LIPASE-CATALYZED LINEAR ALIPHATIC POLYESTER SYNTHESIS IN ORGANIC-SOLVENT

Enzymatic polymerization of bis(2,2,2-trifluoroethyl) sebacate and ali phatic diols was investigated with the purpose of obtaining a polyeste r of as high as possible average molecular weight. The reaction was ca rried out at 37 degrees C, and vacuum was applied to shift the equilib rium forward by removal of the 2,2,2-trifluoroethanol formed. The resu lts showed that the elimination of alcohol formed was critical for a h igh degree of polymerization. Among the four lipases studied, Mucor mi ehei lipase was the best biocatalyst for polytransesterification and d iphenyl ether was the best solvent for the polymerization of bis(2,2,2 -trifluoroethyl) sebacate with 1,4-butanediol. The highest average mol ecular weight ((M) over bar(W)) of 46,400 g mol(-1) (degree of polymer ization = 184) was obtained when 0.51 M (187 g l(-1)) bis(2,2,2-triflu oroethyl) sebacate was polymerized with 0.51 M (46 g l(-1)) 1,4-butane diol in diphenyl ether for 168 h (7 days) with 36.5% M. miehei lipase powder.