Electron beam initiated grafting and crosslinking of ethylene vinyl acetate copolymer .1. Structural characterization

Electron beam irradiation of Ethylene vinyl acetate, EVA (VA content 12, 28 & 45%) copolymer was carried out in presence of trimethylolpropane trimethacrylate (TMPTMA) and triallyl cyanurate (TAG) and the structure of the modified copolymers was determined with the help of IR spectroscopy and gel content measurements. The IR absorbance peak at 1640 cm(-1) disappears at lower radiation dose indicating that the grafting and crosslinking reactions take place through double bonds. Some carbonyl groups are formed during irradiation. The concentration of carbonyl group increases with the radiation dose and the level of multifunctional monomers. The grafting level of TAC onto EVA determined from IR absorbance peak at 1565 cm(-1) remains almost constant with the variation of radiation dose and increases with TAC level. The gel content increases with radiation dose, but changes marginally with TMPTMA and TAC levels. The percent gel content increases linearly with vinyl acetate content in EVA.