Department of Materials Chemistry, Graduate School of Engineering, Kyoto University, Kyoto, 606-8501, Japan
Abstract:
The lipase-catalyzed synthesis and curing of polyesters that possess an unsaturated fatty acid moiety in the side chain is described. Lipase-catalyzed polymerization of divinyl sebacate and glycerol in the presence of unsaturated fatty acids produced a crosslinkable polyester possessing the unsaturated group. Candida antarctica lipase showed high catalytic activity for their synthesis. Effects of reaction parameters, such as enzyme amount, temperature, and feed ratio of substrates, have been systematically investigated. The polymerization under reduced pressure improved the polymer yield and molecular weight. Divinyl adipate was also enzymatically polymerized with glycerol and linoleic acid to give the crosslinkable polyester. The polymer obtained using linoleic or linolenic acid, was cured using a cobalt naphthenate catalyst or thermal treatment to give a crosslinked, transparent, polymeric film with a high-gloss surface. The cured film was characterized by pencil-scratch hardness testing and FT-IR spectroscopy. The biodegradability of the obtained film was evaluated by biochemical oxygen demand (BOD) measurement in an activated sludge.
