• Elastomers and Composites
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• v.36 no.3
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• pp.169-176
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• 2001

Ethyl-branched polyethylene[PE(2)] containing 2mole% ethyl branch and three ethylene-propylene rubbers(EPR's) haying the same ethylene(E)-propylene(P) molar ratio(E/P=50/50) with different stereoregularity, that is, random EPR(r-EPR), alternating-EPR(alt-FPR) and isotactic-alternating-EPR(iso-alt-EPR) were mixed for the investigation of their properties depending on the stereoregurarity. The three blends were immiscible at room temperature, and showed the simple additivity effect in density behavior. The melting point depression with blend composition increased in order of PE(2)/r-EPR>PE(2)/alt-EPR>PE(2)/iso-alt-EPR. In the tensile test, this blend systems have the lowest value or the breaking strength at FE(2) fraction of 0.5. This phenomenon results from the greastest separated phase morphology at this blend composition.

• Clean Technology
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• v.15 no.3
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• pp.180-185
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• 2009

The ethylene-propylene rubber (EPDM) scrap generated from automobile weatherstrip manufacturing process was used to make a thermoplastic elastomer through blending with polypropylene. The surface activated EPDM powder was obtained by the high temperature and shear pulverizer. The addition of surfactant resulted in more surface activated EPDM powder and the optimum loading amounts of surfactant was 1.5 phr. Maleic anhydride was grafted onto polypropylene by reactive blending to give functionalized polypropylene. The wetting property between EPDM scrap and polypropylene was improved by the addition of poly (ethylene-co-acrylic acid) as a compatibilizing agent. Poly(ethylene-co-acrylic acid) decreased the surface tension of polypropylene and thus would contribute to the wettability with EPDM powder.

• Fire Science and Engineering
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• v.25 no.6
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• pp.190-195
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• 2011

Effects of ethylene-propylene diene monomer (EPDM)/polypropylene (PP), zinc oxide, stearic acid, and clay on the combustive properties based on EPDM/PP were investigated. The EPDM/PP/clay nanocomposites was compounded to prepare specimen for combustive analysis by cone calorimeter (ISO 5660-1). It was found that the combustive properties in the nanocomposites decreased due to the fire resistance compared with unfilld EDPM/PP. The nanocomposites showed the lower peak heat release rate (PHRR) than that of virgin EPDM/PP, while stearic acid for softening ruber increased the mean heat release rate (MHRR) by itself, combustible.

• Elastomers and Composites
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• v.37 no.2
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• pp.79-85
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• 2002

Ethyl-branched polyethylene [PE(2)] containing 2mole% ethyl branch and three ethylene-propylene rubbers (EPR's) having the same ethylene(E)-propylene(P) molar ratio(E/P=50/50) with different stereoregularity, that is, random EPR (r-EPR), alternating-EPR (alt-EPR) and isotactic-alternating-EPR (iso-alt-EPR) were mixed for the investigation or their properties depending on the stereoregularity. Crystallinity of the prepared blends decreased with increasing content of amorphous EPR because of a decrease in both the degree of annealing and kinetics of diffusion of the crystallizable polymer content. With blend composition, crystallinity was reduced with the stereoregularity in EPR. The thermodynamic interaction parameter(x) for the three blend systems approximately equals to zero near the melting point. These systems were determined to be miscible on a molecular scale near or above the crystalline melting point or the crystalline PE(2). From the measurement of $T_m$ vs. $T_c$, the behavior of PE(2) is mainly due to a diluent effect of EPR component. The spherulite size measured by small angle light scattering (SALS) technique depended upon blend composition, and stereoregularity of EPR. The size of spherulite was enlarged with the content of rubbery EPR and the decrease of stereoregularity in EPR.

• Journal of Adhesion and Interface
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• v.2 no.4
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• pp.24-31
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• 2001

Polypropylenes(PP) with different melt index values were mixed with ethylene-propylene rubber(EPR) or ethylene-propylene diene monomer rubber(EPDM) and an ethylene copolymer containing carboxylic acid group in a twin screw extruder. Then test specimens were prepared from the pellets of the blends with an injection molding machine. The mechanical properties and morphology of fractured surfaces were measured. Relative peak intensities of carboxylic acid group on the specimen surface were measured with an attennuated total reflection infrared spectrometer (ATR-IR) and compared with each other. The blend specimens were found to have the gradient morphology of rubber domains in PP matrix in the core region and PP skin layer. The blends containing PP of higher melt index showed greater content of ethylene copolymer containing carboxylic acid on the surface when the relative peak intensities of ATR-IR for carboxylic acid were compared. As the melt index values were increased, the decrease tendency in mechanical propeties such as tensile strength and impact strength was more significant for PP/EPR blends than PP/EPDM blends.

• Elastomers and Composites
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• v.48 no.3
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• pp.195-200
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• 2013

The main objective of this study is to improve abrasion resistance and wet slip resistance of thermoplastic polyurethane (TPU) by blending with ethylene-propylene-diene monomer rubber (EPDM) or polybutadiene rubber (BR) for the application of the footwear outsole materials. With addition of 10 wt% of EPDM or BR, TPU/EPDM and TPU/BR blends exhibited higher NBS abrasion resistance, tensile properties and wet slip resistance than TPU. However, with further increasing content of EPDM and BR, abrasion resistance and tensile properties of the blends decreased. Improvement in abrasion resistance and tensile properties with 10 wt% of addition of EPDM or BR may be due to better microphase separation of TPU.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.22 no.9
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• pp.837-844
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• 2012

We considered an approach in terms of materials for improvement of insulation performance of vehicle rubber hoses. Ethylene propylene rubber(EPDM) for heater hoses in cooling system and acrylic rubber(AR) for intercooler hose in intake system were chosen for mixing for the vibration and noise performance. We modified EPDM and AR through changing compound of base polymer, reinforcement fillers and additives. Dynamic mechanical analysis(DMA) was used to measure viscoelastic properties such as shear modulus and loss factor($tan{\delta}$). Vehicle acceleration test was also conducted to observe indoor changes in insulation performance of hoses.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2013.06a
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• pp.120-121
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• 2013

Recently, our country is to be diversification a leisure activity and tourism form by income level rise and traffic circumstance improvement. But Basic facilities expropriated these leisure activities have built an insufficient condition. Also, Building a facility, Introduced tools and materials import the whole quantity. Therefore, In this paper, it builds a tension mooring unit to use EPDM and Kevlar R29 and it develops a domestic marine circumstance through reliability based on robust design. It contributes to marine leisure culture activation and industry development.

• Elastomers and Composites
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• v.46 no.3
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• pp.251-256
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• 2011

Effect of poly(propylene-co-octene) as a compatibilizer in toughened polypropylene/ poly(ethylene-co-octene) (EOC) was investigated. The EOCs used were metallocene catalyzed commercial linear low density polyethylene and they are elastomeric materials. The poly(propylene-co-octene) was synthesized by metallocene catalyst in our laboratory to be used as a compatibilizer in PP/EOC blends. PP/EOC blends without compatibilizer shows very low mechanical properties in specimens with weldlines while incorporation of a compatibilizer significantly increases the mechanical properties of specimens with weldlines. However, compatibilized PP/EOC blends does not show increased impact property in a weldline free specimen and it is attributed to low molecular weight of the poly(propylene-co-octene) synthesized in present study. It is expected that the poly(propylene-co-octene) having increased molecular weight provides very good performance as an effective compatibilizer in toughened polypropylene/EOC blends.

• Elastomers and Composites
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• v.47 no.3
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• pp.201-209
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• 2012

Grommet is one of the Automotive rubber components and is made from EPDM(Ethylene Propylene Diene monomer M-class) rubber and the nonlinear hyperelastic material properties of rubber are important to predict the behavior of rubber product. In this study, the stable stress-strain relations were obtained from the uni-axial tension test and the equi-biaxial tension test. Finite element analysis for grommet was carried out and heat aging test for the lifetime prediction of grommet was introduced.