Study on Solubility of Copoly (L-lactic acid/ glycolic acid) by Direct Melt Polycondensation

摘要

A two steps direct copolymerisation process of L-lactic acid(L-LA)/glycilic acid(GA) was developed. The first step is to produce oligomer of L-LA/GA and then the oligomer was polymerized with binary catalyst tin chloride dihydrate/p-toluenesulfonic acid. In this way, the copoly(L-LA/GA) (PLGA) without any organic solvent was synthesized directly. The solubility in chloroform of PLGA were studied by nuclear magnetic resonance (NMR). The results show that the solubility of PLGA in chloroform decreases with the increase of the average lengths of the glycolic acid units (LG).