Enantiomeric stereo diblock poly(lactide) polymers of crystalline poly(l-lactide) or poly(d-lactide) with amorphous poly(dl-lactide) (PLLA-b-PDLLA and PDLA-b-PDLLA, respectively) were synthesized to have different molecular weights of crystalline block but similar overall molecular weights and the effects of fraction or molecular weight of crystalline block on the crystallization behavior, structure, morphology, and thermal properties of PLLA-b-PDLLA/PDLA-b-PDLLA blends were investigated for the first time. In the cases of isothermal crystallization from the melt, heating after melt-quenching, and solvent evaporation, PLLA-b-PDLLA/PDLA-b-PDLLA blends were crystallizable for crystalline block fraction down to 21.5 %, whereas in the case of cooling from the melt, PLLA-b-PDLLA/PDLA-b-PDLLA blends were crystallizable only for crystalline block fraction down to 46.1 %. Interestingly, the incorporated long amorphous PDLLA blocks facilitated exclusive SC crystallization in PLLA-b-PDLLA/PDLA-b-PDLLA blends with the crystalline block fractions of 46.1 and 21.5 %. As with the results reported for unblended PLLA-b-PDLLA, the transition crystallization temperature from α-form to δ-form decreased with decreasing crystalline block fraction. The melting temperatures of SC crystallites and homo-crystallites, radial growth rate of spherulites, and total crystallization rate decreased with a decrease in crystalline block fraction. For T_c range wherein only SC crystallites were formed, only one regime was observed irrespective of crystalline block fraction and Avrami exponent was not significantly affected by the presence of amorphous PDLLA block and T_c. The present study revealed that the incorporation of PDLLA block into PLLA and PDLA can be effectively utilized for enhancement of SC crystallization during solvent evaporation, cooling and isothermal crystallization from the melt.

合成了结晶聚（l-丙交酯）或聚（d-丙交酯）与无定形聚（dl-丙交酯）的对映体立体二嵌段聚（丙交酯）聚合物（分别为PLLA- b- PDLLA和PDLA- b- PDLLA）研究了不同分子量的晶体嵌段但总分子量相似以及晶体嵌段的分数或分子量对PLLA- b- PDLLA / PDLA- b- PDLLA共混物的结晶行为，结构，形态和热性能的影响第一次。从熔体中等温结晶，熔体淬火后加热和溶剂蒸发的情况下，PLLA- b-PDLLA / PDLA- b -PDLLA共混物的结晶块分数可降低至21.5％，而在从熔体冷却的情况下，PLLA- b -PDLLA / PDLA- b -PDLLA共混物仅可用于结晶块分数降低的结晶至46.1％。有趣的是，掺入的长无定形PDLLA嵌段促进了PLLA- b- PDLLA / PDLA- b- PDLLA共混物中的独家SC结晶，其中结晶嵌段分数为46.1％和21.5％。与报告的未混合PLLA- b结果相同-PDLLA，从α-型到δ-型的转变结晶温度随着结晶嵌段分数的降低而降低。SC晶体和均晶体的熔融温度，球晶的径向生长速率和总结晶速率随着晶体嵌段分数的降低而降低。对于仅形成SC微晶的T _c范围，仅观察到一种状态，而与晶体嵌段分数无关，并且无定形PDLLA嵌段和T _c的存在并不显着影响Avrami指数。本研究表明，将PDLLA嵌段掺入PLLA和PDLA中可有效地用于增强溶剂从熔体中蒸发，冷却和等温结晶过程中的SC结晶。