THE INFLUENCE OF THE BLOWING AGENT CONTENT ON THE PROPERTIES OF MICROPOROUS ELASTOMER MATERIALS

Abstract

For the preparation of elastomer materials, besides the rubber and cross-linking system, a lot of additives are used, in order to improve the physical-mechanical properties, reduce the costs and achieve particular properties of the final material. The amounts of cross-linking compound components, determine the exploitation properties of elastomer materials. Micro-porous elastomer materials are cross-linked macro-molecules with a cellular structure formed using blowing agents which form cells by releasing gases at higher temperatures. The most important properties of micro-porous elastomers are low density, excellent damping properties, owing to the cellular structure, as well as high strength versus mass. In this work, the influence of the blowing agent content on the physical-mechanical properties of micro-porous elastomers based on terpolymer poly(ethylene-co-propylene-co-2-ethylidene-5-norbornene) rubber (EPDM) cross-linked with sulfur and reinforced with carbon black particles, was investigated. The content of a chemical blowing agent (oxybis(benzenesulphonyl hydrazide)) was varied (1.3; 1.8 and 2.0 phr). Based on rheological measurements, the rubber compound curing behavior was determined. The density of the final materials shows significant differences depending on the blowing agent content in the prepared samples. It was assessed that prepared cellular elastomer materials are suitable for use in the fabrication of sealing profiles the automotive industry. The obtained elastomers with lower density can be used for the profile seals, as for, static parts that are not exposed to tangential impacts, while for the micro-porous seals of movable parts, higher density elastomers can be used.

Keywords

• microporous elastomers
• rubber
• blowing agent
• mechanical properties