丙交酯

The effects of splitting temperature on optical purity of lactide were discussed.

以金属锌作催化剂制备丙交酯，研究了不同裂解温度对产物光学纯度的影响。

Theoretical studies on synthetic process of lactide were carried out with density functional theory and the geometries of compounds maybe to appear in reactive system were optimized.

采用密度泛函方法研究了丙交酯的合成过程，优化了合成过程中可能出现的化合物的几何构型，分析了各化合物的振动频率和偶极矩。

The key of indirect method is the preparation of intermediate lactide.

间接法合成PDLLA的关键在于中间体D，L-丙交酯的制备。

The results showed that, melting point of high yield lactide made in the lab reached 127℃ after three times of recrystallization, and the yield of lactide reached 57.2%.

结果表明：自制高收率丙交酯经过3次重结晶后，熔点可达到127℃，熔程在1℃以内，总产率为57.2%。

It was shown that high optical purity lactide and crystallization in polymerization led to higher molecular weight PLA using low-toxic zinc lactate as catalyst.

结果表明，合适的裂解温度有利于合成高光学纯度的丙交酯；在低毒乳酸锌的催化作用下，高光学纯度的单体以及聚合过程中的结晶都有利于制备高分子量聚乳酸。

Nitrogen was used as carrier gas and the area normalization method was applied to calculate the content of the crude lactide.

采用TP-5毛细管柱，以氢火焰离子化检测器检测，N2为载气，以校正面积归一化法计算粗品丙交酯中各组分的含量。

This review focused on the reasearch progress of polylactide synthesised either by direct polycondensation of lactic acid or ring-opening polymerization of lactide at home and aborad in recent years.

综述了近年来国内外聚乳酸直接合成法和丙交酯开环聚合法的研究进展，对聚乳酸改性方法进行了深入的总结和评述，并揭示了聚乳酸材料的研究开发前景。

As compared with the lactide ring-opening polymerization, the direct melting copolymerization of LA and CL is proved more practicable and simpler.

与丙交酯开环聚合二步法相比，LA与CL直接熔融共聚的合成工艺简单易行。

The reason why polylactide is a noncrystalline polymer, and its degradation relocity is big, which fulfils the biomedical requirement as a degradable material.

由于聚D，L丙交酯是非结晶聚合物，其降解速率大，可完全符合生物医学对降解材料的要求。

In this paper, not only the mechanism of thermal degradation of polylactide is introduced, but also the kinds of metal catalysts, their influence on L-lactide formation and racemization through thermal degradation of PLLA are referred.

本文介绍了聚乳酸热降解的反应机理，详细阐述了添加的金属催化剂的种类，及其催化PLLA热降解生成L-丙交酯及发生消旋化作用的机理。

The split between the two groups can hardly be papered over.

这两个团体间的分歧难以掩饰。

This approach not only encourages a greater number of responses, but minimizes the likelihood of stale groupthink.

这种做法不仅鼓励了更多的反应，而且减少跟风的可能性。