蓖麻油基预聚物原位反应增韧聚乳酸  

In-Situ Reaction of Castor Oil-Based Prepolymer Toughened Polylactic Acid

作　　者：李志勇 黄宏巍 李明专 程刊 鲁圣军[1,2] Zhiyong Li;Hongwei Huang;Mingzhuan Li;Kan Cheng;Shengjun Lu(College of Materials and Metallurgy,Guizhou University,Guiyang 550025,China;National Engineering Research Center for Compounding and Modification of Polymeric Materials,Guiyang 550014,China)

机构地区：[1]贵州大学材料与冶金学院,贵州贵阳550025 [2]国家复合改性聚合物材料工程技术研究中心,贵州贵阳550014

出　　处：《高分子材料科学与工程》2020年第9期66-72,共7页Polymer Materials Science & Engineering

基　　金：国家自然科学基金资助项目(51563002);贵州省“百层次”创新型人才项目黔科合平台人才项目([2016]5653)。

摘　　要：以4,4′-二苯基甲烷二异氰酸酯(MDI)为原料,在转矩流变仪中进行原位共混,制备出具有良好拉伸韧性的聚乳酸(PLA)/蓖麻油基聚氨酯预聚物(COPUP)共混物。对PLA/COPUP共混物的熔体扭矩、微观形貌、结晶性、热稳定性、流变行为和力学性能进行了系统分析,探讨了COPUP含量对共混物性能的影响。研究结果表明,随着COPUP含量增加,熔体扭矩值增大,MDI在PLA基体中与蓖麻油之间原位反应形成了化学交联结构。扫描电镜分析得知,共混物PLA/COPUP的微观相形态呈相分离结构,COPUP颗粒作为分散相均匀分散在PLA基体中。随着COPUP含量的增加,共混物的结晶能力和热稳定性降低,交联程度增大,断裂伸长率呈增大的趋势。当COPUP质量分数为30%时,拉伸强度为42.2 MPa,断裂伸长率达到最大值(断裂伸长率为180%),约为纯PLA(断裂伸长率为5%)的34倍。Polylactic acid(PLA)/castor oil-based polyurethane prepolymer(COPUP)blends with good tensile toughness were prepared by in-situ blending of 4,4′-diphenylmethane diisocyanate(MDI)through torque rheometer.The melt torque,microstructure,crystallinity,thermal stability,rheological behavior and mechanical properties of PLA/COPUP blends were analyzed.The effect of COPUP content on the properties of the blends was discussed.The results show that with the increase of COPUP content,the melt torque value increases,and the in-situ reaction of MDI in the PLA matrix with castor oil forms two cross-linking structures:chemical cross-linking and physical cross-linking.SEM analysis shows that the microscopic phase morphologies of the PLA/COPUP blends are phase-separated,and COPUP particles are uniformly dispersed in PLA matrix as dispersed phase.With the increase of COPUP content,the crystallization ability and thermal stability of the blends decrease,the degree of crosslinking increases,and the elongation at break shows an increasing trend.When the mass fraction of COPUP is 30%,the tensile strength is 42.2 MPa,and the elongation at break reaches the maximum value(elongation at break is 180%),which is about 34 times that of neat PLA(elongation at break is 5%).

关 键 词：聚乳酸 聚氨酯预聚物 熔融共混 流变行为 增韧 

分 类 号：TQ323.41[化学工程—合成树脂塑料工业]