CIESC Journal

• 材料科学与工程 • 上一篇    下一篇

聚乳酸固相缩聚模型

钱刚;王海娟;周兴贵;袁渭康   

  1. 华东理工大学联合化学反应工程研究所,上海 200237

  • 出版日期:2005-01-25 发布日期:2005-01-25

Modeling of solid-state polymerization of PLLA

QIAN Gang;WANG Haijuan;ZHOU Xinggui;YUAN Weikang

  

  • Online:2005-01-25 Published:2005-01-25

摘要: 提出了聚乳酸固相缩聚的反应-扩散综合模型,该模型中考虑了可逆酯化反应和热降解反应.并由实验数据拟合得到了不同温度下各反应的速率常数以及水的扩散系数,进而得到它们的活化能;模拟了不同因素对固相缩聚过程的影响.研究表明在较低的温度下,热降解反应的影响较小,可以忽略;而在较高温度下,其影响显著.水的扩散速率对聚乳酸分子量的增长影响很大;小粒径颗粒有利于制备高分子量聚乳酸.

Abstract: A reaction and diffusion model is developed for the process of solid-state polymerization(SSP) to increase the molecular mass of poly(L-lactic acid)(PLLA).Three reactions are considered: forward and backward polycondensation reactions and thermal degradation reaction.The rate constants of these reactions and diffusivity of water are obtained by fitting the model to experimental data,on the basis of which the activation energies were estimated.Degradation is found to be insignificant at low reaction temperature, while at high reaction temperature it becomes important and cannot be neglected.The diffusivity of water has an important effect on molecular mass growth.Small particle is favorable to obtain a high molecular mass product.