Investigation on the influence of crosslink promoter on the irradiation crosslinking, dynamic mechanical property and thermal stability of ethylene vinyl acetate (EVA)atural rubber (SMR L)/organoclay nanocomposites

摘要

Electron beam crosslinked EVA/SMR L/organoclay nanocomposites had been produced by using a crosslink promoter, TMPTA. The EVA to SMR L ratio was fixed at 50:50 and the organoclay loading used was 2 phr and 8 phr. When the nanocomposites were irradiated up to 200 kGy without TMPTA, the gel fraction was below 55%, but with addition of 3 phr TMPTA the gel fraction increased to 80%. Different level of irradiation dose also was found to form different phase morphology on the nanocomposites as shown in the SEM micrographs. Analysis on FT-IR spectrum proved that the addition of TMPTA improved the crosslinking and grafting, whereas incorporation of organoclay reduces oxidative degradation of the nanocomposites. DMA analysis showed that both storage modulus and glass transition values increased with addition of TMPTA at all irradiation doses. However, the improvement of thermal decomposition temperatures of nanocomposites with TMPTA were lower compared to non-irradiated nanocomposites.