Characterization of irradiation modification of ethylene vinyl acetate/ epoxidized natural rubber/ halloysite nanotubes nanocomposites

摘要

Ethylene vinyl acetate (EVA)/ Epoxidised natural rubber (ENR50)/ Halloysite nanotubes (HNTs) nanocomposite were prepared using twin screw extruder at temperature profile of 120-150°C and rotor speed of 70 rpm. The compounds were injection molded to produce test specimens and exposed to electron beam (EB) radiation at 50-200 kGy dose range to induce crosslinking. EB radiation was perform under the acceleration energy, beam current, and dose rate of 2MeV, 2 mA, and 20kGy/pass, respectively. The effects of HNTs loading on the tensile, gel content, thermal and morphological properties of the EVA/ENR50/HNT nanocomposite were investigated before and after irradiation. The effects of crosslinking agents, N, N-mphenylenedimaleimide (HVA-2) and trimethylolpropane triacrylate (TMPTA) on nanocomposites were also examined. Prior to irradiation, no significant changes in tensile properties of the EVA/ENR50/HNT nanocomposite were observed upon addition of HNT. However, at 4 php HNT content, a good dispersion of HNT in EVA/ENR50 matrix was observed while agglomeration found to occur at 8 php HNT content. The thermal stability of the EVA/ENR50/HNT nanocomposite was increased as the HNT content increased. Upon irradiation, the gel content, tensile strength and thermal properties of the EVA/ENR50/HNT nanocomposites were increased with the increase of HNT content and irradiation dose due to the formation radiation induced crosslinking. The tensile strength of the EVA/ENR50/4HNT nanocomposites was improved with the addition of TMPTA and HVA-2 due to crosslinking. It can be proven from Scanning Electron Micrographs that the compatibility of EVA/ENR50/4HNT nanocomposites improved upon irradiation. The incorporation of HVA-2 and TMPTA found to play major role in EVA/ENR50/4HNT nanocomposite compatibilization upon irradiation.