bluuebunny/crossref_metadata_2025_split huggingface dataset:
Processing Ease and Rubber—Carbon-Black Interaction
Authors: Nakajima N. , Miller R. A. 
Published: February 2011

Abstract
Two samples of poly(ethyl acrylate) rubber, different in their mill processability and their manner of accepting carbon black were examined. This is a case history of how we differentiated Theological behavior of gum elastomers and how we characterized the rubber—carbon-black interaction in the compound. For the former objective, the dynamic mechanical properties were measured over the temperature range of interest. This information was used to interpret the difference in mill processability. For the latter objective, several carbon blacks in different particle size and structure were compounded with these samples. The effect of the different carbon blacks on these elastomers was examined with tensile stress-strain measurements. At least a part of the differences in behavior could be interpreted as the differences in the interaction between rubber and carbon black.
Effect of Carbon Black on the Mechanical Properties of Elastomers
Authors: Meinecke Eberhard A. , Taftaf Mansour I. 
Published: February 2011

Abstract
The strain-amplification concept developed by Guth and Gold can predict the effect of carbon black loading on the mechanical properties of elastomers, provided that the experimental conditions and the samples correspond to the assumptions made in the derivation of the Guth-Gold equation, namely: a) Any artifacts arising from dynamic testing in tension have to be considered and eliminated by the proper analysis. b) Samples have to be prestretched prior to testing to break up particle agglomerations and to eliminate any possible entanglement slippage. c) Spherical particles have to be used or Medalia's occluded volume concept has to be applied for fillers with high structure. d) Hysteresis properties are dependent upon the square of the strain-amplification factor. e) Viscoelastic effects on the shape and level of stress-strain curves have to be eliminated.
Autohesion and Cohesion of Uncrosslinked Elastomers
Authors: Hamed Gary R. 
Published: February 2011

Abstract
Over the past several years the author and collaborators have studied the autohesion (tack) and cohesion (green strength) of uncrosslinked elastomers. It is the purpose of this short review to present some highlights of this research. This is not meant to be a brief review of the entire literature on the subject.
Elastomers—Past, Present, and Future
Authors: Mark Herman F. 
Published: February 2011

Abstract
If we look back on our story we might summarize: laborious and imaginative pioneering was done over about 100 years in the past. As soon as a few basic principles were established, the synthesis, structure, and uses of elastomers rapidly invaded large disciplines of polymer science and engineering in 60 years up to the present. From now on, in the future, there can be expected a period of more concentrated efforts on selected problems of special urgency.
Ambient Electrical Properties of Mica-Styrene-Butadiene Rubber Composites
Authors: Debnath S. , De Prajna P. , Khastgir D. 
Published: February 2011

Abstract
We have studied the effect of addition of (a) mica, (b) silane coupling agent, and (c) silane-treated mica on the ambient dielectric properties of vulcanized styrene-butadiene rubber. It is observed that both dielectric constant and dielectric loss increase as mica, silane, and silane-treated mica are added. The increase is more pronounced in the case of silane-treated mica than for the untreated mica systems. The observed values of dielectric constants are in close agreement with the calculated ones obtained from different theories of heterogeneous dielectrics. Dielectric strength shows an increasing trend in the presence of mica. At higher mica loading, D.C. conductivity decreases slightly.
Photocrosslinking of EPDM Elastomers. A New Method for Rapid Curing of Elastomer Coatings at Room Temperature
Authors: Hilborn J. , Rånby B. 
Published: February 2011

Abstract
Photocrosslinking with UV light in air of silica-filled EPDM rubbers is possible in practical applications for at least 2 mm thick layers which are cemented onto a steel substrate. To find the optimum formulation of the rubber composition, it is essential to know the function of each component. Further optimization can be achieved by using the APOE to the TMPTA system and by using a suitable primer cement on the metal.
Morphology and Physical Properties of Thin Films of Thermoplastic Elastomers from Blends of Natural Rubber and Polyethylene
Authors: Akhtar Sania 
Published: February 2011

Abstract
The morphology and properties of thin films prepared from NR-PE blends have been discussed. The present paper emphasizes the effect of method of preparation on the final properties. To this end, the films were quenched in ice (−10°C), cooled in water (25°C), cooled in air (30°C), and cooled in the press (from 160°C to room temperature) under a pressure of 0.34 MPa. The modulus, tensile and tear strengths, and elongation at break were found to vary considerably with the method of preparation. X-ray and DSC results confirmed the fact that the changes were related to the crystallite morphology rather than the degree of crystallinity. In addition, it was observed that the high rubber blends were less susceptible to the method of preparation than the high plastic blends and pure polyethylene.
Mixing of Carbon Black with Rubber. VI. Analysis of NR/SBR Blends
Authors: Cotten George R. , Murphy Lawrence J. 
Published: February 2011

Abstract
The distribution of carbon black in NR/SBR blends was determined through the analysis of bound rubber. The NR/SBR blends were found to be very different from the previously studied SBR/BR compounds: these differences were assigned to mutual insolubility of the two polymers and a very high molecular weight of NR. In NR/SBR blends, it was found that changes in molecular weight of the polymer has no effect on the carbon black distribution in the blend. While the “activity” of carbon black did not affect the distribution, the loading of the black in NR decreased linearly with increasing surface area of the black. Approximately 35% of normal tread blacks (surface area 80–100 m2/g) was found in the NR phase. However, the bond between NR and carbon black is quite weak, and black continues to migrate into the SBR phase on prolonged mixing or during blending of NR and SBR masterbatches.
Identification of Organic Components in Uncured Rubber Compounds Using Mass Spectrometry
Authors: Lattimer R. P. , Harris R. E. , Rhee C. K. , Schulten H-R. 
Published: February 2011

Abstract
Three carbon-black-filled rubber compounds of known composition were analyzed by mass spectrometry. Direct thermal desorption was used with three different methods of ionization (EI, CI, FI). In addition, the three rubbers were examined by FAB-MS (without liquid matrix) as a means for surface desorption/ionization. Extracts of the rubbers were also examined using two different solvents (acetone and acetonitrile). Each extract was examined directly by five methods of ionization (EI, CI, FI, FD, FAB). Of the various vaporization/ionization methods, it appears that FI/FD is the most efficient for identifying typical organic additives in rubber stocks. The analysis can be carried out using either the untreated rubber (FI mode) or else a solvent extract (FD mode). Molecular ions are dominant, which facilitates the characterization of the complex organic additive mixtures that are present in typical compounded rubbers. For samples in which the identity of FD/FI molecular ions is unclear, further analysis using other methods (EI, CI, FAB, MS/MS, GC/MS, LC/MS, high resolution) can be carried out to gain additional information. We conclude that FD and FI yield the most useful information in the shortest period of time. The main difference between the results of this study and those of the volcanizate study is with respect to the curatives. Intact accelerator molecules could readily be observed in the spectra from the uncured stocks, while only accelerator fragments could be observed from the vulcanizates.
An Experimental Study of Flow and Stress Fields in a Pressurized Mooney Viscometer
Authors: Montes Sergio , White James L. , Nakajima Nobuyuki , Weissert Frederick C. , Min Kyonsuku 
Published: February 2011

Abstract
The boundary conditions of rubber compounds on solid surfaces during extrusion has long been a subject of question. The concerns of Mooney on this topic date back 60 years. He continued to return to this question throughout his career. In more recent years Vinogradov and his coworkers have called attention to slip phenomena occurring in the extrusion of elastomers through dies. This is associated with fluctuating pressure losses which occur at the onset of extrudate distortion. Such behavior has also been observed with rubber-carbon-black compounds. More recently, Turner and Moore have developed a pressurized rotational rheometer to characterize this type of behavior in rubber compounds. We have recognized the importance of this problem in our own laboratories. Marker experiments have been used in extrusion of rubber compounds to detect slippage. In the present paper, we describe an experimental study of the response of gum elastomers and their carbon black compounds in a pressurized Mooney viscometer of the general design of Turner. We look first specifically at the variations of steady torque (shear stress) with the magnitude of applied pressure. We then look at the characteristics of sheared samples and the responses to pressure transients.
A Novel System for Crosslinking Fluoroelastomers
Authors: Ogunniyi D. S. 
Published: February 2011

Abstract
The use of HBTBP as a crosslinking agent in fluoroelastomers has been reported. HBTBP was found to be especially suitable for FKM-G polymer, and the mechanism of crosslink formation in this fluoroelastomer was investigated. Compounding studies, swelling measurements, solvent extraction, and nitrogen tests have been used to tentatively shed light on the crosslinking mechanism. The results of these tests were used to propose mechanisms of crosslink formation occurring through a combination of: (i) radical abstraction of the methylenic hydrogen in FKM-G and crosslink formation through the interaction of the resulting radicals, (ii) interaction of a reactive intermediate from (i) with the raw FKM-G polymer, and (iii) nucleophilic substitution.
Structure-Property Relationship in Rubber-Modified Propylene-Ethylene Block Copolymer Blends
Authors: Sain M. M. , Hudec I. , Beniska J. , Rosner P. 
Published: February 2011

Abstract
The incorporation of a phase modifier, as is well known in the case of elasto-plastic blends, leads to an improvement of mechanical properties and brittleness character for PRP-EVA blends. Similarly, the influence of a cocuring agent and a phase modifier on NR-PRP blends also improved the mechanical properties. Although the modification of the PRP-EVA blend has very little influence on glass transition temperatures, the NR-PRP blends show a measurable shift in their glass-transition temperatures. It is demonstrated that strong interaction occurs between the elastic and plastic components of the blends. Further, it has been shown that this interaction is responsible for improved properties of the blends over that of the pure polymer components.
Monte Carlo Simulation of Styrene-Butadiene Elastomers
Authors: Stamhuis J. E. , Heitman W. G. , van Ballegooijen H. , Osborne D. J. 
Published: February 2011

Abstract
A relatively simple model for SBR networks has been developed that is based on reaction kinetics. In addition, any copolymer structure not directly originating from reaction kinetics but from the polymer physicist's imagination can be fed into the model; the only thing to be done in this case is to construct an imaginary polymer composition curve as input for the model. The model then visualizes in a quantitative manner the resulting polymer chains and their structure in the network in terms of monomer sequence distribution, network segment distribution, and the distribution of the crosslinks over the individual chains. These features are essentially the basis of further work regarding the mechanical and viscoelastic properties and, ultimately, the road behavior of solution-SBR-based tread vulcanizates.
Heat Build-Up and Blowout of Rubber Blocks
Authors: Gent A. N. , Hindi M. 
Published: February 2011

Abstract
The phenomenon of explosive “blowout” of thick rubber blocks, under repeatedly applied, severe compressive loads, is due entirely to the development of high internal temperatures. If the compound is electrically conductive, the phenomenon can be duplicated in a microwave oven without imposing any mechanical loads. Blowout appears to consist of the expansion to burst of pressurized cavities within the rubber. Pressure appears to be generated internally by a volatile constituent or decomposition product of the rubber compound. Expansion is restrained by elastic stresses set up in the rubber as the cavity expands. Bursting is made easier in some compounds because they soften markedly at high temperatures and thus lose resistance to cavity expansion. Different elastomers have strikingly different blowout temperatures. Butyl rubber compounds blow out at relatively low temperatures, about 180°C, whereas NR and SBR compounds blow out at temperatures of about 200°C or higher. Also, different vulcanizate structures have different blowout temperatures. For example, materials with C-C or monosulfidic crosslinks show higher blowout temperatures than those with polysulfidic crosslinks. Polybutadiene compounds did not blow out at all. Instead, they developed internal cavities that grew in size and number but never burst open to the exterior, probably because the internal pressure never reached sufficiently high levels. It is concluded that the principal cause of blowout is the generation at high temperatures of sufficient quantities of a volatile decomposition product, but the reaction is specific to the particular elastomer and crosslinking system employed. It does not appear to consist of simple thermal decomposition of the hydrocarbon elastomer, which would require higher temperatures than those observed at blowout.
Strain-Rate Amplification of Carbon-Black-Filled Rubber Compounds
Authors: Nakajima Nobuyuki 
Published: February 2011

Abstract
The strain amplification is one of the recognized causes of the reinforcement of rubber by carbon black. Previously, we evaluated strain amplification in nonequilibrium, i.e., stress-strain measurements. Carbon-black-filled rubber compounds were used. In these examples, not only strain but also strain rate must be amplified, since it is a dynamic situation. Because the behavior of the gum matrix is strain-rate dependent, strain-rate amplification is also an important aspect of the rubber compound behavior. In this paper, we presented case studies of strain-rate amplification with several compounds involving variation of gum rubbers and carbon blacks.
Rubber-Bound Antioxidants. I. Amine Antioxidants Bound to Polychloroprene Rubber
Authors: Al-Mehdawe Mohammed S. , Stuckey J. E. 
Published: February 2011

Abstract
Amine antioxidants are found to react with chloroprene (CR) type-W rubber with its reactive chlorine atoms. These reactions take place during high-shear mixing in a torque rheometer, or in a Winkworth mixer at higher temperature, or during the vulcanization of the elastomers at 160°C. Mixed alkyl, aryl secondary amines are shown to react only at the alkyl-substituted amino group. The concentrations of the bound antioxidants are estimated by IR spectroscopy after complete extraction. Monsanto Rheometer studies show that, in many cases, the crosslinking reaction of CR rubber, which takes place through the chlorine atom, is reduced by the presence of the antioxidants. The effectiveness of the rubber-bound antioxidant is assessed by accelerated oven aging and stress techniques. It is shown that immobilization of amine antioxidants by combining them with the network does not impair their antioxidant activity.
Zinc Oxide Crosslinking Reaction of Polychloroprene Rubber
Authors: Miyata Yoshiaki , Atsumi Masao 
Published: February 2011

Abstract
There was some ambiguity on the reality of the formation of ether crosslinks in the ZnO crosslinking of CR. This report clearly indicates the absence of the ether crosslinks. The main reaction pathway of the ZnO crosslinking of CR is the addition of the carbonium ion formed from the isomerized 1,2 unit to the double bond in the neighboring 1,4 unit, catalyzed by ZnCl2. The isomerized 1,2 unit is formed by the rearrangement of allylic chlorine in the 1,2 unit. The crosslinking reaction takes place between one curing site and one main chain component, not between two curing sites. The intramolecular cyclization predominantly occurs as compared with the intermolecular reaction (crosslinking) in Scheme 2. Therefore, the efficiency of the ZnO crosslinking of CR is quite small as expected from the concentration of the curing sites (1,2 units). Model polymer of low molecular weight and NMR spectroscopy have led to a better understanding of the chemistry of this process.
The Resistance of Rubber Compounds to Brittle Crack Propagation
Authors: Aglan H. , Moet A. 
Published: February 2011

Abstract
1. A theory based on irreversible thermodynamics and minimal entropy production principles is presented. This constitutive model introduces a methodology to describe fatigue-crack propagation behavior in natural rubber vulcanizate over the entire range of the elastic-energy release rate. 2. The utility of this model has been proved and demonstrated in view of the establishment of the damage evolution coefficient μ and the energy barrier μTc−T for one rubber compound. 3. The theory calls for quantitative measurements of the amount of damage associated with crack advance in order to extract the specific enthalpy of damage, γ*. This true material parameter, γ*, which characterizes its resistance to crack propagation (fracture toughness) can be related to the microstructure of the material. Thus a useful microstructure-fracture-toughness relationship based on the present theory can be constructed. Such a relationship can guide the development of rubber compounds with superior fracture toughness.
Fixing between Metals and NBR Vulcanizates and Its Prevention
Authors: Mori Kunio , Watanabe Akira , Saito Minoru 
Published: February 2011

Abstract
When metals and NBR vulcanizates are put into contact an adhesive force is generated between them. The phenomenon is called fixing, and the adhesive force generated is defined as the fixing strength. The fixing strength is divided into an initial fixing at 30 min after loading and an after-fixing which thereafter occurs successively. The former fixing strength is exhibited by the physical adsorption forces of the NBR segments to the metal surfaces. The latter are based on the formation of first-order bonds which are brought about by the chemical reactions between the metals and NBR vulcanizates. These fixing strengths were influenced by the environmental factors such as testing time, temperature, and humidity; by the surface factors such as the surface roughness of the metals and NBR vulcanizates, the hardness of the NBR vulcanizates, and the surface conditions; and by material factors such as the kinds of metals and rubbers, the fillers, and other ingredients in vulcanizates. From the above results, the fixing phenomenon is explained as follows. At first, the segment molecules of the NBR vulcanizates diffuse to the metal surfaces and then the nitrile groups in the NBR vulcanizates are adsorbed on the surfaces of the metals. At this time, secondary-order bond forces are generated between the two materials. Succeedingly, the chemical reactions occur at the contact parts between the two materials and then are combined by first-order bonds. As a result, a high fixing strength, as cohesive failure, is generated. The fixing mechanism leads to the four indicators of fixing prevention: (1) the control of the contact areas, (2) the suppression of molecular motion of the NBR segments, (3) the inhibition of interfacial reactions, and (4) the introduction of inactive crosslinks and side chains. In this paper, the surface curing of the NBR vulcanizates, which leads to the suppression of molecular motion of NBR segments, and the blooming method which leads to the inhibition of interfacial reactions, were investigated. The former method is not always effective for preventing the fixing because it is difficult to produce the NBR vulcanizates with less fixing properties under ordinary industrial conditions. However, stearamide and methylene bis-erucamide are very effective blooming agents to prevent fixing, because they provide barrier films onto the surfaces of NBR vulcanizates.
Dependence of Wet Skid Resistance upon the Entanglement Density and Chain Mobility according to the Rouse Theory of Viscoelasticity
Authors: Rahalkar R. R. 
Published: February 2011

Abstract
Starting with the Rouse theory of viscoelasticity, the Theological behavior can be modeled in the transition zone. The predictions of the model are in qualitative agreement with both the experimentally obtained data in the transition zone and with the wet skid behavior of elastomers. Based upon the linear viscoelastic spectrum for amorphous polymers, the wet skid resistance of elastomers can be related to the chain flexibility. The Rouse mechanism is able to explain the wet skid results qualitatively for most of the commonly used elastomers, including IIR. This study establishes that transition region motions are influential in determining the wet skid behavior of an elastomer, with the glass transition temperature itself perhaps playing a minor role.
Observations Made During Stretching, Tearing, and Failure of NR and SBR Loaded with Various Amounts of Carbon Black
Authors: Goldberg Alfred , Lesuer Donald R. , Patt Jacob 
Published: February 2011

Abstract
Using a 35-mm camera with macro attachments, and focused on the tip of a cut, the stretching, tearing, and failure of notched samples of NR and SBR were documented during continuous testing. The propagation of a cut occurs by the stretching, tearing, and collapsing of fine strands, which we propose consists of bundles of long unwinding molecular chains of the rubber. Two main cut-growth regions are identified: a slow-cut-growth region consisting of irregular-shaped nodules or cells of collapsed rubber strands along short tear paths and a fast-cut-growth region consisting of long intersecting tear or cleavage paths leading to catastrophic failure. Addition of 20.6 phr (15 wt.%) carbon black results in a coarsening of the stretching, tearing, and fracture morphologies relative to those seen with the gum rubbers. Addition of 64 phr (35 wt.%) of carbon black results in all these structures being very fine with the phenomenon of knotty, deviated tearing dominating in the slow-cut-growth region. The knotty tearing is frequently revealed by the presence of chevron-like markings which correspond to the intersection of individual disoriented (deviated) tears. The initiation of tearing occurs at relatively low strains for all three carbon black loadings (0, 15, 35 wt.%); however, the strain to initiate tearing relative to the fracture strain was seen to decrease with an increase in carbon black, especially with the SBR series. Both failure strength and elongation increase significantly with carbon-black additions to SBR up to about 39 phr (25 wt.% of carbon black). With further additions, the elongation falls off, although the engineering strength remains unchanged, while the stiffness and tearing energies increase. With reference to the literature, we discuss the role of carbon black and deviated tearing on strengthening rubbers; suggestions are made for further research in this area.