• Elastomers and Composites
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• v.9 no.1
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• pp.5-13
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• 1974

The characteristics of IR and IR blended elastomers, for footwear by means of blending with NR and SBR, have been studied. The results obtained were as follows: 1. The mastication of IR was almost not required, where as NR and SBR are necessary. Therefore mixing time was much reduced because of speedy filler feeding. 2. Disadvantage of low Mooney viscosity was covered by blending with NR and SBR, and by loading filler. Superior flow property in comparison to other polymers was worthy and valuable in providing formulas for mould flow, 3. The elongation property of green stocks and vulcanizates was shown smooth surface for extruded and calendered stocks, and facilitated fabrication processes. 4. Because of slow vulcanization, IR is required to control vulcanization time by adding proper accelerators. This property, in turn, made possible to improve the storing stability of green stocks by controlling scorch time.

• Elastomers and Composites
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• v.17 no.2
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• pp.77-90
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• 1982

The purpose of this study is to get comparative results on the combined antioxidant systems comprised of MHPPD with IPPD, MHPPD with PBN and MHIPPD with MB when they are individually added to NR and SBR compound. Vulcanization characterstics and physical properties of the combined antioxidants have been studied by means of the Mooney viscometer, the Monsanto disc rheometer and so on. According to the test results, MHPPD with IPPD system has shown faster cure rate, better optimum cure time and shorter scorch time than other systems. The vulcanizate comprised of the MHPPD with IPPD antioxidant system has taken advantage of heat resistance, fluid resistance and antiozone resistance.

• Elastomers and Composites
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• v.3 no.1
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• pp.32-38
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• 1968

The physical properties of NR-SBR and NR-BR blends were studied. 1. In blending, tensile strength decreased with increase in synthetic rubber contents. It was most effective when the ratio of NR/Syn. R is 75/25. 2. Tensile strength decreased with order of NR, SBR and BR and modulus after aging is proportional of synthetic rubber contents. 3. Elongation is less influenced by synthetic rubber ratio that on the other hand, the decrease of elongation is proportional to synthetic rubber contents after aging. 4. Hardness decreased with increase in the synthetic rubber contents and on the other hand, the hardness increased after aging.

• Applied Chemistry for Engineering
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• v.29 no.4
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• pp.399-404
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• 2018

This study compared the tackiness and adhesion of different tire tread compounds and rubber cements before and after vulcanization. The tackiness of natural rubber (NR) cement was the highest for all tread compounds before vulcanization, and the decrease in tackiness of NR cements over time was smaller than that of synthetic rubber cements. The tackiness before vulcanization was affected by the glass transition temperature of the rubber used in the cement and the decrease in tackiness over time of NR was smaller compared to that of using the synthetic rubber. The adhesion of NR-based cements after vulcanization was high for NR tread compounds but low for synthetic rubber tread compounds. On the contrary, the adhesion of emulsion (SBR) and solution SBR cements was high on all tread compounds which was shown to be higher when the rate of vulcanization of cement rubber was lower.

• Elastomers and Composites
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• v.6 no.2
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• pp.73-79
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• 1971

As a series of the studies of EPDM-Polymer blends, the experiments are concentrated to the investigation of the physical properties of the EPDM-SBR blends. The results are shown as follows: 1. Tensile strength decreased with increase in EPDM contents and the decreasing value was good results than NR blending. 2. It was found that the aging were much improved after blending and experiments data was good results than NR blending.

• Composites Research
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• v.16 no.2
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• pp.18-25
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• 2003

The tensile properties of short nylon6 fiber reinforced NR and SBR have been investigated as functions of fiber aspect ratio(AR), diameter ratio(DR), interphase condition, and fiber content. The tensile strength increased with increasing fiber AR(20 min.) and good interphase conditions. The short-fiber(DR=3 and AR=20 min.) reinforced SBR did not show the dilution effect for all interrhase conditions. And the short-fiber(DR=3 and AR=20min.) reinforced NR did not show the dilution effect except for the no-coating. The tensile moduli were significantly improved due to fiber AR. fiber content, and good interphase at same DR. The better interphase condition showed the higher pull-out force at same DR. Also, the stress analysis near the fiber end carried out using axisymmetric FEA to be convinced of the reinforcing mechanism. It is found that the fiber AR, interphase and DR have an important effect on tensile properties.

• Journal of environmental and Sanitary engineering
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• v.15 no.4
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• pp.123-133
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• 2000

The kinetic analysis was carried out for commercial rubbers such as NR, IR, BR, SBR 1500, and SBR 1700. Kinetic analysis for the commercial rubbers was performed using the thermogravimetric method, with which the activation energies of NR obtained by Kissinger, Friedman, and Ozawa's method were 195.0, 198.3 and 186.3kJ/mol, whereas that of SBR 1500 were 246.4, 247.5 and 254.8kJ/mol, respectively. It was shown that the yield of pyrolytic oil was generally increased with final temperature increasing, yet slightly decreased or increased over $700^{\circ}C$. Considering the effect of heating rate, it was found that the yield of pyrolytic oil was not consistent for each sample. The number average molecular weight of SBR 1500 was in the range of 740~2486. The calorific value of SBR 1500 was 39~40kJ/g, which were made comparative study of the conventional fuel such as kerosene, diesel, light fuel, and heavy fuel. Therefore it was essential that the selection of the suitable kinetic model and the mathematical solution because of the difference in parameters obtained from each method. It was proposed that the range of $600~700^{\circ}C$ in final temperature and high heating rate due to short run time. It was suggested that the pyrolytic oil be available to use to the fuel.

• Elastomers and Composites
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• v.16 no.1
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• pp.3-13
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• 1981

The purpose of this dissertation is to study the physical properties of cellular rubber products for industrial use. Vulcanization characteristics were investigated by usingcure curve that had obtained by means of Rheometer. The results of physical properties, vulcanization characteristics and foaming states are as follows. 1. The test results for vulcanization characteristics of NR compounds indicated that in the recipe R-1. When accelerator D is used, the optimum conditions of vulcanizate are obtained, while formula R-2 and R-3 have shown higher torgue at curing time, $1{\sim}2$ minutes. Cellular rubber product test in terms of compression set and compression deflection has also met the requirements of SAE. 2. For SBR compounds, S-1 formula was the best in terns of vulcanization characteristics, and for the blowing structure of cellular rubber products, formula S-3 in which accelerator M is added was fair. All other test results, such as compression set and compression deflection properties met SAE requirements. 3. NBR compound (N-1) including accelerator TT was the best in terms of vulcanization characteristic and also blowing structure. All other properties listed above met requirements, particulary for oil resistance test. 4. In the test of EPDM compounds, when mixed accelerator, M and TT, is used(formula E-1) the best results were obtained. Since EPDM is hydrocarbon elastomer, oil resistance test failed. All other properties met the requirement specified in SAE.

• Elastomers and Composites
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• v.38 no.2
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• pp.103-121
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• 2003

The application of powerful ultrasound to rubber recycling is a very recent field of study. An ultrasonic field creates high frequency extension-contraction stresses by acoustic cavitation. The breakdown of rubber network occurs primarily around pulsating cavities due to the highest level of strain produced by high-power ultrasound. Stronger reductions of cross-link density were observed at a higher pressure, indicating an important role of pressure during ultrasonic recycling. Visible bubbles were observed during ultrasonic treatment as a proof of acoustic cavitation. Shearing effect has a significant influence on improving the efficiency of ultrasonic treatment. After the ultrasonic treatment, the cross-link densities of NR/SBR blends were lower than those of NR and SBR due to the reduced degree of unsaturation and chemical reactions. Carbon black fillers increase the probability of bond scission during ultrasonic treatment, due to the restricted mobility. The mechanical properties of ground tire rubber (GRT)/HDPE blends were improved by ultrasonic treatment and dynamic revulcanization. Ultrasonic treatment of GRT in the presence of HDPE matrix was found to give better mechanical properties due to the chemical reactions between rubber and plastic phases.

• Journal of environmental and Sanitary engineering
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• v.15 no.4
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• pp.98-104
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• 2000

Commercial rubber(IR, NR, BR), SBR, and tire were degraded by thermal degradation process. The oil yield of rubbers and tire ranges about 37~86%, it was increased with increase of operation temperature in pyrolysis. And the yield of pyrolytic oil was increased with increase of heating rate. The maximum oil yields of IR, NR, BR, SBR, and tire were 80, 73, 83, 86 and 55% each at $700^{\circ}C$ with a heating rate of $20^{\circ}C$/min, respectively. The pyrolytic oil components were consisted of about 50 aromatic compounds. The calorific value of purolytic oil of commercial rubber, SBR, and tire was measured by calorimeter, it was 39~40 kJ/g. The BET surface area of pyroblack was $47~63m^2/g$. The optimum condition of pyrolysis was operating temperature of $700^{\circ}C$ with heating rate of $20^{\circ}C$. Therefore, the pyrolytic oil and pyroblack are possible to alternative fuel and carbon black.