丙交酯

The in situ graft copolymerization of starch with D, L-lactide was investigated.

研究了在聚乙二醇存在下，淀粉与丙交酯的原位熔融接枝反应。

It is reported that polylactide is the most promising fracture-fixing material which is degradable in the body.

文献报导聚丙交酯是最有希望的可体内降解的骨折固定材料。

The effects of dehydration temperature, ratio of dehydration, catalyst dosage, polymerization and depolymerization temperature on the yield of D, L-lactide were studied.

考察了制备过程中脱水温度、脱水率、催化剂量、聚合温度和解聚温度对丙交酯产率的影响。

When lactide was purified byethyl acetate for 4 times, it was pure enough to polymerize to be PLA.

以乙酸乙酯作为重结晶溶剂，当重结晶次数达到四次后，其纯度已达到丙交酯聚合的基本要求。

The orthogonal design method is adopted, by changing catalyst category, catalyst quantity, reaction time, reaction temperature, to select the optimum conditions for lactide synthesis.

实验采用正交设计方法，通过改变催化剂种类、催化剂用量、脱水时间、环化时间四个主要影响因素进行实验，根据实验结果选择最好的丙交酯制备的实验方案。

The synthesis, characterization and polymerization of a new cyclic 6-(N-isopropyl acylamine ethylidene)-ε-caprolactone were reported.

研究了官能团化新型己内酯单体的合成及其与丙交酯无规共聚物的降解性能。

Firstly, D,L-lactide was synthesized from D,L-lactic acid with zinc powder as catalyst,and glycolide from glycolic acid using Sb2O3 as catalyst.

首先以乳酸为原料，锌粉为催化剂合成了丙交酯；以乙醇酸为原料，三氧化二锑为催化剂合成了乙交酯。

The resulted D,L-lactide and glycolide were found to have ring structure by fourier transform infrared spectrometry and proton nuclear magnetic resonance(1H NMR) spectrometry.

通过傅立叶红外光谱和氢核磁谱(1H NMR)测试表明所合成的丙交酯和乙交酯具有环状结构。

Then two star-shaped oligomers with designed molecular weights 5000 g mol-1 and 10000 g mol-1, respectively, were synthesized from D, L-lactide and glycolide as raw materials and pentaerythritol as initiator under catalysis of dibutyltin oxide.

以合成的丙交酯和乙交酯为原料，季戊四醇为引发剂，氧化二丁基锡为催化剂合成出设计分子量为5000和10000两种预聚物。

The morphologies formed were characterized by SEM and DLS methods, and spherical particles with various sizes were observed.5. To obtain a amphiphilic dumbbell-shaped copolymer, we successfully synthesized dendritic-linear-dendritic triblock copolymers composed of linear polystyrene and poly dendrons.

树枝状共聚物最外层PSt-PNAS链段利用乙二胺和NAS活性酯的取代反应交联，同时，中间的聚丙交酯段被降解，得到纳米空心球，用SEM和DLS进行观测和表征。5。

For a big chunk of credit-card losses; the number of filings (and thus charge-off rates) would be rising again, whether

年美国个人破产法的一个改动使得破产登记急速下降，而后引起了信用卡大规模的亏损。

Eph. 4:23 And that you be renewed in the spirit of your mind

弗四23 而在你们心思的灵里得以更新