基于相形态结构的PLA/PBS共混物微孔发泡行为  

Microcellular Foaming Behavior of PLA/PBS Blends Based on Phase Structure

作　　者：余鹏 项佩 高金玲 李媛 YU Peng;XIANG Pei;GAO Jinling;LI Yuan(Hubei Provincial Key Laboratory of Green Materials for Light Industry,School of Materials and Chemical Engineering,Hubei University of Technology,Wuhan 430068;School of Automotive Engineering,Wuhan Huaxia University of Technology,Wuhan 430223)

机构地区：[1]湖北工业大学材料与化学工程学院,绿色轻工材料湖北省重点实验室,武汉430068 [2]武汉华夏理工学院汽车工程学院,武汉430223

出　　处：《材料导报》2019年第20期3524-3530,共7页Materials Reports

基　　金：湖北省教育厅青年人才项目(Q20171409);湖北工业大学博士科研启动项目(BSQD2015005)~~

摘　　要：将不同组分的聚丁二酸丁二醇酯(PBS)添加到聚乳酸(PLA)基体中形成非相容共混体系,利用超临界二氧化碳发泡方法制备出孔间高度连通的微孔发泡材料。将PBS添加到PLA基体中降低了共混体系的熔体粘度,异相成核作用致使泡孔密度增加、泡孔尺寸和泡孔壁厚度减小,这都将有利于增大泡孔连通的概率。泡孔结构数据表明,当PBS含量为20%(质量分数)、发泡温度为100℃时,得到的泡孔尺寸最小(9.51μm),泡孔密度最大(18.6×10~8cells/cm^3~),开孔率最大(98.2%)。基于PLA/PBS相态结构提出了共混物发泡样品的开孔机理,熔体粘度较低的PBS分散相随着泡孔长大而被拉伸变形直至破裂,熔体粘度较高的基体相PLA可作为泡孔的支撑骨架而不至于塌陷。Poly(butylenes succinate)(PBS)with various contents were added to polylactic acid(PLA)matrix to form immiscible polymer blend.Supercritical carbon dioxide microcellular foaming method was used to fabricate microcellular materials with highly interconnected cells.The visco-sity of PLA/PBS blends decreased because of the addition of PBS content,meanwhile,owing to heterogeneous nucleation effect,the cell density was increased while the cell size and cell wall thickness was decreased,which benefits to improve probability of cell wall connected.The cell structure data reveals that the smallest cell size of 9.51μm,the largest cell density of 18.6×10^8 cells/cm 3 and the maximum opening rate of 98.2%was obtained when foamed at 100℃in blend with 20wt%PBS content.Cell opening mechanism of blend foaming samples was proposed based on PLA/PBS phase structure.Dispersion PBS phase with lower melt viscosity is stretched until it ruptured during the cell growing process,while PLA matrix with higher melt viscosity could be used as supporting skeleton to prevent cell collapse.

关 键 词：聚乳酸 超临界二氧化碳 微观结构 泡孔形态 

分 类 号：TQ328[化学工程—合成树脂塑料工业]