不同分子量PCL增韧PLA的结构与性能  

Property and Structure of PLA Toughened by Different Molecular Weight PCL

作　　者：孟兵[1] 郑金辉[1] 孙建丽[1] 

机构地区：[1]成都航空职业技术学院,成都610100

出　　处：《工程塑料应用》2016年第5期107-111,共5页Engineering Plastics Application

基　　金：四川省教育厅重点项目<透明全降解合金PLA/PPC包装材料研究>(13ZA0052);四川省教育厅四川高校校企联合<航空制造工艺>应用技术创新基地项目前期成果之一

摘　　要：采用两种不同分子量的聚(ε-己内酯)(PCL)(粘均分子量60 000和3 000)与聚乳酸(PLA)在175℃下共混10 min制备PLA/PCL共混物。通过动态流变、扫描电子显微镜(SEM)和力学性能等研究了PLA/PCL共混物的结构和性能。动态流变显示,在PCL低含量(质量分数小于15%)时,PCL与PLA是相容的,质量分数为15%时PCL与PLA表现出明显的相分离行为。SEM显示,随着PCL含量的增加,PCL相的尺寸变大;低分子量PCL(L-PCL)的相尺寸明显大于高分子量PCL(H-PCL),而且相形态不是规则的球状。随着PCL含量的增加,共混物的拉伸强度下降,而断裂伸长率增加。当H-PCL质量分数为8.3%时,PLA/H-PCL共混物的断裂伸长率为137.32%。当H-PCL质量分数为15%时,其断裂伸长率高达232.76%。在添加相同含量PCL时,PLA/H-PCL共混物的拉伸强度高于PLA/L-PCL;而PCL质量分数<8%时,共混物的断裂伸长率相差不多,当PCL质量分数大于8%时,PLA/H-PCL共混物的断裂伸长率明显比PLA/L-PCL共混物的高。Ductile PLA/poly(ε-caprolactone) (PCL) blends composed of poly(lactic acid) (PLA) and two different molecular weight PCL were prepared by melt blending at 175℃ for 10 min. The dynamic rheological, mechanical properties, DSC and phase morphology of PLA/PCL blends were investigated. Dynamic rheological result shows that PLC and PLA is immiscible at lower PCL content (<15%); and when PCL content is 15% the melt shows obvious phase separation behavior. SEM shows that PCL phase size increases with the increase of PCL content, and the phase of L-PCL is significantly greater than that of H-PCL, and phase morphology of L-PCL are not more regular. With the increase of PCL content, the tensile strength decreases and elongation at break increases. When the mass fraction of H-PCL is 8.3%, elongation at break of PLA/H-PCL blend reaches 137.32%, and that elongation at break is 232.76% with the 15% H-PCL. With same PCL content, the tensile strength of PLA/H–PCL is higher than that of PLA with L-PCL. When the mass fraction of PCL is less than 8%, the elongations at break of the two PLA/PCL blends have no notable difference. When the mass fraction of PCL is more than 8%, the elongation atbreak of PLA/H-PCL blend is significantly higher than that of PLA/L-PCL blend.

关 键 词：聚乳酸 聚(ε-己内酯) 动态流变 共混 

分 类 号：TQ320.64[化学工程—合成树脂塑料工业]