• Polymer(Korea)
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• v.37 no.5
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• pp.571-578
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• 2013

Polyamide12 (PA12) is blended with ethylene propylene diene rubber (EPDM) at various compositions in the presence of maleated EPDM (mEPDM) to afford blend materials having the characteristics of thermoplastic elastomer (TPE). The EPDM/PA12 melt-blends are further irradiated with electron-beam (e-beam) at 0~100 kGy dosage, yielding selective crosslinking between EPDM chains while retaining melt-processibility originated from PA12 phase. mEPDM acts as a compatibilizer and affords additional improvements in mechanical properties of the EPDM/PA12 blend. With 25 kGy of e-beam irradiation and mEPDM, the EPDM/PA12 blends successfully exhibit TPE behaviors with reasonable elastomeric and mechanical properties.

• Elastomers and Composites
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• v.34 no.1
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• pp.20-30
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• 1999

In this study, binary polyamide 6,6(PA 6,6)/ethylene-propylene rubber(EPM) or EPM-g-maleic anhydride(EPM-g-MA) blends and ternary PA 6,6/EPM/EPM-g-MA blends with various elastomer content were prepared in order to investigate the degree of influence of elastomer content and average particle size, morphology, and distribution of dispersed elastomer on mechanical and thermal properties of blends. According to the results, notched Izod impact strength and relative crystallinity of binary blends modified with EPM-g-MA as well as average particle size and distribution of dispersed elastomer in such blends were more improved than those of binary blends modified with EPM. Notched Izod impact strength of blend whose composition ratio(wt % ) was 70:30(PA 6,6 : EPM-g-MA) was the highest among the binary PA 6,6/EPM-g-MA blends. The impact strength was increased by 25 times and its relative crystallinity was increased by 7 times when compared with those of polyamide 6,6. In the case of ternary PA 6,6/EPM/EPM-g-MA blend of which composition ratio was 70:15:15(PA 6,6:EPM:EPM-g-MA), the elastomer was finely distributed with the average particle size of $0.56{\mu}m$. The Izod impact strength of this blend was the highest of all blends prepared with different elastomer content.

• Journal of Electrical Engineering and Technology
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• v.9 no.3
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• pp.984-990
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• 2014

Polymers are the most commonly used di-electrics because of their reliability, availability, ease of fabrication and cost. The commercial and industrial demand for advanced polymeric materials which are capable of being used in harsh environment is need of the hour. The study of the effect of electron beam irradiation on polymeric materials is an area of rapidly increasing interest. This paper discusses the resultant beneficial effects of electron beam irradiation on the SiR-EPDM blend having 50:50 composition. The changes in mechanical and electrical properties of SiR-EPDM blend which are exposed to three different doses of electron beam radiation namely 5 Mrad, 15 Mrad and 25 Mrad are presented. The irradiated blends are analyzed for their electro-mechanical and physico chemical properties. The electrical changes induced by irradiation are investigated by arc resistance, surface resistivity and volume resistivity measurements as per ASTM standards. The mechanical changes are observed by the measurement of tensile strength and elongation at break. Physico chemical investigation has been done using the FTIR, in order to investigate the irradiation induced chemical changes.

• Elastomers and Composites
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• v.30 no.2
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• pp.105-111
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• 1995

The thermal decomposition of the paper sludge with poly (acrylonitrile-butadiene-styrene) was using a thermal analysis techniques in the stream of nitrogen gas of 30ml/min at various heating rates from 4 to $20^{\circ}C/min$. The mathmatical, derivative and integral method were used to obtain values of activation energy of decomposition reaction. 1. The values of activation energy evaluated by derivative and Intergral method were consistent with each other very well. 2. The maximum value of heat of decomposition evaluated by DSC method was 10.120cal/g at weight ratio of paper sludge/ABS=20/80. 3. The thermogravimetric trace curve agreed with the theoretical equation.

• Elastomers and Composites
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• v.50 no.4
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• pp.245-250
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• 2015

Recycling of ethylene-propylene-diene terpolymer (EPDM) scrap was tried by blending with polypropylene (PP). EPDM scrap powder was prepared by shear pulverization process at high temperature, which may lead to selective chain scission induced by difference in the critical elastic coefficient. On the other hand, EPDM scrap powder was prepared by adding a selected reclaiming agent during shear pulverization process at high temperature. Terpene as a bonding agent was then introduced to improve adhesion property. PP, used as a matrix for manufacturing thermoplastic elastomer, was modified by the incorporation of dicumyl peroxide and maleic anhydride. The functionalized EPDM and modified PP were blended and cured dynamically at $190^{\circ}C$. The blend materials prepared in this study showed the comparable results to those of conventional TPE in terms of tensile and flow properties. Also, the odor component of recycled EPDM was analyzed using GC-MS.

• Journal of Adhesion and Interface
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• v.2 no.4
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• pp.32-38
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• 2001

Effects of the ratio of rubber composition on covulcanization and ozone resistance were studied in this study. Specimens used in this study were rubber compounds(specimen-A) blended with various ratio of NR, SBR, BR, IIR, and EPDM, unsaturated rubber compounds(specimen-B) with NR/BR/SBR, and saturated rubber compounds(specimen-C) with NR/IIR/EPDM. PAD adhesion specimen was prepared from vulcanizing specimen-A and B, and specimen-A and C, respectively. Using same adhesion specimen, peel strength was measured and tested ozone resistance. In specimen-A, peel strength was higher with increasing NR ratio for NR and BR contained blends. In other specimen-A containing NR and SBR, the peel strength was also increased with increasing SBR ratio. NR/BR/IIR/EPDM rubber compounds had also better adhesion property than NR/SBR/IIR/EPDM compounds. As more unsaturated rubber was blended, the peel strength was higher but ozone resistance was worse. Optimum ratio of unsaturated and saturated rubbers for the peel strength and ozone resistance was 60/40.

• Elastomers and Composites
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• v.33 no.4
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• pp.274-280
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• 1998

Order of reaction, rate constant, activation energy for vulcanization reaction, crosslinking density, and elastic constant of the network produced by sulfur curing were investigated on the SBR/BR blends containing silica and carbon black under same cure system. The reaction order was shown to be first order regardless of filler types. The carbon black filled rubber compounds showed higher rate constant compared to silica filled compounds. But activation energy appeared to be same regardless of filler type and rubber blend ratio. The crosslinking density and elastic constant is higher in the carbon black filled compound compared to silica filled compounds because of strong interaction between rubber and carbon black. On the other hand, crosslinking density and elastic constant were decreased with increasing the butadine rubber content in rubber blends. From the comparison of combined sulfur content in the vulcanized rubber, sulfur content in the silica filled compound become constant 20min later after reaction initiates but sulfur content in the carbon black filled compound become constant 10min later after reaction starts. The silica compound has a longer induction time ($t_2$) and optimum cure time($t_{90}$) compared to those of the carbon black filled compound.

• Elastomers and Composites
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• v.29 no.5
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• pp.431-435
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• 1994

For recycling of the waste tires, polyurethane binder mixed with the scrapped rubber powders which obtained from tread part of waste tire. This study covered the effect of the binder contents on the mechanical properties of the blend. We also studied the change of the properties after aging on properties compared with those of before aging. The curing reaction of the binder was also investigated in this study. We obtained conclusions the suitable binder content was 15phr in this system.

• Elastomers and Composites
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• v.31 no.2
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• pp.95-103
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• 1996

Nowadays, recycling of waste materials is one of great attention among all industries. Especially, the waste tires become a significant problem with increasing in a number of automobiles. For recycling of the waste tires, a polyurethane binder was mixed with the scrapped rubber powders obtained from tread part of the waste tire. This study covered the effect of processing conditions;curing temperature and curing time;on the mechanical properties of the blend. We also compared the experimental results from labors-tory scale with those from scale-up.

• Elastomers and Composites
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• v.58 no.1
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• pp.17-25
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• 2023

Abrasion tests of model tire tread compounds (NR and NR/BR blend compounds) were performed at different slip angles (1° and 7°) using a laboratory abrasion tester. The abrasion behavior was investigated by analyzing the worn surface and wear particles. The abrasion spacing formed on the specimen worn at the large slip angle of 7° was significantly narrower than that at the small slip angle of 1°, while the abrasion depth for the specimen worn at 7° was lower than that at 1°. The abrasion spacing and depth tended to be narrower and lower, respectively, as the BR content increased. The abrasion patterns were clearly visible on the outside of the specimen for the slip angle of 1° but not for 7°. The wear particles had a rough surface and there were numerous micro-bumps. It was found that the crosslink density affected the abrasion patterns and morphologies of the wear particles.