The radiation chemistry of the copolymer of tetrafluoroethylene with 2,2-bis(trifluoromethyl)-4,5-difluoro-1,3-dioxole

The radiation chemistry of the copolymer of tetrafluoroethylene and 2,2-bis (trifluoromethyl)-4,5-difluoro-1,3-dioxole (Teflon AF(R)) was investigated using gamma-irradiation under vacuum. Two types of resin were studied which differed in dioxole content; AF1600 65 mol% dioxole and AF2400 87 mol% dio xole. The cyclic fluoroplastic was found to undergo predominant main chain scission upon radiolysis, both above and below the glass transition tempera ture, which was characterised by a decrease in the glass transition tempera ture. FTIR analysis showed the formation of new carboxylate end groups as w ell as terminal unsaturation. Both CF . and CF2., radicals were identified using Electron Spin Resonance upon gamma-radiolysis and subsequent thermal annealing. The G-value for radical production at 77 K, G(R), was 1.6 for bo th resins. (C) 1998 Elsevier Science Ltd. All rights reserved.