Synthesis and bacterial degradation of an azopolymer

Azopolymers were synthesised with differing degrees of hydrophobicity, from 2-hydroxyethylmethacrylate (HEMA), styrene and 2,2'-dimethylacryloyloxyazo benzene as azo crosslinker. Bacterial degradation of the series of polymers was assessed using a purr culture of the colonic organism Enterococcus fae calis and rat caecal contents. Polymer degradation was determined in terms of weight loss on polymer coated glass beads and using scanning electron mi croscopy after incubation. Similar weight loss occurred on incubation of po lymers in both bacterial cultures and non-bacterial control. The presence o f styrene was found to decrease the amount of weight loss. The polymer surf aces showed microscopic cracks and holes after incubation, again, this phen omenon was less pronounced with increasing styrene content. As there was no increase in polymer degradation in the presence of azo reducing microorgan isms, the results of this study suggest that these polymers are degraded by mechanisms other than azo reduction. (C) 2000 Published by Elsevier Scienc e B.V. All rights reserved.