Impact-Resistant PLLA/PBAT Composites Based on Novel Biobased Reactive Microcross-Linked PBAT
Yichen Xu, Xin Meng, Xinze You, Wang Jiang, Pu Du, Li Jiao, Chenyang Li, Bo Bao, Zhong Xin
Abstract
Due to the differences in molecular structure, Poly(L-lactide) (PLLA) and Poly(butylene adipate- co -terephthalate) (PBAT) are inherently immiscible in the melt processing, resulting in limited mechanical properties of the PLLA/PBAT blends. Herein, a novel biobased microcross-linked PBAT has been prepared through dynamic vulcanization in the presence of dicumyl peroxide (DCP) and cardanol glycidyl ether (CGE). The rheological behavior showed that the modified PBAT exhibited high complex viscosity and storage modulus in comparison to virgin PBAT due to the formation of a cross-linking structure. When the contents of DCP and CGE were, respectively, 1.0 and 2.0 wt % compared to PBAT, the cross-linking degree of the modified PBAT named B/1.0D/2.0C reached the maximum of 37.1%. At the aid of this modified PBAT, the notched impact strength and elongation at break of the blend of PLLA and the modified PBAT reached 10.0 kJ/m 2 and 265.4%, respectively, about 2.0 and 1.8 times that of pristine L/B blends. The toughening effect was attributed to the enhanced melt viscosity of the microcross-linked PBAT and the improved interfacial interaction between PLLA and PBAT. The molecular dynamic simulation results further confirmed that the microcross-linked PBAT had better miscibility and toughening effect for PLLA compared to virgin PBAT. Thus, this work paved a new way for the preparation of fully biodegradable impact-resistant PLLA-based composites.