Degradation of acrylic copolymers by Fenton's reagent

The degradation of different copolymers of acrylamide and acrylic acid by Fenton's reagent was studied. The polymers tested were either homopolymers or copolymers containing lignin sulfonate, guaiacol or 3,4-dihydroxylbenzoic acid, respectively. Acrylamide copolymers (PAAm) were degraded faster than polymers of acrylic acid (PAA). Among the PAAm, the copolymers of lignin sulfonate and guaiacol were degraded at a significantly higher rate than the corresponding homopolymer, whereas among the PAA, the rate of degradation was highest with copolymers of guaiacol and 3,4-dihydroxylbenzoic acid. The decrease of H2O2, i.e. the rate of hydroxyl radical production in the presence of a certain polymer, did not correlate with the rate of its degradation. It was concluded that the incorporation of lignin and certain phenolic compounds into an acrylic chain may accelerate the decay of these polymers by wood decaying fungi, which reportedly produce hydroxyl radicals extra-cellularly, and through the use of advanced oxidation systems applied in sewage cleaning. (C) 2001 Elsevier Science Ltd. All rights reserved.