聚乙交酯的合成

Synthesis of polyglycollide

利用搅拌反应釜合成了聚乙交酯(PGA);应用红外光谱、核磁共振等对聚合物的结构进行了表征; 研究了PGA聚合过程中特性粘数、单体转化率、聚合物的热稳定性等的变化。结果表明:聚合物转化率和聚合物特性粘数的变化趋势相同,反应开始阶段变化较慢,随后加快,最后趋于平缓。聚合时间为105 min时, 聚合物的特性粘数达到最大为1．0 dL／g,单体的转化率为99．0％,随着特性粘数的增加,聚合物的热稳定性提高;PGA的流变性能受相对分子质量影响显著,没有反应完全的试样仍具有聚合活性。

Polyglycollide （PGA） was synthesized in a stirred reactor. The structure of the obtained polymer was characterized by infrared spectrum analysis and nuclear magnetic resonance spectroscopy. The changes in intrinsic viscosity, monomer conversion rate and thermal stability of the polymer were studied during the polymerization. The results showed that the conversion rate and the intrinsic viscosity had the same variation trend. Their variation was slow at first, then accelerated and finally moderated. The intrinsic viscosity and conversion rate were maximized as 1.0 dL/g and 99.0%, respectively, when the polymerization time was 105 min. The thermal stability was improved with increasing intrinsic viscosity. The rheological behavior of PGA was profoundly affected by relative molecular weight. The samples without reacting completely retained the activity of polymerization.