A detailed study of the enzyme-catalyzed preparation of polymers will be undertaken in two general areas: (1) exploration of the factors which determine the molecular weight of (AA-BB)x polyesters formed by hydrolase-catalyzed transesterification in organic solvents; and (2) exploration of the scope and limitations of enzyme-catalyzed polymerization method. In examining the factors affecting molecular weight, variations will be made relative to a standard polycondensation, the porcine pancreatic lipase catalyzed reaction of bis(2,2,2- trichloroethyl) glutarate with 1,4-butanediol in anhydrous ether at combient temperature. Among the factors to be varied in a systematic fashion are the stoichiometry of the monomers, the concentratins, of the reactants and the catalyst in the solvent, the length of the monomers, the leaving group lost in the transesterification, the solvent, the reaction temperature, and the enzyme catalyst. The scope and limitations of enzyme-catalyzed polycondensations will be explored in five areas: (1) preparation of (AA-BB)x polymers form a variety of different diester (or diacid) and diol monomers and examination of the early intermediates formed during the process; (2) extension of the process to the formation of of (A-B)x polymer; (3) development of additional examples of optically active polymer formation using the method; (4) application of enzymes in the preparation of stereoregular monomers; (5) examination of the ability of enzymes to make polymers other than polyesters such as polyamides polycarbonates.
