Abstract: Polylactic acid (PLA) has attracted great attention because of its biodegradability, excellent functional performance and wide application area. Two kinds of chemical synthetic methods of PLA, ring-opening polymerization of lactide (ROPL) and condensation polymerization of lactic acid (CPLA), are reviewed. High molecular weight PLA can be obtained with simple equipment by ROPL route, whereas high cost, complicated technique and long procedure are associated. Alternatively, CPLA route is favorable on the basis of abundant source of cheap raw material, high monomer conversion rate and simple synthetic technique. Meanwhile, the process of intermediate purification is not needed, which leads to low production cost. However, high molecular weight polymer cannot be obtained by this route. Currently, the important research area of PLA includes developing new synthetic technology to further reduce the manufacturing cost. It is imperative to make a breakthrough to find a simple and easy way to prepare PLA with high molecular weight.

Key words: polylactic acid(PLA), lactide, synthesis

摘要： 聚乳酸因可生物降解、性能优异、应用广泛而深受青睐。本文介绍了2种主要化学合成聚乳酸的方法：丙交酯开环聚合法和乳酸直接缩聚法。分析了这2种方法的优势和缺陷：丙交酯开环聚合法设备简单，可得到大分子量的聚乳酸，缺点是成本较高，整个工艺复杂，路线长；乳酸直接缩聚法原料乳酸来源充足，价格便宜，单体转化率较高，工艺简单，不需要经过中间体的纯化，因而成本较低，缺陷是较难得到高分子量的聚合物。文中指出积极开展聚乳酸的合成工艺研发、进一步降低生产成本是当前聚乳酸研究的重要课题，重点在于简单易行的高分子量聚乳酸合成工艺的突破。

关键词: 聚乳酸, 丙交酯, 合成