交联聚乳酸在静态和拉伸应力下的结晶行为研究

Study of Crystallization Behavior of Cross-linked PLA under Quiescent and Tensile-stress Conditions

研究不同凝胶含量聚乳酸(PLA)的结晶行为,发现随着凝胶含量的增加,聚乳酸的结晶能力下降。在65℃拉伸作用下,PLA交联网络不能运动,未交联的PLA表现出更好的拉伸取向和诱导结晶能力,拉伸性能更好。在105℃拉伸作用下,未交联PLA容易滑移解缠,不利于拉伸取向和结晶,而PLA交联网络更利于沿拉伸方向取向排列成为结晶前驱体并诱导结晶,表现出更好的应变硬化,断裂强度提高。

The crystallization behavior of PLA with different gel content was studied. The crystallization of PLA was decreased with increasing the gel content. When stretched at 65 22, the cross-linked network of PLA could hardly move, and the PLA sample without cross-linking had high orientation and crystallization capacity under drawing, resulting in better tensile properties. While stretched at 105 ℃ the PLA sample without cross-linking slipped and disentangled easily, which restrained the orientation and crystallization of PLA. The cross-linked PLA chains aligned along the tensile direction to form the crystal precursor and induce crystallization under stretched at 105 ℃. Thus it showed higher obvious strain-hardening and higher break strength.