低含量增塑剂PEG对PLA性能的影响  

Effects of Low Content Plasticizer PEG on PLA Performances

作　　者：朱艳[1] 张显勇[1] 贾仕奎[1] 王忠[1] 付蕾[1] 陈立贵[1] Zhu Yan;Zhang Xianyong;Jia Shikui;Wang Zhong;Fu Lei;Chen Ligui(School of Materials Science and Engineering,Shaanxi University of Technology,Hanzhong 723000,China)

机构地区：[1]陕西理工大学材料科学与工程学院

出　　处：《工程塑料应用》2019年第12期1-6,20,共7页Engineering Plastics Application

基　　金：国家自然科学基金项目(51703121)

摘　　要：以质量分数不高于2%的聚乙二醇(PEG)为增塑剂,采用熔融共混法,利用双螺杆挤出机制备系列聚乳酸(PLA)/PEG共混物,并对其断面形貌、结晶行为、热稳定性和力学性能进行研究。结果表明,PEG能够在PLA基体中均匀分散,低含量PEG的引入未改变PLA晶型;随着PEG含量的增加,PLA/PEG共混物的冷结晶焓逐渐减小,而熔融焓逐渐增大,结晶度在PEG质量分数为2%时达到最大值37.65%,较纯PLA提高了54.43%;添加PEG后,PLA晶体由球晶变为不规则的多边形晶体。随着PEG含量的增加,共混物拉伸强度和缺口冲击强度呈先上升后下降的趋势。当PEG质量分数为1.6%时,PLA/PEG共混物的拉伸强度达到最大,其值为66.75 MPa,较纯PLA提高了14.3%;当PEG质量分数为1.2%时,缺口冲击强度达到最大,其值为11.4 kJ/m2,较纯PLA提高了51.39%,表明低含量的增塑剂PEG也能起到增韧PLA的效果。Polyethylene glycol(PEG)with low content(≤2wt%)was used as a plasticizer,and a series of polylactic acid(PLA)/PEG blends were prepared by using a twin-screw extruder by melt blending.Fracture surface morphology,crystallization behavior,thermal stability and mechanical properties of PLA/PEG blends were studied.The results show that PEG can be uniformly dispersed within the PLA matrix,the addition of low content of PEG do not change the crystal form of PLA,with the increase of PEG,the cold crystallization enthalpy of PLA/PEG blends decrease gradually,while the melting enthalpy gradually increase.The crystallinity reaches the maximum of 37.65%when the content of PEG is 2wt%,which is 54.43%higher than pure PLA.The crystal of PLA changes from spherulites to irregular polygonal crystals with the addition of PEG.With the increase of PEG content,the tensile strength and notched impact strength of PLA/PEG blends first increase and then decrease.When the content of PEG is 1.6wt%,the tensile strength reaches a maximum of 66.75 MPa,which is 14.3%higher than that of pure PLA.When the content of PEG is 1.2wt%,the maximum value of the notched impact strength reaches 11.4 kJ/m2,which is 51.39%higher than that of pure PLA and indicates the plasticizer PEG with low content can also enhance the toughness of PLA.

关 键 词：聚乳酸 聚乙二醇 断面形貌 结晶行为 力学性能 

分 类 号：TQ321[化学工程—合成树脂塑料工业]