Blending of poly( l -lactide) and poly( d -lactide) (PLLA, PDLA) results in the formation of poly(lactide) stereocomplex crystallites (SC). For the preparation method, numerous reports employed solution mixing and stirring to receive a product with uniform performance. However, the effect of stirring time during solution mixing on the subsequent crystallization behavior did not clear yet, and which is important for solution crystallization, casting and spinning. In this paper, linear PLLA and PDLA with various molecular weights were synthesized. The PLLA and PDLA solutions were mixed together and stirred for different times before casting. Results revealed that the structures of PLA SC and homochiral crystallites (HC) did not vary with change in the stirring time. More amount of content of SC with uniform structure and less amount of content of HC were produced in the specimens stirred for longer time. When the specimens crystallized either from the melt or from the melt-quenching, less amount of content of crystallites (total crystallinity of SC and HC) was produced and the melting temperature of SC and HC depressed in the specimens that were stirred for longer time. With the increase in molecular weights, the effect of stirring time on the crystallization behaviors declined. This investigation provides a route to tailor the crystallization behavior of PLLA/PDLA specimens.

中文翻译：

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聚（l-丙交酯）/聚（d-丙交酯）共混物的结晶行为：溶液混合过程中搅拌时间的影响

聚（l-丙交酯）和聚（d-丙交酯）（PLLA、PDLA）的混合导致聚（丙交酯）立体络合物微晶（SC）的形成。对于制备方法，许多报道采用溶液混合和搅拌来获得性能均匀的产品。然而，溶液混合过程中搅拌时间对后续结晶行为的影响尚不清楚，这对于溶液结晶、浇铸和纺丝很重要。本文合成了不同分子量的线性PLLA和PDLA。在浇铸前将 PLLA 和 PDLA 溶液混合在一起并搅拌不同的时间。结果表明，PLA SC 和同手性微晶 (HC) 的结构不随搅拌时间的变化而变化。在搅拌时间较长的试样中，产生较多的结构均匀的SC含量和较少的HC含量。当样品从熔体中结晶或从熔体淬火中结晶时，产生的微晶含量（SC 和 HC 的总结晶度）较少，并且搅拌时间较长的样品中 SC 和 HC 的熔化温度降低。随着分子量的增加，搅拌时间对结晶行为的影响下降。该研究为定制 PLLA/PDLA 样品的结晶行为提供了一条途径。在搅拌较长时间的样品中，产生较少量的微晶含量（SC 和 HC 的总结晶度）并且 SC 和 HC 的熔化温度降低。随着分子量的增加，搅拌时间对结晶行为的影响下降。该研究为定制 PLLA/PDLA 样品的结晶行为提供了一条途径。在搅拌较长时间的样品中，产生较少量的微晶含量（SC 和 HC 的总结晶度）并且 SC 和 HC 的熔化温度降低。随着分子量的增加，搅拌时间对结晶行为的影响下降。该研究为定制 PLLA/PDLA 样品的结晶行为提供了一条途径。