Stereocompfexed Poiy(iactide) Composites toward Engineering Plastics with Superior Toughness, Heat Resistance and Anti-hydrolysis  

作　　者：Bao-Gou Wu WeiJun Yang De-Yu Niu WeiFu Pong Ming-Qing Chen Tian-Xi Liu Ming-Liang Du Pi-Ming Ma 

机构地区：[1]The Key Laboratoryof Synthetic and Biogial Colloids,Ministyof Education,liangnan University,Wuxi214122 China

出　　处：《Chinese Journal of Polymer Science》2020年第10期1107-1116,I0006,共11页高分子科学（英文版）

基　　金：This work was financially supported by the National Natural Science Foundation of China(Nos.51873082 and 51903106);Fundamental Research Funds for the Central Universities(No.JUSRP11928).

摘　　要：Polyl(lactide),PLA,suffers from bitleness and low heat deflection temperature(HDT),which limits its application as an engineering plastic.In this work,poly(L-lactide)/poly(D-lactide)/ethylene-vinyl acetate glycidyl methacrylate random copolymer(PLLA/PDL A/EVM-GMA=1/1/x)composites were prepared by melt blending,and the in situ formed EVM-g PLA copolymers improved the compatibility between PLA and EVM-GMA.Subsequently,the blends were subjected to a two-step annealing process during compression molding,i.e.first annealing at 120℃ to rapidly form a certain amount of stereocomplex(sc)crystallites as nucleation sites,and then annealing at 200℃ to guide the formation of new sccrystallites.Both differential scanning calorimetry(DSC)and wide angle X-ray dffrction(WAXD)measurements confirmed the formation of highly stereocomplexed PLA products.Mechanical results showed that the PLLA/PDLA blend with 20 wt%of EVM-GMA had a notched impact strength up to 65 kJ/m2 and an elongation at break of 48%,while maintaining a tensile strength of 40 MPa.Meanwhile,dynamic mechanical analysis(DMA)and heat deflection tests showed that the PLA composite had an HDT up to 142℃ which is 90℃ higher than that of normal PLA products.Scanning electron microscopy(SEM)confirmed the fine dispersion of EVM-GMA particles,which facilitated to understand the toughening mechanism.Furthermore,the highly stereocomplexed PLA composites simultaneously exhibited excellent chemical and hydrolysis resistance.Therefore,these fascinating properties may extend the application range of sc PLA material as an engineering bioplastic.

关 键 词：PLA composites STEREOCOMPLEXATION Annealing Heat resistance TOUGHNESS 

分 类 号：TQ322.3[化学工程—合成树脂塑料工业] TB33[一般工业技术—材料科学与工程]