Patent ID: 6359102
Filing Date: 2002-03-19
Classification: C08G

Abstract:
In a biphasic polymerization process for providing an amino acid derived polymer, comprising the steps of:admixing an aqueous solution comprising a first monomer with a water-immiscible organic solvent; adding to the admixture a catalyst selected from the group consisting of tertiary amine, quaternary amine and phosphonium catalysts, an acid-forming co-monomer for said first monomer and an acid scavenger; and recovering the resulting amino acid derived polymer, the improvement comprising:providing said aqueous solution at a pH from about six to about eight, and adding to said admixture said acid-forming co-monomer and said acid scavenger at relative rates effective to maintain said pH of said admixture in a range from about six to about eight, to thereby prevent said first monomer from hydrolyzing to form an acid prior to polymerization, wherein said resulting amino acid derived polymer is hydrolytically unstable at physiological conditions.