Chemo-enzymatic synthesis and characterization of graft copolymers from lignin and acrylic compounds

Chemo-enzymatic initiation of graft copolymerization of acrylic compounds o nto different technical lignosulfonates (LS) was compared to a Fenton-like system (ferrous ion, t-BHP). The enzyme tested was a phenoloxidase laccase (EC 1.10.3.2) from the white rot basidomycete Trametes versicolor. Most app lied lignins were successfully grafted, resulting in a polymer yield of mor e than 90%. The effect of initiator concentration and the lignin/monomer ra tio on the yield and (M) over bar(w) of enzymatically grafted polymers were studied. The homopolymer proportion in the enzymatically produced grafts o f Ca-LS and acrylic acid was 5 to 6x lower than those initiated by the Fent on-like reagent; no such differences were observed for Na-LS. (C) 2000 Else vier Science Inc. All rights reserved.