多元环氧扩链剂对聚乳酸等温结晶行为及力学性能的影响  

Effects of Multiple Epoxy Chain Extender on Isothermal Crystallization Behavior and Mechanical Performances of PLA

作　　者：陈文凯[1] 徐鼐[1] 潘莉莎[1] 陈烜[1] 石慧[1] 庞素娟[1] 黎坛 王俊峰 

机构地区：[1]海南大学材料与化工学院,海南海口570228 [2]海南赛诺实业有限公司功能薄膜国家地方联合工程研究中心,海南海口570125

出　　处：《塑料科技》2017年第5期53-58,共6页Plastics Science and Technology

基　　金：国家自然科学基金项目地区科学基金(51263007);海南省产学研一体化专项项目(cxy20150023);海南省重点研发计划高新技术类项目(ZDYF2016016)

摘　　要：采用多元环氧扩链剂(ADR)对聚乳酸(PLA)进行熔融扩链改性,得到PLA/ADR共混物。采用差示扫描量热仪(DSC)对共混物的熔体等温结晶行为进行表征和分析。结果表明:在110~120℃温度范围内,ADR的加入提高了PLA熔体的结晶速率;随着ADR用量的增加,PLA等温结晶速率明显提高,半结晶时间缩短。结合熔体流动速率和偏光显微镜分析,从分子运动能力和熔体黏度的角度解释了ADR对PLA等温结晶行为的影响机理。此外,研究了结晶度变化对PLA/ADR共混物拉伸性能和维卡软化温度(VST)的影响。当PLA/ADR(100/1.0)共混物的结晶度由1.7%提高到32.2%时,其拉伸强度由55.6 MPa提高到63.2 MPa,VST由61.9℃提高到156.9℃。结晶度的增大有利于PLA/ADR共混物力学性能和耐热性能的进一步提高。Poly（lactic acid）（PLA） was modified with a multiple epoxy chain extender（ADR） by meltmixing method.Isothermal melt-crystallization behaviors of PLA/ADR blends were investigated using a differential scanning calorimeter（DSC）.The isothermal crystallization kinetics analysis indicates that the isothermal crystallization rate of PLA enhances with the introduction of ADR while crystallized at the temperature range of 110~120℃.With the increasing of ADR loading,the isothermal crystallization rate of PLA increases significantly,as well as the crystallization halftime reduces.The effect of ADR on the isothermal crystallization behavior of PLA was explained from the point of view of molecular motion and melt viscosity based on melt flow rate（MFR） and polarizing optical microscope（POM） measurements.In addition,the impact of crystallinity on tensile performance and vicat softening temperature（VST） of PLA/ADR blends were investigated.While the crystallinity of PLA/ADR（100/1.0） blend increases from 1.7% to 32.2%,its tensile strength increases from 55.6 MPa to 63.2 MPa.Meanwhile,the VST increases from 61.9℃ to 156.9℃.The results show that the increase of crystallinity can further enhance the mechanical performances and heat resistance of PLA/ADR blends.

关 键 词：聚乳酸 扩链剂 结晶动力学 拉伸性能 维卡软化温度 

分 类 号：O633.14[理学—高分子化学]