GRAFT-COPOLYMERIZATION OF N-VINYL-2-PYRROLIDONE ON DIMETHYL-SULFOXIDEPRETREATED POLY(ETHYLENE-TEREPHTHALATE) FILMS USING AZOBISISOBUTYRONITRILE INITIATOR

Poly(ethylene terephthalate) (PET) films were grafted with n-vinyl-2-p yrrolidone (n-VP) using an azobisisobutyronitrile (AIBN) initiator. Fi lms were pretreated in dimethyl sulfoxide (DMSO) for 1 h at 140 degree s C before the polymerization reaction was carried out. Variations of graft yield with time, temperature, initiator, and monomer concentrati ons were investigated. The optimum temperature and polymerization time was found to be 70 degrees C and 4 h, respectively. Increasing monome r concentration from 0.28 to 1.22M and initiator concentration from 1. 77 x 10(-3) to 4.20 x 10(-3)M enhanced the percent grafting. The effec ts of monomer and initiator diffusion on PET films were also studied. The overall activation energy for grafting was calculated as 11.5 kcal /mol. Further changes in properties of PET films such as water-absorpt ion capacity and intrinsic viscosity mere determined. The grafted film s were characterized with FTIR and scanning electron microscopy (SEM). (C) 1997 John Wiley & Sons, Inc.