Melt Rheology of Poly(Lactic Acid) Plasticized by Epoxidized Soybean Oil  

作　　者：XU Yuqiong YOU Min QU Jinping 

机构地区：[1]Hubei Key Laboratory of Hydroelectric Machinery Designand Maintenance, China Three Gorges University, Yichang 443002,Hubei, China [2]National Engineering Research Center of Novel Equipmentfor Polymer Processing/Key Laboratory of Polymer ProcessingEngineering of Ministry of Education, South China University ofTechnology, Guangzhou 510640, Guangdong, China

出　　处：《Wuhan University Journal of Natural Sciences》2009年第4期349-354,共6页武汉大学学报（自然科学英文版）

基　　金：Supported by the Specialized Research Fund for the Doctoral Program of Higher Education of China (20030561014)

摘　　要：This study investigated that epoxidized soybean oil （ESO） was blended as plasticizer with poly （lactic acid） （PLA） and its effects on the melt rheological properties, such as melt flow index, apparent shear viscosity, and melt strength of the blends. PLA was blended by the twin-screw plastic extruder at five mass fractions： 3%, 6%, 9%, 12%, and 15% （based on PLA mass）. Melt flow index （MFI） was examined with a melt flow indexer. The results indicate that the blends of PLA/ESO had higher MFI than pure PLA, except for MFI at 9% reaching to the lowest point, even lower than that of pure PLA. Melt rheological properties were studied by a capillary rheometer in a temperature range of 160-180℃. The blends exhibited shear-thinning behavior and the apparent shear viscosity was well described by the power law in this shear rate region. The melt strength of PLA plasticized with 6% ESO reached the maximums. ESO was more effective in increasing the melt strength at the mass fractions less than 6%, which could toughen the blends to some extent. Therefore, the authors suggested the optimum addition level of 6%-9% ESO will get good melt rheological performance balance.This study investigated that epoxidized soybean oil （ESO） was blended as plasticizer with poly （lactic acid） （PLA） and its effects on the melt rheological properties, such as melt flow index, apparent shear viscosity, and melt strength of the blends. PLA was blended by the twin-screw plastic extruder at five mass fractions： 3%, 6%, 9%, 12%, and 15% （based on PLA mass）. Melt flow index （MFI） was examined with a melt flow indexer. The results indicate that the blends of PLA/ESO had higher MFI than pure PLA, except for MFI at 9% reaching to the lowest point, even lower than that of pure PLA. Melt rheological properties were studied by a capillary rheometer in a temperature range of 160-180℃. The blends exhibited shear-thinning behavior and the apparent shear viscosity was well described by the power law in this shear rate region. The melt strength of PLA plasticized with 6% ESO reached the maximums. ESO was more effective in increasing the melt strength at the mass fractions less than 6%, which could toughen the blends to some extent. Therefore, the authors suggested the optimum addition level of 6%-9% ESO will get good melt rheological performance balance.

关 键 词：poly （lactic acid） （PLA） epoxidized soybean oil melt flow index shear viscosity melt strength 

分 类 号：TQ325.12[化学工程—合成树脂塑料工业] TQ414.5