Fully Bio-Based and Supertough PLA Blends via a Novel Interlocking Strategy Combining Strong Dipolar Interactions and Stereocomplexation
Xiangjian Chen, Chuanxi Li, Yingli Ding, Yang Li, Jinshan Li, Liming Sun, Jie Wei, Xiaohui Wei, Hao Wang, Kunyu Zhang, Li Pan, Yue‐Sheng Li
Abstract
Optimizing interfacial compatibility is one of the core issues for constructing high-performance green poly(lactic acid) (PLA) blends. Herein, we prepared a poly(epichlorohydrin)-b-poly(d-lactic acid) (PECH-b-PDLA) diblock copolymer as an efficient compatibilizer for poly(l-lactic acid)/poly(epichlorohydrin) (PLLA/CHR) blends. The PECH-b-PDLA enabled the blends to form unique interlocks among the chains through combining the strong dipolar interaction and PLLA/PDLA stereocomplexation (SC). This strategy endows the PLLA/CHR blend with a unique “co-continuous” structure composed of CHR particles as the core and a bilayer shell formed by the PECH entanglement layer with strong dipolar interaction and a rigid SC thin layer. Physical properties of the blends were remarkably improved by a co-continuous structure with enhanced interfacial adhesion between phases. The optimum formulation showed unprecedented balanced mechanical properties: a nonbroken sample with an impact strength of 106.7 kJ/m2 and a high elongation at break of up to 467.2%; both were about 40 times those of pure PLLA. The interlocking mechanism through strong dipolar interaction and SC provides a broadly applicable and facile strategy to achieve PLA materials with superior properties for expanded industrial application.