Significant enhancement of crystallization kinetics of polylactide in its immiscible blends through an interfacial effect from comb-like grafted side chains  

作　　者：Yin Chen Yaqiong Zhang Feng Jiang JunyangWang Zhaohua Xu Zhigang Wang 

机构地区：[1]CAS Key Laboratory of Soft Matter Chemistry,Hefei National Laboratory for Physical Sciences at the Microscale,Department of Polymer Science and Engineering,University of Science and Technology of China,Hefei 230026,China [2]Department of Material Technology,Jiangmen Polytechnic,Jiangmen 529090,China

出　　处：《Science China Chemistry》2016年第5期609-618,共10页中国科学（化学英文版）

基　　金：supported by the National Basic Research Program of China (2012CB025901);the National Natural Science Foundation of China (21174139);the Open Research Fund of State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences

摘　　要：A significant enhancement in isothermal crystallization kinetics of biodegradable polylactide(PLA) in its immiscible blends can be accomplished through blending it with a comb-like copolymer. PLA was blended with poly(ethylene glycol) methyl ether acrylate(PEGA) and poly[poly(ethylene glycol) methyl ether acrylate](PPEGA, a comb-like copolymer), respectively. The results measured from phase contrast optical microscopy(PCOM) and differential scanning calorimetry(DSC) indicate that PLA and PEGA components are miscible, whereas PLA and PPEGA components are immiscible. The study of crystallization kinetics for PLA/PEGA and PLA/PPEGA blends by means of polarized optical microscopy(POM) and DSC indicates that both PEGA and PPEGA significantly increase the PLA spherulitic growth rates, G, although PLA/PPEGA blends are immiscible and the glass transition temperatures of PLA only have slight decreases. PPEGA component enhances nucleation for PLA crystallization as compared with PEGA component owing to the heterogeneous nucleation effect of PPEGA at the low composition of 20 wt%, while PLA crystallization-induced phase separation for PLA/PEGA blend might cause further nucleation at the high composition of 50 wt%. DSC measurement further demonstrates that isothermal crystallization kinetics can be relatively more enhanced for PLA/PPEGA blends than for PLA/PEGA blends. The "abnormal" enhancement in G for PLA in its immiscible blends can be explained by local interfacial interactions through the densely grafted PEGA side chains in the comb-like PPEGA, even though the whole blend system(PLA/PPEGA blends) represents an immiscible one.A significant enhancement in isothermal crystallization kinetics of biodegradable polylactide （PLA） in its immiscible blends can be accomplished through blending it with a comb-like copolymer. PLA was blended with poly（ethylene glycol） methyl ether acrylate （PEGA） and poly[poly（ethylene glycol） methyl ether acrylate] （PPEGA, a comb-like copolymer）, respectively. The results measured from phase contrast optical microscopy （PCOM） and differential scanning calorimetry （DSC） indicate that PLA and PEGA components are miscible, whereas PLA and PPEGA components are immiscible. The study of crystalliza- tion kinetics for PLA/PEGA and PLA/PPEGA blends by means of polarized optical microscopy （POM） and DSC indicates that both PEGA and PPEGA significantly increase the PLA spherulitic growth rates, G, although PLA/PPEGA blends are immisci- ble and the glass transition temperatures of PLA only have slight decreases. PPEGA component enhances nucleation for PLA crystallization as compared with PEGA component owing to the heterogeneous nucleation effect of PPEGA at the low compo- sition of 20 wt%, while PLA crystallization-induced phase separation for PLA/PEGA blend might cause further nucleation at the high composition of 50 wt%. DSC measurement further demonstrates that isothermal crystallization kinetics can be rela- tively more enhanced for PLA/PPEGA blends than for PLA/PEGA blends. The ＂abnormal＂ enhancement in G for PLA in its immiscible blends can be explained by local interfacial interactions through the densely grafted PEGA side chains in the comb-like PPEGA, even though the whole blend system （PLA/PPEGA blends） represents an immiscible one.

关 键 词：biodegradable polymer SPHERULITE growth rate phase separation NUCLEATION 

分 类 号：O633.14[理学—高分子化学]