Study of the structure of polyethylene and poly(tetrafluoroethylene) radiation grafted ion-exchange copolymers

✍ Scribed by Sevdalina Turmanova; Antoaneta Dimitrova; George Kostov; Emanuel Nedkov

• Publisher: John Wiley and Sons
• Year: 1996
• Tongue: English
• Weight: 407 KB
• Volume: 197
• Category: Article
• ISSN: 1022-1352
• DOI: 10.1002/macp.1996.021970929

✦ Synopsis

Abstract

Cation‐ and anion‐exchange copolymers were synthesized by radiation induced copolymerization of acrylic acid and 4‐vinylpyridine onto polyethylene and poly(tetrafluoroethylene) (PTFE) films. The grafting was carried out by the direct method of single or multiple (discrete) irradiation by γ‐rays from a ^60^Co source. The grafting degree was from 10 to 121% for polyethylene and from 2.5 to 50% for poly(tetrafluoroethylene), depending on the irradiation dose (1–50 kGy). The calorimetric curves of the copolymers synthesized showed a glass transition temperature (T~g~) at 333 ± 10 K. The enthalpies of melting and crystallization 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) and poly(4‐vinylpyridine) (up to 15%) onto PTFE matrix, the size of the crystallites was found to increase. The penetration of the grafted functional monomer leads to partial deorientation of the initial LDPE film.