High Performance Polylactide Toughened by Supertough Polyester Thermoplastic Elastomers:Properties and Mechanism  

作　　者：FENG Songyang ZHAO Wuchao HE Jianghua ZHANG Yuetao 

机构地区：[1]State Key Laboratory of Supramolecular Structure and Materials,College of Chemistry,Jilin University,Changchun 130012,P.R.China

出　　处：《Chemical Research in Chinese Universities》2023年第5期750-756,共7页高等学校化学研究（英文版）

基　　金：This work was supported by the National Key Research and Development Program of China(No.2022YFB3704900);the National Natural Science Foundation of China(Nos.22225104,22071077,21871107,21975102);the China Postdoctoral Science Foundation(Nos.2022TQ0115,2022M711297).

摘　　要：It is a challenge to develop a biodegradable toughener to toughen polylactic acid(PLA)with both high strength and high toughness,since toughness and strength are mutually exclusive.Here,a series of supertough polyester thermoplastic elastomers(TPEs),poly(L/D-lactide)-b-poly(ε-caprolactone-co-δ-valerolactone)-b-poly(L/D-lactide)s(PLLA-PCVL-PLLA,L-TPEs or PDLA-PCVL-PDLA,D-TPEs),were prepared and blended with a PLLA matrix to toughen PLLA.The mechanical properties of PLLA could be regulated in a wide range by changing blending ratios and TPE structures.For PLLA blends toughened by L-TPEs,the highest elongation at break is up to 425%with the tensile strength of 33.1 MPa and the toughness of 104 MJ/m3.By the stereocomplex crystallization of PLA(sc-PLA),the tensile strength of the PLLA/D-TPE blends further increased to 41.8 MPa with a similar elongation at break(418%)and the toughness up to 128 MJ/m3.The detailed characterizations revealed a toughening mechanism:(I)the added soft segments increased the ductility of the PLLA matrix,(II)the PLLA segments of L-TPEs increased the compatibility between TPEs and PLLA matrix,and(III)the formation of sc-PLA between the PDLA segments in D-TPE and PLLA provided higher tensile strength by enhancing the strength of the crystal skeleton.The toughened PLA using TPEs can maintain original non-toxic and degradable properties,and be applied potentially in surgical sutures,and 3D-printed scaffolds.

关 键 词：Super-tough polyester elastomer Poly-L-lactic acid toughening Biodegradable polymer Stereocomplex crystallization 

分 类 号：TQ3[化学工程]