• Elastomers and Composites
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• v.5 no.1
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• pp.111-118
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• 1970

• Elastomers and Composites
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• v.35 no.2
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• pp.115-121
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• 2000

In comparison with thermosetting rubber, thermoplastic elastomer (TPE) has various advantages such as simple processing, short cycle time and recycling of scrap. These advantages can lead to development of the high value-added rubber products due to reduction of the waste material, manufacturing cost and the defected product. This article involves a dynamic vulcanization method for EPDM/polypropylene blend, and the manufacturing of a fixed glass weather-strip by glass insert molding method using the blend. In order to investigate mechanical properties of the product, tensile strength, elongation, hardness and specific gravity were measured. Also morphological study was carried out using SEM. Developments of an efficient system of production and automatic process by molding of TPE and glass simultaneously are expected.

• Elastomers and Composites
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• v.46 no.4
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• pp.318-323
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• 2011

To recycle the waste tire rubber powder, rubber powder composite for waterproof sheet was prepared, and analyzed the effect of the kind of resin and the amount of crosslinking agent on the mechanical property of the composites. The elongation-at-break of the PE composite increased more than 3 times as EPDM was added into rubber composites. As the content of the crosslinking agent increased, the tensile strength of composite increased as well. When recycled polypropylene was used, the increase in composite's tensile strength was more than 3 times. Therefore to use the recycled PP in composite is more effective rather than PP in term mechanical properties.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.25 no.5
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• pp.193-198
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• 2015

In the study, electroless Ni-plating on flexible ethylene-propylene-diene-monomer (EPDM) rubber sheets for the application of an insert block for shielding electromagnetic interference of multi cable transit (MCT) systems was investigated. Ni crystallinity and adhesion have been found to vary with processing parameters such as pH and temperature of the plating bath. It was shown that Ni-films having the high crystallinity and optimum electric conductivity were obtained on EPDM rubber sheets under pH 7 and 8 at $60{\sim}70^{\circ}C$. The conductive Ni-plated EPDM rubber prepared at pH 7 at $70^{\circ}C$ showed the enhanced adhesion and electric conductivity, and the high electromagnetic interference shielding effect in the 400 MHz~1 GHz range.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.05c
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• pp.62-65
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• 2001

The effects of accelerated UV radiation on EPDM used for a polymeric insulator were investigated by contact angle, surface voltage decay after corona charging, SEM-EDX, ATR-FTIR and XPS. EPDM occurs as loss of hydrophobicity by UV treatment, which followed by surface cracking and chalking. The surface voltage decay on UV-treated EPDM show that the shorter decay time corresponded to the treated samples with a longer UV exposure time. The surface oxygen and aluminum content were found to increase and carbon decrease, as is observed in EDX analysis. The ATR-FTIR and XPS indicated that C-C and C-H groups decreased and the highly oxidized carbon bonds such as C-O, C=O and O-C=O increase with time. Also, the effects of surface charges on hydrophobicity based on our results is discussed.

• Elastomers and Composites
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• v.37 no.2
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• pp.107-114
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• 2002

This paper discusses the accelerated heat aging tests were carried out to predict the useful life of EPDM isolating rubber components of ventilation fan motor for clean room. 20% compression set results changes as the threshold are used for assessment of the useful life and the time to threshold value were plotted against reciprocal of absolute temperature to give the Arrhenius plot. The useful life at variable temperatures and activation energy are obtained from the Arrhenius relationship. An accelerated test program to assess useful life can be represented an appreciable investment in time was designed. We also considered the effect of antioxidant agents.

• Transactions of the Korean Society of Automotive Engineers
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• v.19 no.4
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• pp.107-113
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• 2011

Coolant rubber hoses for automotive radiators under thermal and mechanical loadings can be degraded and thus failed due to the influences of the locally formed electricity. In this study, an advanced test method was developed to simulate the failure problem of the rubber hose. For carbon black filled EPDM (ethylene-propylene dine monomer) rubber used as a radiator hose material the ageing behaviors by the electro-chemical stresses combined with a tensile strain were analyzed. As the tensile strain increased, the current of the rubber specimen reduced indicating an increase of the internal defects and electrical resistance of the rubber specimen. Elongation at break and IRHD hardness rapidly decreased with increasing the ageing time. Both electro-chemical stress and mechanical tensile stress clearly accelerated the degradation of EPDM rubber.

• Elastomers and Composites
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• v.22 no.3
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• pp.213-218
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• 1987

In this study, the rheological properties of a partially valcanized black filled EPDM were investigated as a function of degree of crosslinks using capillary rheometer. In order to obtain the samples having various degree of crosslinks between 0 and 6 percent, the vulcanization kinetics was also studied by Monsanto rheometer. The results showed that the die swell ana the pressure drop at the capillary entrance and exit increase nearly linearly with the increase in degree of crosslinks. However, melt fracture occurred at a lower shear rate for the samples of higher degree of crosslinks. These results were discussed in terms of the melt elasticity produced at the entrance region of capillary by the partial vulcanization. It is also interesting to note that the fluctuation of die swell during the practical extrusion or calendering process in the factories can be caused by the partial vulcanization occurred during the process.

• 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.

• 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.