bluuebunny/crossref_metadata_2025_split huggingface dataset:
Influence of Powder Surface Treatment on the Dispersion Behavior of Silica into Polymeric Materials
Authors: Scurati Alberto , Manas-Zloczower Ica , Feke Donald L. 
Published: February 2011

Abstract
The effect of surface treatment on silica agglomerate dispersibility was investigated. Precipitated silica powders were treated with a commercially available coupling agent Bis-(triethoxysilylpropyl)-tetrasulphane (TESPT) in a blender. Spherical agglomerates of known density were prepared and dispersed in styrene butadiene rubber (SBR) under controlled flow conditions. The erosion kinetics was monitored by measuring the reduction in size of parent agglomerate with time. Silica dispersibility was greatly enhanced upon surface treatment. The coupling agent used in surface treatment is known to reduce filler—filler interactions and therefore affects the intrinsic cohesivity of the powder. However powder surface treatment can also induce changes in agglomerate morphology and filler-liquid interactions. The work presented in this paper evidences such changes.
The Variation with Temperature of the Dynamic Properties of Rubber and Synthetic Rubberlike Materials
Authors: Fletcher W. P. , Schofield J. R. 
Published: February 2011

Abstract
(1) Over the range from 5° to 40° C, the temperature coefficients of the dynamic compression moduli of all the rubber and rubberlike materials studied are negative and fall numerically with increasing temperature. (2) The highest numerical value of this coefficient for natural rubber is −2.7×10−3 per ° C. Neoprene-Gn has a coefficient 3 to 4 times this value and Buna-S about 5 times. Hycar OR-15 shows the highest coefficient of −1.3×10−1 per ° C from 10 to 20° C, the value changing sharply at 20.2° C to −0.14×10−1, which is maintained up to 40° C. (3) Results for Neoprene-E were not reproducible, owing to a type of slow freezing effect. (4) In all cases but Thiokol-RD resilience tended to increase with increasing temperature throughout the range. (5) Resilience-temperature curves for natural rubber, Neoprene-GN, Neoprene-YD, and Buna-S take the form of straight lines intersecting at 20° to 22.5° C. Neoprene-Z shows a similar effect with intersection at 30.5° C. and Hycar OR-15 similarly at 31.5° C. (6) Copolymers of butadiene and acrylonitrile show increasing modulustemperature coefficient, and in the region 10° to 20° C decreasing resilience with increasing acrylonitrile content. The resilience-temperature diagrams for these polymers, except Hycar OR-15, are smooth curves which appear to reach steady values towards the upper end of the temperature range. (7) Thiokol-RD appears to have a freezing-point, under the dynamic conditions employed, somewhere in the region of 15–20° C; there is evidence that Hycar OR-15 shows a similar effect between 0° and 10° C. (8) The relationships enumerated above refer to basic compounds of the various materials. How far the temperature effects may be reduced or modified by suitable compounding is the subject of continuing investigation.
Swelling of Synthetic Rubbers in Mineral Oils. Effect of Temperature and Aniline Point
Authors: Powers P. O. , Billmeyer B. R. 
Published: February 2011

Abstract
The aniline point of hydrocarbon oils and solvents is a satisfactory index of the swelling of oil resistant synthetic rubber compositions. The logarithm of the percentage volume increase varies inversely with the aniline point up to 100 per cent swelling. The slope of the swelling curve is apparently characteristic of each synthetic rubber, and is not affected by loading, temperature or degree of cure. Slight swelling does not greatly decrease the tensile strength, but above 100 per cent swelling the strength is greatly reduced.
The Fatigue Life of Hevea and Guayule Rubbers
Authors: Santangelo P. G. , Roland C. M. 
Published: February 2011

Abstract
The enhanced crystallizability of guayule rubber (GR) in comparison to Hevea-based natural rubbers (NR) gives rise to better failure properties in unfilled, or “gum,” GR. The origin of this behavior is the ability of the non-polymeric contaminants in GR to nucleate strain crystallization; a similar effect is operative in less pure grades of NR. However, when compounded with carbon black, this superiority of GR over NR is lost. The mechanical hysteresis arising from the carbon black, along with the latter's enhancement of strain crystallization, supercede the contribution from the contaminants. Consequently, in contrast to the behavior of the gum rubbers, the fatigue lifetimes of GR- and NR-based compounds are equivalent.
A Review of Some of the Factors Affecting Fracture and Fatigue in SBR and BR Vulcanizates
Authors: Zhao J. , Ghebremeskel G. N. 
Published: February 2011

Abstract
This paper reviews the effects of polymer macrostructure (molecular weight and the styrene content of SBR) and diene microstructure on the fracture and fatigue life of styrene-butadiene rubber (SBR) and butadiene rubber (BR) vulcanizates. Effects of experimental parameters, such as carbon black and vulcanizing systems, on fracture and fatigue are also discussed. Investigations were performed under static (tensile and tear) and dynamic (fatigue) testing conditions. Finally, the underlying failure mechanisms are discussed.
Influence of Processing History and Composition on the Basic Structure and Biaxial Deformation Behavior in Dynamically Vulcanized PP/EPDM Blends
Authors: Wang M. D. , Cakmak M. 
Published: February 2011

Abstract
Thermal, crystallographic and mechanical properties of unvulcanized and dynamically vulcanized polypropylene/ethylene—propylene—diene monomer rubber (PP/EPDM) thermoplastic elastomer blends were investigated. In these high PP content blends, PP forms the continuous phase. The crystalline regions of the PP is mostly in alpha crystalline form with a small fraction of beta. The additives were found to suppress the beta fraction formation. The results indicate that the PP phase maintains its integrity up to the blend concentrations containing 20% EPDM. Beyond this concentration, the unit cell structure was found to become enlarged in its basal plane. This is also manifested in other properties as the melting point began a significant decrease at this concentration level. Interestingly, the film processability greatly improved beyond this 80/20 concentration and the temperature range, over which uniform films were obtained, was significantly enlarged as a result of reduction of neck formation. This was attributed to the formation and homogeneous distribution of large numbers of micronecks in the PP phase, nucleated by the presence of rubber regions.
New Thermoplastic Elastomers from Poly(Ethylene-Octene) (Engage), Poly(Ethylene-Vinyl Acetate) and Low-Density Polyethylene by Electron Beam Technology: Structural Characterization and Mechanical Properties
Authors: Chattopadhyay S. , Chaki T. K. , Bhowmick Anil K. 
Published: February 2011

Abstract
New thermoplastic elastomers have been prepared from the blends of metallocene-based polyolefins (Engage) with low-density polyethylene (LDPE), and ethylene-vinyl acetate copolymers (EVA) of different grades with LDPE by electron beam modification. Structural changes of these blends with or without sensitizer in presence of irradiation have been evaluated by X-ray diffraction (XRD) and differential scanning calorimetry (DSC). Scanning electron microscopy (SEM) in conjunction with atomic force microscopy (AFM) indicate the soft rubber domain in the continuous plastic matrix. Significant improvements of mechanical, dynamic mechanical and set properties have been obtained by electron beam modification, retaining its reprocessibility characteristics. Effects of ditrimethylol propane tetraacrylate (DTMPTA) as radiation sensitizer have also been evaluated from the mechanical, dynamic mechanical properties and reprocessibility.
Hysteretic Energy Loss in Cord/Rubber Composites under 2-D Cyclic Loading
Authors: Gurvich Mark R. , Andonian Archie T. , Kim Soojaa L. 
Published: February 2011

Abstract
Cord/rubber composites are often considered as homogeneous anisotropic media in macro-mechanical structural analysis. Challenges, however, are associated with significant non-linearity of their deformation and the visco-elastic nature of rubber matrix. These visco-elastic composites are often subjected to cyclic loading conditions (periodic excitations) and exhibit energy losses due to their hysteretic behavior. An approach is proposed to quantify these hysteretic energy losses under general case of two or three-dimensional cyclic loading. The approach provides a simple mathematical description of this non-linear visco-elastic phenomenon. Representative experimental data are considered to show the reliability of the approach. Uni-directionally reinforced single layer composites are considered under different off-axial cyclic loads to model 2-D stress/strain states. Possible methods are discussed to define composite properties using the proposed approach.
Rubber Chemicals Derived from Conjugate Addition. II. Synthesis of a Novel Class of Benzoquinone Diimines
Authors: Katritzky Alan R. , Odens Herman H. , Voronkov Michael V. , Rostek Charles J. , Maender Otto W. 
Published: February 2011

Abstract
Various 2-alkylthio-5-amino- and 2,5-diamino-1,4-phenylenediamines were prepared by treatment of N-(1,3-dimethylbutyl)- N′-phenyl-1,4-quinonediimine with thiols and amines using air as an oxidizing agent. Key 2-alkylthio-1, 4-benzoquinone diimines were prepared via Ag2O oxidation of the corresponding 1,4-phenylenediamines.
Evaluation of Crosslinking in Elastomers Using Thermoporometry, Densimetry and Diffential Scanning Calorimetry Analysis
Authors: Baba Mohamed , George Soney C. , Gardette Jean Luc , Lacoste Jacques 
Published: February 2011

Abstract
The classical methods available for evaluating the degree of crosslinking in elastomers are stress-strain and swelling measurements. In this study, we have adopted a new analytical approach based on thermoporometry, densimetry and DSC for comparing the crosslinking density in elastomers. Crosslinking by chemical reaction or by photo-oxidation has been studied on polymer samples Ethylene-Propylene-Diene rubber (EPDM) and PolyButadiene (PB). Analysis has been done separately for soluble and insoluble fractions. The soluble fraction has been studied by densimetry and the insoluble fraction by thermoporometry and measurement of decomposition of dicumyl peroxide (DCP). The results of both these studies are complementary to each other. The DSC thermal curves of both EPDM and PB are identical in nature, but the density of the photo-oxidized EPDM samples shows a marked increase contrary to that found in PB.
Evaluation of Natural Rubber from Clones of Hevea Brasiliensis
Authors: Ferreira Mariselma , Moreno Rogério M. B. , Gonçalves Paulo S. , Mattoso Luiz H. C. 
Published: February 2011

Abstract
The latex and natural rubber from rubber trees [Hevea brasiliensis (Willd. exAdr. de Juss.) Muell. Arg.] from clones (RRIM 600, IAN 873, GT 1 and PB 252) recommended to the state of São Paulo, Brazil, were studied in three different tapping systems. The parameters studied were dry rubber content (DRC), percentages of ash and of nitrogen, Wallace Plasticity (P0) and Mooney Viscosity (VR). The rubber properties vary considerably as a function of clone type, tapping method and season of the year. DRC tends to decrease in the beginning of the dry, cold season (May and June), whereas both nitrogen % and ash % increase in the same period. A good linear correlation was obtained for P0 and VR. The highest P0 and VR were obtained for RRIM 600.
Solid State 13C NMR Applied to Styrene-Butadiene Rubbers Study of the Rubber Vulcanized Network Structures
Authors: Pellicioli L. , Mowdood S. K. , Negroni F. , Parker D. D. , Koenig J. L. 
Published: February 2011

Abstract
This paper discusses the structural changes that occur during the accelerated sulfur vulcanization of styrene-butadiene rubbers (SBR) through characterization of the network sulfide structures influenced by the curing agent concentration, the polymer microstructure, and the nature of the filler. Magic angle spinning (MAS) 13C FT - NMR spectroscopy was used to investigate the chemical crosslink properties of unfilled vulcanized SBR in addition to carbon black and silica filled polybutadiene rubber (BR), SBR, and 1:1 BR / SBR blends. New resonances in the 13C NMR spectrum are assigned to the various sulfide crosslink structures in SBR. Structural changes during vulcanization are also discussed.
Fillers for Balancing Passenger Tire Tread Properties
Authors: Byers John T. 
Published: February 2011

Abstract
Strong demands for lower rolling resistance tires in Europe led to the introduction of a new filler system for auto tire treads in the early 1990s. Silica, in combination with a silane coupling agent, was used as the primary filler system despite the increased costs compared to carbon black. The adoption of silica/silane treads has been slower outside of Europe, but some conversion to silica/silane or alternative filler blends has taken place in North America and Japan. This paper is a review of the many reports related to the silica/silane filler system, as well as alternative approaches — including new carbon blacks — to lower rolling resistance, that have been generated since the introduction of the “green tire” concept in the early 1990s.
Surface Energy of Silica Xerogels and Fumed Silica by Inverse Gas Chromatography and Inverse Liquid Chromatography
Authors: Donnet J. B. , Li Y. J. , Wang T. K. , Balard H. , Burns G. T. 
Published: February 2011

Abstract
Inverse gas chromatography (IGC) and inverse liquid chromatography (ILC) have been used to detect the interaction energy between silicas (fumed silicas and silica xerogels) surfaces and probes molecules. The silica surfaces were modified chemically by trimethylsiloxane functions. Either IGC or ILC have detected the adsorption energy change following the surface modification. In IGC technique, the results with several probes show clearly the physico-chemical properties of the silica surfaces. ILC was developed to use bigger probe molecules which are more similar in structure to polymers. In this work, squalene, a non volatile molecule with 30 carbon atoms and several double bonds, was used in ILC to simulate elastomer molecules.
Mechanisms of Adhesion in Surface Chlorinated Thermoplastic Rubber/Thermoplastic Polyurethane Adhesive Joints
Authors: Pastor-Blas M. Mercedes , Martín-Martínez José Miguel , Boerio F. J. 
Published: February 2011

Abstract
Chlorination of a thermoplastic styrene-butadiene-styrene rubber (S0) with a solution of 2 wt% trichloroisocyanuric acid (TCI) in ethyl acetate improved its adhesion to polyurethane adhesives. The analysis of the failed surfaces (obtained after T-peel test of S0/PU joints) showed that the locus of failure in the rubber/polyurethane joints progresses from adhesion (in non chlorinated-S0/PU joint) to cohesion in the chlorinated layer (for chlorinated-S0/PU joint). The composition of this chlorinated layer differed from the composition of the non bonded-chlorinated rubber, i.e. the failure of the joint was located in a chlorinated layer with a distinctive chemistry. On the other hand, the analysis of the chlorinated rubber/PU adhesive interface showed that chlorination with TCI produces a crosslinking of the rubber surface as well as strong interactions between the uppermost-chlorinated layer and the PU adhesive.
Quality and Performance of Carbon Blacks from Plasma Process
Authors: Probst N. , Grivei E. , Fabry F. , Fulchéri L. , Flamant G. , Bourrat X. , Schröder A. 
Published: February 2011

Abstract
Plasma carbon black, a new material? For several years already, the Plasma process for carbon black production has been promoted and considered as a threat to the furnace black production.
After a brief introduction to the fundamental differences between a partial combustion process and plasma process, plasma blacks have been compared with partial combustion blacks. The plasma blacks have not been optimised but are more a selection of materials based on feedstock and operating conditions. Physico-chemical properties as well as SEM and high resolution TEM micrographs illustrate differences and similarities. Surface heterogeneity of those carbon blacks has been characterised by static gas adsorption. This way the more graphitic nature of the selection of plasma blacks could be demonstrated, explaining the specific behaviour of those blacks in rubber compounds.
The specificity of the carbon blacks investigated is not only in the production technique, namely plasma torch, but also in the variety of the row materials used, demonstrating the flexibility of the process. Methane, ethylene, pyrolysis fuel oil and even a renewable vegetable oil have been used.
Effect of Crosslink Density on Cut Growth in Black-Filled Natural Rubber Vulcanizates
Authors: Hamed G. R. , Rattanasom N. 
Published: February 2011

Abstract
Tensile strengths, σb, of gum and N115-filled natural rubber test pieces, with and without edge pre-cuts, have been determined. At low crosslink density, the regular (uncut) σb of filled and gum vulcanizates is similar. However, at high crosslink density, the gum NR becomes brittle, while the corresponding filled rubber remains strong and resistant to cut growth. It is proposed that the tightly linked gum does not strain-crystallize appreciably during stretching, but that its filled counterpart does. Carbon black appears capable of inducing crystallization in a network that alone remains amorphous during extension.
Filled vulcanizates of various crosslink densities have similar normal tensile strengths ( ≈ 30 MPa), but strengths differ, sometimes more than twofold, if a pre-cut is present. Lightly crosslinked specimens containing a small cut have strengths that depend very weakly on cut size, c. Furthermore, these develop long longitudinal cracks from which catastrophic rupture initiates. With larger cuts, strength decreases more rapidly with increasing c, there is less longitudinal crack growth, and rupture initiates near the original cut tip. In contrast, the strength of a highly crosslinked vulcanizate is sensitive to small cuts and test pieces exhibit minimal longitudinal cracking before failure.
The Influence of Silane Sulfur and Carbon Rank on Processing of a Silica Reinforced Tire Tread Compound
Authors: ten Brinke J. W. , van Swaaij P. J. , Reuvekamp L. A. E. M. , Noordermeer J. W. M. 
Published: February 2011

Abstract
The effect of the sulfur rank (4-0) and of the carbon rank (2-10) of equivalents of bis(triethoxysilylpropyl)tetrasulphide TESPT as coupling agents for silica-reinforced tire tread compounds, is the subject of this study. The coupling agents are added in quantities equimolar to TESPT. Sulfur correction for lower sulfur ranks than TESPT is performed either in the final mixing step or in the first mixing step in an internal mixer.
Without sulfur correction the silanes studied show a marked difference in processing as well as in the final properties of the rubber. When sulfur correction is made in the final mix together with the addition of vulcanization ingredients, all sulfur-containing silanes behave more like TESPT. The disulphide (TESPD) shows final properties similar to those of TESPT; the mixing behavior shows improved scorch safety. This is lost when sulfur correction is applied in the first mix.
Sulfur-free silanes do not react on sulfur correction during processing and show only a slight improvement in mechanical properties. A silane without sulfur, having a carbon rank of 10 (DTES) shows the best processing, although final mechanical properties are inferior to TESPT.
Superior Mechanical Properties of Ultrasonically Recycled EPDM Rubber
Authors: Yun Jushik , Isayev A. I. 
Published: February 2011

Abstract
This paper describes the results of an extensive study involving the continuous ultrasonic devulcanization of unfilled EPDM rubber. Die pressure and ultrasound power consumption were measured as a function of processing conditions. The mechanical properties of aged and fresh revulcanized EPDM rubber were measured. Gel fraction, crosslink density, and dynamic properties were also determined for the virgin vulcanizate, the ultrasonically devulcanized rubber, and the revulcanized rubber. Additionally, the cure behavior of virgin and devulcanized EPDM rubber was investigated. The tensile strength of revulcanized EPDM rubber was found to be much higher than that of the virgin vulcanizate with the elongation at break being practically intact. A mechanism explaining the increase in mechanical properties of revulcanized rubbers was proposed.
Adhesion Failure in Bonded Rubber Cylinders Part 2: Fatigue Life Prediction of External Ring-Shaped Cracks Using Tearing Energy Approach
Authors: Leicht Douglas C. , Rimnac C. , Mullen R. 
Published: February 2011

Abstract
Rubber disks bonded between flat parallel metal plates are often used as adhesion test specimens; for example, ASTM D 429 1999, Method A. However, the mechanics of adhesion failure (debonding) for this geometry have not previously been fully analyzed. Therefore, a study was conducted to determine the strain energy release rate (tearing energy) for bonded rubber disks having external ring cracks at the rubber-to-metal bond and to develop a method for predicting the fatigue life.
Finite element analysis was used to determine the tearing energy as a function of crack length for disks of various dimensions (shape factors). The crack configurations considered were an external-ring-shaped crack located at the outside circumference of either one or both rubber-to-metal bonds. The fatigue crack propagation (FCP) behavior was characterized for a generic filled natural rubber material.
The tearing energy was found to be a non-linear function of crack length. For small cracks, the tearing energy was small and approached zero as the crack length decreased. The tearing energy then increased as the crack grew, indicating accelerating growth, until it passed through a maximum value. The peak tearing energy was found to depend on the height of the disk. Finally at large cracks, the tearing energy decreased or was essentially constant as the crack grew.
The fatigue life of the rubber cylinders at different shape factors was determined experimentally. An empirical model coupled with the fatigue crack propagation behavior (FCP) for the material at different tearing energies was used to predict the fatigue life. The experimental and predicted fatigue life showed excellent agreement at low and moderate shape factors. However at high shape factors, fatigue life was not well predicted. From the experimental results, it was found that, at high shape factors, cavitation occurs causing a series of “dimples” to form, which leads to the development of an internal penny-crack, thereby violating the assumed model of an external ring-shaped crack.