Synthesis and characterization of degradable copoly(ester-amide)s:: Poly(trans-4-hydroxy-L-proline-co-ε-caprolactam)

Novel copolyesteramides were synthesized by reacting trans-4-hydroxy-N-benzyloxycarbonyl-L-proline (N-CBz-Hpr) with epsilon-caprolactam (CLM) in the presence of stannous octoate [Sn(II) Oct.] as a catalyst. Various techniques, including H-1-NMR, IR, DSC, and viscosity, were used to elucidate structural characteristics and thermal properties of the resulting copolymers, Data showed that the optimal reaction condition for the synthesis of the copolymers was obtained by using 3 wt% Sn(II) Oct, at 170degreesC for 24 h. The DSC analysis demonstrated amorphous structure for most of the copolymers. The glass-transition temperature of the copolymers shifts to a higher temperature with increasing Hpr/CLM molar ratio. In vitro degradation of these poly(N-CBz-Hpr-co-CLM)s was evaluated by weight loss measurements. (C) 2002 Wiley Periodicals, Inc.