LIPASE-CATALYZED LINEAR ALIPHATIC POLYESTER SYNTHESIS IN ORGANIC-SOLVENT

Enzymatic polymerization of bis(2,2,2-trifluoroethyl) sebacate and aliphatic diols was investigated with the purpose of obtaining a polyester of as high as possible average molecular weight. The reaction was carried out at 37 degrees C, and vacuum was applied to shift the equilibrium forward by removal of the 2,2,2-trifluoroethanol formed. The results showed that the elimination of alcohol formed was critical for a high degree of polymerization. Among the four lipases studied, Mucor miehei lipase was the best biocatalyst for polytransesterification and diphenyl ether was the best solvent for the polymerization of bis(2,2,2-trifluoroethyl) sebacate with 1,4-butanediol. The highest average molecular weight ((M) over bar(W)) of 46,400 g mol(-1) (degree of polymerization = 184) was obtained when 0.51 M (187 g l(-1)) bis(2,2,2-trifluoroethyl) sebacate was polymerized with 0.51 M (46 g l(-1)) 1,4-butanediol in diphenyl ether for 168 h (7 days) with 36.5% M. miehei lipase powder.