Patent ID: 7091011

Claim:
A process for synthesizing a highly branched copolyester product comprising the steps of: (a)contacting a 3-hydroxynitrile in an aqueous reaction mixture with an enzyme catalyst characterized by 1) nitrile hydratase and amidase activity of microbial cells selected from the group consisting of Acidovorax fecilis 72W (ATCC 55746), Comamonas testosteroni 22-1(ATCC PTA-1853), Comamonas testosteroni 5-MGAM-4D (ATCC 55744), Dietzia sp. ADL1 (ATCC PTA-1854), Syctalidium spp. 3LD-122P (ATCC PTA-1855), Rhodococcus sp. 25-1 (ATCC PTA-1856), and Pseudomonas putida 5B-MGN-2P (NRRL-B-18566); or 2) nitrilase activity of microbial cells selected from the group consisting of Acidovorax facilis 72-PF-15 (ATCC 55747), Acidovorax facilis 72-PF-17 (ATCC 55745), and Acidovorax facilis 72W (ATCC 55746), the Acidovorax facilis 72W (ATCC 55746) heat-treated to inactivate nitrite hydratase and amidase activities; whereby a linear 3-hydroxycarboxylic acid is produced; (b)contacting and heating a mixture of (1) at least one hyperbranching hydroxycarboxylic acid of the structure (R 2 O) n —R—[C(O)OR 1 ] m , wherein R is C 1-12 hydrocarbyl radical with n+m free valencies, R 1 is H, C 1-12 or hydroxyl substituted C 1-12 hydrocarbyl radical, R 2 is H or O(O)CR 3 , R 3 is H or C 1-12 hydrocarbyl radical, n+m is 3 or more, and provided that one of n and m is 1, (2) a linear 3-hydroxycarboxylic acid of the structure R 2 O—CR 4 R 5 CR 6 R 7 C(O)OR 1 produced in step (a), wherein R 4 R 5 R 6 R 7 is H or C 1-12 hydrocarbyl radical, and (3) an esterification catalyst; and (c)collecting the highly branched copolyester product of step (b).