中文摘要：

在采用红外光谱仪和X衍射仪了解新鲜乳酸锌和回收乳酸锌的化学结构和晶型的基础上，比较了新鲜乳酸锌和回收乳酸锌对丙交酯粗产率和丙交酯含酸率的影响，并考察了催化剂用量、脱结合水时间的影响。结果表明，新鲜乳酸锌和回收乳酸锌的化学结构相同，都是由正方晶、斜方晶和单斜晶组成的混晶结构，但各晶型的含量不同。回收乳酸锌的催化活性与新鲜乳酸锌相当，丙交酯产率分别为75．7％、72．1％。这表明乳酸锌是一种价廉、催化效率高且可回收使用的丙交酯催化剂，这对于工业化生产中降低生产成本有一定指导意义。

英文摘要：

The catalytic efficiency of zinc lactate as a catalyst to prepare lactide from lactic acid was evaluated compared ose commonly used catalysts including zinc oxide, solid superacid and stannous octate, which indicated a much catalytic efficiency of zinc lactate than others. After mensurating the chemical structure and the crystal form of zinc lactate and recycled zinc lactate, the effects of catalyst and oligomerization time on the yield of crude lactide and the content of lactic acid in lactide product were studied. As a result, both zinc lactate and recycled zinc lactate showed same chemical structure and were comprised three crystal forms. Using zinc lactate and recycling zinc lactate as a cata- lyst, the yield of lactide were 75.7% ,72.1% , respectively. These indicate that zinc lactate is a kind of cheap, available, recyclable catalyst, which is significant in the industrial production of lactide.