very effective in producing FR-NBR composite materials with very good properties, because they induce interpolymer interactions.
Dynamic Testing under Nonsinusoidal Conditions and the Consequences of Nonlinearity for Service Performance
Authors: Harris J. A. 
Published: February 2011

Abstract
In this work, nonlinearity in the dynamic behavior of rubber has been considered. In order to understand its effects in a service environment involving complex patterns of vibration, it has been necessary to clarify the derivations of dynamic properties for the sinusoidal excitation that is conventionally used in testing. Using the fundamental frequency components as a basis, non-linearity can be quantified by the harmonic components that it produces. A dynamic test system has been developed which incorporates the ability to perform a harmonic analysis, and the usefulness of this has been demonstrated. Harmonic analysis has enabled the dynamic behavior of rubber to be quantified under complex, periodic waveforms. This is necessary for filled rubbers, because their nonlinearity means that a superposition on their properties from sinusoidal tests is incorrect. Examples of this approach for assessing dynamic behavior range from shock mounts to tire treads. Dual-sine tests on a nonlinear rubber indicate that for complex vibrations, consisting of many amplitudes and frequencies, the overall dynamic behavior will tend toward that obtained in single sine tests at a strain amplitude which corresponds to the largest amplitude that occurs in the time history. A similar conclusion is drawn from random vibration tests with a continuous spectrum of vibrations. The result of this is that under a more complex system of vibrations, nonlinear rubbers will behave in a more linear fashion and will exhibit higher damping than indicated by their dynamic properties measured in conventional sinusoidal tests. Therefore, when the service environment of many components is taken into account, the dynamic behavior of nonlinear rubbers may give better performance characteristics than expected from conventional testing.
Strain Amplification of Elastomers Filled with Carbon Black in Tensile Deformation
Authors: Nakajima N. , Scobbo J. J. 
Published: February 2011

Abstract
This work is based on data previously obtained by the tensile stress-strain and dynamic-shear measurements with several gum rubbers and carbon-black-filled compounds. The gum rubbers were three NBR's of different molecular architecture and two SBR's, one of which was oil extended. The compounds contained 40 phr of N550 carbon black. Through the data treatment procedure developed in this work, the strain amplifications in the dynamic shear and tensile stress-strain measurements were evaluated with the uncrosslinked compounds. Each compound showed a unique pattern of strain amplification.
Stabilized Curative Blends for Rubber
Authors: Sommer J. G. 
Published: February 2011

Abstract
Blending of curatives offers several advantages. These include a sharply reduced number of weighings of curative ingredients, reduced weighing costs, reduced dusting and improved cleanliness. These advantages might not be realized with some curative blends. For example, diphenyl guanidine (DPG) could not be blended with sulfenamide accelerators because it reacted chemically with the sulfenamides. Later work assessed the effect of 2-mercaptobenzothiazole (MBT), sulfur (S), or free amine on the hydrolytic stability of N-cyclohexyl-2-benzothiazyl-sulfenamide (CBS) that was highly purified. Results showed that free amine or sulfur accelerate the hydrolysis, but to a lesser extent than MBT. The present work shows that aging of curative blends (like S, CBS, and DPG) sharply reduces the scorch resistance of rubber compounds containing the aged blends. Selected additives will stabilize the blends.
Changes in the Fine Structure of Rubber Vulcanizates Fatigued by Repeated Force
Authors: Udagawa Y. 
Published: February 2011

Abstract
A novel method to detect the orientation of SBR molecules in SBR vulcanizates has been developed. It has been found that the swelling agent, benzene, crystallizes in SBR vulcanizates (oriented crystallization), reflecting the orientation of SBR molecules. This method is named the “Benzene Crystallization Method”.
Determination of Sequence Distribution of Styrene Units in Cured SBR
Authors: Tanaka Yasuyuki , Nunogaki Kazuki , Adachi Junichi 
Published: February 2011

Abstract
The sequence distribution of styrene units in cured SBR was analyzed by high-resolution GPC measurement on the ozonolysis products obtained by ozonization of finely powdered samples suspended in methylene chloride followed by reductive degradation with lithium aluminum hydride. The conversion of the ozonolysis products, which were soluble in the organic layer, approximated that of an uncured sample when 100% of the calculated amount of the ozone required to react with the double bonds in the butadiene units was used. The conversion decreased slightly as the amount of ozone was increased to 220%. The fraction of monad, diad, and triad styrene sequences which were flanked by 1,4-butadiene units, and styrene long sequences—observed at the GPC exclusion limit of 3×103—leveled off at about 100 to 150% of the required ozone. In the GPC fraction corresponding to long styrene sequences, the residual butadiene units, as measured by 1H-NMR, decreased from 77 to 47% as the ozone increased from 3.7 to 80% of the required amount. Ozonization was believed to proceed rapidly on the surface of the swollen rubber particles in the initial stage, and then it progressed gradually into the inner part upon introducing excess ozone. Cured SBR samples, with and without carbon filler, showed sequence distributions of the styrene units which were similar to the uncured sample when 130% of ozone was used.
From Vulcanization Model to Process Control
Authors: Veltman B. , Van Hastenberg C. 
Published: February 2011

Abstract
A simulation model has been presented, which is able to predict, quantitatively, the degree of cure, if temperatures in the product rise above a start temperature of the vulcanization reaction and if a correct initial temperature is used as input. The importance of controlled injection temperature and monitored cavity pressure for process reproducibility have been elucidated. The Cure Command was tested and was found to be useful within limits. A superior process control has been suggested, which could be realized nowadays using microcomputer technology.
Sulfur Vulcanization with Two Plateaus—Formation of an Inhibitor during Vulcanization?
Authors: Loo C. T. , Porter M. , Tidd B. K. 
Published: February 2011

Abstract
Efficient sulfur vulcanizing systems based on thiazolesulfenamide accelerators derived from secondary amines show unusual and complex vulcanization kinetics in NR. This feature does not appear to have been reported previously. Depending on the nature and purity of the accelerator, the ratio of accelerator to sulfur, the cure temperature, the type of rubber being used, and the presence of other additives, two distinct periods of crosslinking may be evident, separated by a more or less well-defined plateau. This plateau is longer and more distinct if the accelerator is pure, its ratio to sulfur is high, the cure temperature is low, and there are no other additives present. Sulfenamide accelerators derived from both primary and secondary amines may give rise to this behavior in rubbers other than NR. The observed behavior has been shown to be due to the formation, during the first cure period, of an extractable crosslinking inhibitor. The structure of this inhibitor is still in doubt, but the present balance of evidence favors it being an aminodithiobenzothiazole [Structure (1)] or a dithiobisdialkylamine [Structure (2)] or a polythio variant of those structures.
Blends of Dissimilar Rubbers—Cure-Rate Incompatibility
Authors: Coran A. Y. 
Published: February 2011

Abstract
The mechanical properties of a vulcanizate of a blend which comprises both a high-diene rubber such as NR and an ozone-resisting concentration (at least 30 to 40 wt.% of the polymers) of EPDM can be greatly improved if the EPDM is chemically modified by the action of maleic anhydride. The effect of the EPDM modification of the vulcanizate properties is to give increased tensile strength, improved fatigue resistance, and reduced hysteresis and set. The excellent ozone resistance which results from the presence of about 30 to 40% unmodified EPDM is also obtained when the modified EPDM is used. Good results are obtained when only 1 to 2% (as a wt.% of EPDM) of maleic anhydride is used in the modification of the EPDM. Good results are obtained when only part of the EPDM is modified by the action of maleic anhydride. However, best results are obtained when all of the EPDM is treated with maleic anhydride. The ozone-resisting effect provided by the incorporation of a para-phenylenediamine antidegradant into a 60/40 NR/EPDM blend vulcanizate is overwhelmed and made obscure by the very large beneficial effect due to the presence of the EPDM. However, the use of an antidegradant such as 6PPD is still necessary because of its ability to impart a great improvement in fatigue life.
A Rheo-Optical Study of the Influence of Additives on Crystallization Rates in Cis-1,4 Polyisoprene
Authors: Chen Yun-Jin , White James L. , Min Kyonsuku , Nakajima Nobuyuki , Weissert Frederick C. 
Published: February 2011

Abstract
A rheo-optical study of the influence of additives on crystallization rates in synthetic cis-1,4 polyisoprene (IR2200) at room temperature is presented. Nine different additives at a 1% concentration were examined. This study has found many additives which seem to be effective in enhancing the rate of stress-induced crystallization in IR2200. We have found that there is a good relation between enhancement of green strength and fraction of stress-induced crystallinity, ϕc, in IR2200 caused by additives.
Statistical Methods in Rubber Research and Development
Authors: Derringer George C. 
Published: February 2011

Abstract
As this article has demonstrated, statistical methods have considerable utility in rubber research and development. Such methods are cost effective and perhaps, more important, help the user to formulate questions in such a way as to make research programs more productive. The use of statistical methods in formulation development have been particularly fruitful. For example, without statistical methods, the compounders common task of simultaneously achieving a specific balance of cost, property levels, and processing behavior would be an expensive undertaking at best and hopeless at worst. Statistical methods help the practitioner make sound decisions in the light of often extreme variability in the data. This is especially the case when the data is fatigue, tensile strength, or some other fracture property of rubber. In the light of such broad distributions, hit or miss and one variable at a time strategies are seriously flawed. It is not hard to find a sequential study in which decisions about each trial were driven simply by changes due to random variability which were erroneously attributed to the intentional changes in variable level(s) from the previous trial. Such research studies are very similar to random walks. Many excellent and innovative studies are reported above. However, given the wide utility of statistical methods, these methods appear to be underutilized judging from the unexpectedly small number of papers which were found. Similarly, it is not difficult to find published rubber research which would not have benefitted by the use of statistical experimental design and/or data analysis. Fortunately, however, this appears to be changing. The increasing availability of good affordable software for personal computers makes it possible for good statistics to be done with less dependence on trained statisticians which are not available in many organizations. As this trend continues, the number of studies employing statistical methods will surely grow.
Silicone Rubber, Its Development and Technological Progress
Authors: Polmanteer Keith E. 
Published: February 2011

Abstract
This paper has described silicone rubber, its first commercial development in 1944, and its technological progress since then. Pioneering research on silicon opened the door to the development of silicone polymers and silicone rubber. The substitution of two methyl groups on silicon was present in the first examples of silicone rubber and still is the predominant organic group in commercial silicone rubber today. Silicone rubbers have filled a need in the marketplace because of their combination of unusual properties not found in other rubbers. The alternating inorganic main-chain atoms of silicon and oxygen, and the two pendant organic groups, primarily methyl, provide strong chain bonds, backbone flexibility, ease of side-group rotation, and low “inter” and “intra” molecular forces. This molecular makeup and properties thereof are primarily responsible for the observed performance of silicone rubbers. Many significant advances in silicone rubber have been discussed in chronological sequence to trace its history from 1944 to 1987.