• Elastomers and Composites
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• v.31 no.5
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• pp.341-346
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• 1996

The fracture mechanics investigation of the thermoplastic vulcanizates(TPV) from EPDM and PP/Ionomer ternary blends was performed in terms of the J-integral by measuring fracture energy via the locus method. The TPV from ternary blends consisting of EPDM, PP and ionomer were prepared in a laboratory integral mixer by blending and vulcanizing simultaneously. Vulcanization was performed with dicumyl peroxide (DCP) and the composition of EPDM and PP was fixed at 50/50 by weight. Two kinds of poly(ethylene-co-methacrylic acid) (EMA) lonomers were used. The J-integral values at crack initiation, Jc, of the dynamically vulcanized EPDM and PP/EMA Ionomer ternary blends were affected by the cation types $(Na^+\;or\;Zn^{2+})$ and contents(5-20wt%) of the added EMA Ionomers. The ternary blend containing 20wt% zinc-neutralized EMA Ionomer and 1.0phr DCP showed the highest Jc values of the blends.

• Elastomers and Composites
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• v.47 no.3
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• pp.231-237
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• 2012

This study measured the mechanical and damping properties of EPDM compounds including fillers. Semi-reinforcing furnace black (SRF), high abrasion furnace black (HAF) and acetylene black were used as fillers. Dicumyl peroxide (DCP) were used as curing agents. The measurements were conducted using a moving die rheometer (MDR), durometer, universal testing machine (UTM), compression set and dynamic mechanical analysis (DMA). The tensile strength and elongation at break increased with increasing SRF contents in EPDM compounds. However, they decreased with increasing the amount of acetylene black. In the inspecting temperature range, EPDM compound filled acetylene black had stable storage modulus. Furthermore, the tan ${\delta}$ of the EPDM compounds obtained was enhanced by compounding with acetylene black.

• 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.

• Elastomers and Composites
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• v.37 no.4
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• pp.211-216
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• 2002

The polymer-polymer interaction parameter, x 23t, of the styrene-butadiene polymer (SBR) and ethylene-propylene-diene terpolymer (EPDM) was investigated by observing the phase behavior of the ternary system of SBR/EPDM/solvent. The solvent used in this study was benzene acting as a good solvent for SBR but as a poor solvent for EPDM. Ternary solutions with various concentrations and mixing ratios of the two component polymers were separated into two phases by temperature change The cloud point curves (CPC) showed that the differerence of solvent affinities toward each polymer and the repulsive interaction between two polymers considerably affect the shape of CPC near 15℃. In the temperature range of 5℃ ~ 25℃, incompatible behaviours arised from both the difference of mixing ratios and concentration were clearly observed. Also the phase separation temperature greatly influenced on the composition of each separated phase. The calculated x 23t values from Flory-Huggins theory were in the range of 0.6301 ~ 1.0775, which suggest that the SBR/EPDM systems are incompatible.

• Elastomers and Composites
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• v.44 no.2
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• pp.122-133
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• 2009

Rubbers, such as natural rubber, polybutadiene, styrene-butadiene rubber, nitrile-butadiene rubber, chlorinated rubber and EPDM, have been continuously improved in response to a heavy demand and a new property requirement from industry. One of the best ways to realize the improvement is the modification of rubbers through chemical reactions, which produce materials with novel properties. In this review, chemical modification reactions of rubbers that contain carbon-carbon double bond units either in their main backbone or as a side group were briefly summarized. The chemical reactions introduce functional groups or functional polymer chains to polymer backbone, which transform a classical rubber to a highly functional material. Especially, we focused on a controlled/"living" radical polymerization techniques, with which a revolutionary broadening of the spectrum of the materials with well defined molecular weight, molecular weight distribution, chain end-functionality and architectures become possible.

• Elastomers and Composites
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• v.51 no.3
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• pp.175-180
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• 2016

Influence of amino acidic chemical on properties of maleic anhydride-grafted ethylene-propylene-diene terpolymer/zinc oxide (EPDM-g-MAH/ZnO) composites was investigated. 4-Aminosalicylic acid (ASA), 4-amino-2-methoxybenzoic acid (AMBA), 12-aminolauric acid (ALA), and glutamine (Gln) were employed as the amino acidic chemicals. Though small quantity (0.5 phr) of the amino acidic chemical was added to the EPDM-g-MAH/ZnO composite, the properties were notably changed. By adding the amino acidic chemical, the percent crystallinity and apparent crosslink density were reduced. Order of the percent crystallinity was related to that of the $pK_a$ values of amino acidic chemicals. By adding the amino acidic chemical, the basic tensile properties were on the whole improved. The experimental results were explained by the $pK_a$ values of amino acidic chemicals, change of zinc ionomer formation, and interactions between the additive and EPDM-g-MAH chain.

• Polymer(Korea)
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• v.29 no.2
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• pp.151-155
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• 2005

The effect of acid-base treatments of carbon blacks (CBs) was investigated in the mechanical properties of CBs/rubber composites. The surface characteristics of the CBs were determined by the pH, acid-base values, and surface energetics. Their mechanical properties of the composites were also evaluated by the crosslink density $(V_e)$ and tearing energy (T). As an experimental result, acidically treated CBs led to the increase of the specific component $({\gamma}s^{sp})$, resulting in decreasing the mechanical properties of the composites. However, basically treated CBs showed a higher value of the dispersive component $({\gamma}s^L)$ than that of the untreated or acidically treated CBs. It was also found that the interaction of the CBs-rubber was improved, resulting in the improvement of the crosslink density and mechanical properties of the composites. It was then remarked that the acid-base characteristics of the CB surfaces made an important role in improving the physical properties of the rubber matrix composites.

• Polymer(Korea)
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• v.34 no.5
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• pp.430-433
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• 2010

The gasket materials of for the lithium ion battery requires chemical resistance to electrolyte, electrical insulating, compression set, anti-contamination and low temperature property. To check the special characteristics of fillers which are applied to rubber for gasket, compound of EPDM, NBR and FKM (fluoro elastomer) were made by adjusting weights of carbon black and silica additive. Using these compounds, we had done tests of long-term stability against electrolyte, compression set and low-temperature property with considering operating condition of the lithium ion battery. From this test, we investigated the physical and chemical characteristics of rubber with using of carbon black and silica additive in each.

• Elastomers and Composites
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• v.42 no.4
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• pp.249-258
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• 2007

In this study, the EPDM powder which was surface activated by high temperature and shear pulverization process was prepared and the mechanical properties and odor material analysis were investigated. Analysis for particle size and size distribution of waste of the EPDM powder has been performed. The waste EPDMs used in this study were 4 types of solid, sponge, solid+sponge, and solid+metal. According to the results, the solid type showed the smallest particle size among the 4 types of EPDM powder. Effective surface devulcanization of EPDM powder could be obtained by the addition of the reclaiming agent. The dicumyl peroxide was considered as the best crosslink agent for dynamic vulcanization when the surface activated EPDM powder was blended with polyolefin in order to make TPE. Also, the optimum amounts of DCP was 6 phr in terms of surface crosslink reaction and mechanical properties of EPDM powder. The processes of water adsorption and rose oil addition were employed to remove the odor of EPDM powder caused by reclaiming agent. The GC/MS was used to analyze the odor compounds.

• Elastomers and Composites
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• v.42 no.4
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• pp.232-237
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• 2007

We examined the properties of compound and made compound of the optimum state using the properties of each material to evaluate suitability of FKM, VMQ, EPDM, NBR with gasket for fuel cell which is in general use with the material of gasket. It could be found from the compound made with setting the optimum state that NBR is worse than FKM in the chemical property of matter for a long term, and VMQ is worse than FKM in the elution of a metal ion, and EPDM is worse than FKM in the permeability of gas. As a result of leak evaluation of gasket for fuel cell with using FKM, it appeared leak in short time when contracting pressure is getting lower and sealing pressure is getting higher. And as a result of the life prediction with using Arrhenius model, we could predict that it is possible to continuously drive for 60,000 hours.