Journal of Applied Polymer Science, Vol.93, No.5, 2379-2384, 2004
Polymerization conversion and structure of magnesium methacrylate in ethylene-vinyl acetate rubber vulcanizates
Ethylene-vinyl acetate rubber (EVM) filled with magnesium methacrylate (MDMA) was cured with dicumyl peroxide (DCP). The experimental results showed that the mechanical properties of MDMA/EVM vulcanizates were superior to those of high-abrasion furnace carbon black/EVM vulcanizates. The tensile strength of the MDMA/EVM vulcanizate could reach 22.5 MPa and the tear strength was 83.5 kN/m, whereas its elongation at break remained over 300%, even when the MDMA content was 50 phr. FTIR analysis confirmed that polymerization of MDMA occurred under the initiation of DCP, and the polymerization conversion of MDMA decreased with the increase of MDMA content. When the MDMA content increased from 10 to 50 phr, the conversion of MDMA in EVM decreased from 68 to 20%. SEM and TEM observations indicated that 20 mum particles of MDMA powder changed into about 20 nm particles during the curing process, and the finer particles dispersed evenly in the EVM vulcanizates. (C) 2004 Wiley Periodicals, Inc.
Keywords:ethylene-vinyl acetate rubber (EVM);polymerization;reinforcement;structure;curing of polymers