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Tear Strength (tear + strength)
Selected AbstractsAcrylonitrile,butadiene rubber/reclaimed rubber,nylon fiber compositeADVANCES IN POLYMER TECHNOLOGY, Issue 4 2001T. D. Sreeja The effect of diphenylmethane diisocyanate (MDI),polyethyleneglycol (PEG) resin on the cure characteristics and mechanical properties of nitrile rubber/whole tyre reclaim,short nylon fiber composite,was studied. At a constant loading of 5 phr, the resin composition was varied. The minimum torque and (maximum , minimum) torque increased with isocyanate concentration. Scorch time and cure time showed a reduction on introduction of bonding agent. Properties like tensile strength, tear strength, and abrasion resistance increased with increase in MDI/PEG ratio, and these properties are higher in the longitudinal direction of fiber orientation. Compression set increased with isocyanate concentration and the resilience remain unchanged. © 2001 John Wiley & Sons, Inc. Adv Polym Techn 20: 281,288, 2001 [source] Processing and mechanical behavior of carbon black graded rubber compoundsJOURNAL OF APPLIED POLYMER SCIENCE, Issue 6 2010Sandeep S. Ahankari Abstract Functionally graded rubber compounds (FGRCs) were prepared by construction based method. The matrix used was natural rubber (NR). Amorphous carbon black (N-330) was used as grading material. The gradation of nanoparticles in a rectangular geometry comprised the variation of particle volume fraction along thickness direction. Its performance was evaluated for structural application through various mechanical and surface properties like tensile strength, modulus, tear strength, elongation at break, hardness, fracture surface by scanning electron microscopy, etc. At the same percentage of nanofiller loading, FGRCs show enhanced properties, i.e., modulus and tear strength (in some grades) compared to uniformly dispersed rubber compounds (UDRCs). Modulus of FGRCs, for a given particular stacking sequence of the layers, increases as much as by 275% compared to UDRCs. The ultimate properties like tensile strength and elongation at break made up for the modulus enhancement that decreases to as minimum as 50 and 80%, respectively. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010 [source] Effect of UV and hygrothermal aging on the mechanical performance of polyurethane elastomersJOURNAL OF APPLIED POLYMER SCIENCE, Issue 1 2008H. Aglan Abstract In this study, the effects of environmental aging on the mechanical performance of elastomeric polyurethane (PU) were investigated using two accelerated aging techniques, namely, ultraviolet (UV) and hygrothermal (HT). Samples were prepared and subjected to UV and HT exposure for a period of 5 months and removed and mechanically tested at different time intervals. Differential scanning calorimetry (DSC) was performed. A noticeable change in the chemical structure of the PU after 1 month of UV exposure was found, however, that was not the case after 1 month of HT exposure. The stress and strain to failure, tearing energy, and storage modulus were evaluated at different intervals for both aging techniques. It was found that the UV exposure caused severe degradation of the PU in comparison with the HT. A reduction of more than 98% in the tearing energy was observed for the UV-exposed samples after 5 months when compared with only a 35% reduction in the tearing energy for the HT-exposed samples. A similar trend was observed for tear strength and storage modulus. The degradation mechanisms of the PU elastomers have been identified using SEM and correlated with the tearing energy. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008 [source] Effects of the vulcanizing reagent addition on the properties of CNTs/SBR powder compositesJOURNAL OF APPLIED POLYMER SCIENCE, Issue 3 2007Xiangwen Zhou Abstract Vulcanizing reagent (VR) suspensions with different sulfur additions were mixed with CNTs suspensions and SBR latex, and then powder CNTs/SBR (PSBR) composites were prepared by spray-drying process. Investigations showed that VR additions have significant influences on the properties of CNTs/PSBR composites. With the increment of VR additions, glass transition temperature (Tg) of the composites increased gradually, and reached the maximum when the sulfur addition was 4.0 phr, and then it would decrease if the sulfur addition continued to rise. The elongation at break of the vulcanizates decreased linearly. The tensile strength and hardness reached the maximum when the sulfur addition was 4.0 phr, and almost kept constant when the addition continued to rise. Yet the tear strength reached the maximum when the addition was of 2.5 phr, and then decreased slightly when the addition exceeded 4.0 phr, which was corresponding to the structure designability of the composites affected by the sulfur aggregates in the matrix. Under different temperatures, when the vulcanizing temperature was 150°C, the vulcanizing speed was proper, vulcanizing time was prolonged, and the vulcanizing security was intensified. Compared with the vulcanization of carbon black/PSBR composites, more sulfur additions are needed in the vulcanization of CNTs/PSBR composites. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2007 [source] Blending of NR/BR/EPDM by reactive processing for tire sidewall applications.JOURNAL OF APPLIED POLYMER SCIENCE, Issue 4 2007Abstract The NR/BR blend compound formulations for tire sidewall applications contain a set of stabilizers added to prevent degradation mainly due to oxygen, ozone, and heat. 6PPD is the most effective and widely used antiozonant in tire compounds, but is a highly staining material causing a surface discoloration of the tire sidewall. Incorporation of 30 phr EPDM into blends of NR/BR improves the ozone resistance to the required level, without the need of 6PPD. The first two parts of this series have described a reactive processing technique applied to enhance the covulcanization and blend homogeneity, together with their characterization. In the present article, the properties of the NR/BR/EPDM blends prepared by both reactive and straight mixing are tested in comparison with those of equivalent conventional NR/BR compounds. The reactive NR/BR/EPDM blend vulcanizates show excellent tensile strength, elongation at break, tear strength, fatigue-to-failure, and ozone resistance in both static and dynamic conditions. The properties are equivalent or even superior to those of the conventional NR/BR tire sidewall compounds. The simple straight mixed NR/BR/EPDM blend vulcanizates distinctively possess inferior mechanical properties compared to those of the reactive mix. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 2555,2563, 2007 [source] Optimization of carbon black and nanoclay filler loading in chlorobutyl vulcanizates using response surface methodologyPOLYMER COMPOSITES, Issue 6 2009V. Sridhar In this article, an attempt has been made to study the applicability of using organo nanoclay (Cloisite 30B) and carbon black (HAF, N330) in chlorinated isobutyl isoprene rubber vulcanizates. Statistical design of experimentation was adopted so that maximum information can be obtained from a minimum number of experiments. Response surface methodology was applied successfully to rubber compound design using a rotatable central compound design. Compounding trials were carried out at design points, and the rubber vulcanizates were characterized for modulus, tensile strength, elongation at break, tear strength, bound rubber, and free volume parameters ,3 and I3. The experimental data was used to generate mathematical models by multiple linear regression analysis using MATLAB (version 6) package. The variability of the postulated models was tested by analysis of variance (ANOVA) and R2 tests and was found to be adequate. The accuracy of the models generated was tested by making an experimental trial. POLYM. COMPOS., 2009. © 2009 Society of Plastics Engineers [source] Recycling of silicone rubber waste: Effect of ground silicone rubber vulcanizate powder on the properties of silicone rubberPOLYMER ENGINEERING & SCIENCE, Issue 2 2003Arun Ghosh The silicone rubber vulcanizate powder (SVP) obtained from silicone rubber by mechanical grinding exists in a highly aggregated state. The particle size distribution of SVP is broad, ranging from 2 µm to 110 µm with an average particle size of 33 µm. X-ray Photoelectron Spectroscopy (XPS) and Infrared (IR) Spectroscopy studies show that there is no chemical change on the rubber surface following mechanical grinding of the heat-aged (200°C/10 days) silicone rubber vulcanizate. Addition of SVP in silicone rubber increases the Mooney viscosity, Mooney scorch time, shear viscosity and activation energy for viscous flow. Measurement of curing characteristics reveals that incorporation of SVP into the virgin silicone rubber causes an increase in minimum torque, but marginal decrease in maximum torque and rate constant of curing. However, the activation energy of curing shows an increasing trend with increasing loading of SVP. Expectedly, incorporation of SVP does not alter the glass-rubber transition and cold crystallization temperatures of silicone rubber, as observed in the dynamic mechanical spectra. It is further observed that on incorporation of even a high loading of SVP (i.e., 60 phr), the tensile and tear strength of the silicone rubber are decreased by only about 20%, and modulus dropped by 15%, while the hardness, tension set and hysteresis loss undergo marginal changes and compression stress-relaxation is not significantly changed. Atomic Force Microscopy studies reveal that incorporation of SVP into silicone rubber does not cause significant changes in the surface morphology. [source] Metallocene based polyolefin: a potential candidate for the replacement of flexible poly (vinyl chloride) in the medical fieldPOLYMERS FOR ADVANCED TECHNOLOGIES, Issue 9 2010M. C. Sunny Abstract A comparative assessment of the performance properties of metallocene polyolefin (m-PO) with those of plasticized poly (vinyl chloride) (pPVC) and ethylene vinyl acetate (EVA) copolymer having 18% vinyl acetate content (EVA-18), the two common polymers used for flexible medical products, is carried out. The preliminary evaluation of the processability, mechanical properties, and thermal stability of the new material, m-PO is described. The processability parameters like mixing torque and melt viscosity of m-PO are found to be comparable with those of pPVC and EVA-18. Mechanical properties such as tensile strength, elongation at break, and tear strength (TS) of m-PO are much higher than that of pPVC and EVA-18. Thermo gravimetric analysis (TGA) indicates that the thermal degradation of m-PO takes place only at temperatures above 340°C and can be processed at 170°C without much damage. Oxygen and carbon dioxide permeabilities of m-PO at three different temperatures (10, 25, and 40°C) are evaluated and compared with those of pPVC and EVA-18. It could be seen that the permeabilities of both the gases for m-PO at three temperatures were lower than those of pPVC and EVA. Biological evaluation of m-PO is carried out by assessing its cytotoxicity, hemolytic property, and blood clotting initiation. The cytotoxicity studies indicate that m-PO is non-toxic to the monolayer of L929 mammalian fibroblast cell lines on direct contact or the exposure of its extract. Non-hemolytic property of m-PO by direct contact as well as test on extract is revealed both in static and in dynamic conditions. Blood clotting time experiments indicate that the initiation of blood clotting due to m-PO is faster than that of pPVC and EVA-18. Copyright © 2009 John Wiley & Sons, Ltd. [source] Predicting the crease recovery performance and tear strength of cotton fabric treated with modified N -methylol dihydroxyethylene urea and polyethylene softenerCOLORATION TECHNOLOGY, Issue 5 2010Tanveer Hussain This study aimed at developing a model for predicting the crease recovery performance and tear strength of cotton fabric using modified N -methylol dihydroxyethylene urea, polyethylene softener, catalyst, curing time and curing temperature as the predictor variables. A quarter factorial design was constructed and, based on the experimental results, regression models were built to predict crease recovery angle and tear strength of the treated fabric. All experimental design and statistical analysis steps were implemented, using Minitab statistical software. [source] | |||||||||||||