改善基体结晶和界面强度是实现聚乳酸/弹性体共混物高耐热和超韧化的关键。添加有机成核剂和反应性增容是目前促进基体结晶、提高界面强度最为有效的方法，然而，反应增容在增强界面的同时容易引起成核剂成核效率的大幅降低。本项目受到由右旋聚乳酸（PDLA）和左旋聚乳酸（PLLA）形成的立构复合晶体（Sc-PLA）可充当PLLA高效成核剂的启发，从PDLA接枝改性弹性体入手，创造性地提出利用熔融共混法在PLLA/弹性体共混物界面上原位构筑Sc-PLA的策略来同步实现界面增强与基体结晶改性的双重功能。研究由弹性体中PDLA的链段长度、含量以及加工条件控制的Sc-PLA微观结构对界面强度和基体结晶行为影响的科学规律，通过断裂行为分析，揭示界面和基体在增韧过程中的协同作用机制，结合耐热性能评价，建立基于Sc-PLA调控的界面强度和基体结晶制备耐热超韧共混物的机理模型，为高性能PLLA材料的定构加工提供新的思路。

The key to achieving superior toughness and high heat resistance in polylactide/elastomer blends is to improve matrix crystallization and interfacial adhesion. Adding organic nucleating agent (NA) and reactive blending are the most effective method to accelerate matrix crystallization and enhance interface adhesion strength, respectively. However, the use of reactive compatibilization method for improving the interfacial adhesion can easily lead to a significant decrease in nucleation efficiency of NA on matrix. In this project, inspired by the fact that poly(D-lactide）(PDLA) and poly(L-lactide）(PLLA) can form stereocomplex (Sc-PLA) that could act as NA for PLLA crystallization, we propose a creative strategy to construct Sc-PLA with dual functionality as both interfacial adhesion enhancer and matrix crystallization accelerator at the interface by melt-blending of PLLA and elastomers grafted with PDLA. The microstructure of Sc-PLA, which dominates the interfacial adhesion and the matrix crystallization, will be tailored by controlling the PDLA segmental length in the grafted copolymers, the amount of PDLA in the elastomers, and the processing conditions. By analyzing the impact fracture behaviors and heat resistance, a theory framework for fabricating heat-resistant and super-tough blends via tailoring interfacial adhesion strength and matrix crystallization assisted by stereocomplex will be set up on the basis of the complete understanding on the synergistic roles of matrix crystallization and interfacial strength in the toughening of PLLA with elastomers. After completing this project, it is expected to develop a new route for direct structuring high-performance PLLA products.