Title

Photocrosslinking of Poly(ethylene Terephthalate) Copolymers Containing Photoreactive Comonomers

Document Type

Article

Publication Date

8-23-2005

Department

Polymers and High Performance Materials

Abstract

Poly(ethylene terephthalate) (PET) copolymers containing 4,4'-, 3,5-, and 2,4-benzophenone dicarboxylate chromophores have been synthesized by transesterification of PET with benzophenone 4,4'-dicarboxylic acid (4,4-BDA), dimethyl benzophenone 4,4'-dicarboxylate (4,4'-BDE), dimethyl benzophenone 3,5-dicarboxylate (3,5-BDE) and dimethyl benzophenone 2,4-dicarboxylate (2,4-BDE). The benzophenone segments in the backbone induce photocrosslinking upon UV irradiation in the solid state most probably by a hydrogen atom abstraction mechanism. The crosslinking rate depends upon the concentration and the structure of chromophores as evidenced by gel content measurements. The photocrosslinking efficiency of 4,4'-benzophenone dicarboxylate containing polymers is higher than for 2,4- or 3,5-benzophenone dicarboxylate containing polymers. Photocrosslinked PET copolymers show increased glass transition temperatures and broadening of melting transitions. (c) 2005 Elsevier Ltd. All rights reserved.

Publication Title

Polymer

Volume

46

Issue

18

First Page

6897

Last Page

6909