Plasticization of amorphous polylactide shifts the glass transition and extends its temperature range of crystallization to lower temperatures. In this work, we focus on how low−temperature crystallization impacts the mobility of the amorphous phase. Plasticizer accumulates in the amorphous phase because it is excluded from the growing crystal. The formation of rigid amorphous fraction is favored by the low crystallization temperature. It reaches values up to 50% in plasticized polylactide. The increase in the content of rigid amorphous fraction coincides with both the increase of free volume quantified by positron annihilation lifetime spectroscopy, and the decrease in the cooperativity length obtained from the temperature fluctuation approach. The drop of cooperativity is interpreted in terms of mobility gradient due to the amorphous rigidification.

非晶态聚丙交酯的增塑可改变玻璃化转变，并将其结晶温度范围扩展至更低的温度。在这项工作中，我们专注于低温结晶如何影响非晶相的迁移率。增塑剂在非晶相中积累，因为它已从生长的晶体中排除了。较低的结晶温度有利于形成刚性无定形部分。它在增塑聚丙交酯中的含量高达50％。刚性无定形部分含量的增加与通过正电子an没寿命光谱法定量的自由体积的增加以及通过温度波动方法获得的协同长度的降低都相符。