STUDY OF THE STRUCTURE OF POLYETHYLENE AND POLY(TETRAFLUOROETHYLENE) RADIATION GRAFTED ION-EXCHANGE COPOLYMERS

Cation- and anion-exchange copolymers were synthesized by radiation in duced copolymerization of acrylic acid and 4-vinylpyridine onto polyet hylene and poly(tetrafluoroethylene) (PTFE) films. The grafting was ca rried out by the direct method of single or multiple (discrete) irradi ation by gamma-rays from a Co-60 source. The grafting degree was from 10 to 121% for polyethylene and from 2.5 to 50% for poly(tetrafluoroet hylene), depending on the irradiation dose (1-50 kGy). The calorimetri c curves of the copolymers synthesized showed a glass transition tempe rature (T-g) at 333 +/- 10 K. The enthalpies of melting and crystalliz ation decreased with increasing degree of grafting. The data from wide angle X-ray analysis indicated an increase of the amorphous part with degree of grafting. At lower grafting degrees of poly(acrylic acid) a nd poly(4-vinylpyridine) (up to 15%) onto PTFE matrix, the size of the crystallites was found to increase. The penetration of the grafted fu nctional monomer leads to partial deorientation of the initial LDPE fi lm.