Synthesis and degradation of end-group-functionalized polylactide

Three kinds of OH-terminated polylactides were synthesized by the ring open ing polymerization of lactide, with an alcohol such as dodecanol, glycerol, or pentaerythritol, in the presence of stannous octoate. Moreover, Cl-, NH 2-, and COOH-terminated polylactides were synthesized from OH-terminated po lylactides. The end groups of the polylactides were identified by H-1 NMR a nd C-13 NMR. According to thermal analysis, the cold crystallization temper atures of Cl-, NH2-, and COOH-terminated polylactides were higher than thos e of OH-terminated polylactides. The thermal stability of OH-terminated pol ylactides was poor, whereas NH2- and Cl-terminated polylactides were more r esistant to thermal degradation. In a hydrolysis degradation test, the mass and molecular weight loss of COOH-terminated polylactides were high, where as those of Cl- and NH2-terminated polylactides were much lower. These end- group effects were increased with an increasing number of chain arms. (C) 2 001 John Wiley & Sons, Inc.