摘要
针对聚乳酸(PLLA)结晶速率慢、韧性差的不足,该研究通过熔融共混挤出法添加成核剂苯基膦酸锌(TMC-210)来提高PLLA的结晶性能,同时添加弹性体聚酯橡胶(TPEE)来增加其韧性,从而达到改性PLLA的目的。利用差示扫描量热仪(DSC)、X射线衍射仪(XRD)、偏光显微镜(POM)、扫描电子显微镜(SEM)、力学性能测试等手段对改性后的PLLA进行表征。结果表明,在PLLA/TMC-210/TPEE聚合物中添加TMC-210可提高PLLA的结晶速度,添加0.2%(质量比)TMC-210后PLLA结晶峰温度达到122.2℃,TMC-210的添加使得PLLA冷结晶峰消失,低含量的TPEE有利于PLLA共混体系的结晶,含量过高则不利于共混体系的结晶。XRD测试结果显示,TMC-210和TPEE的添加对PLLA晶型没有影响;但是TPEE的加入极大地提高了PLLA的韧性,纯PLLA的冲击强度为3.03 kJ·m^-2,在PLLA作为基体的前提下,当TPEE含量为50%(质量比)时,PLLA的冲击强度达到20.7 kJ·m^-2,比未添加TPEE的PLLA高5.83倍。
In this work,TMC-210 and TPEE substances were selected as modifiers to mediate the crystallization and melting behaviors and mechanical properties of PLLA at different levels by melt blending method,which was mainly aimed at the problem that the crystallization rate of PLLA was too slow and that toughness of PLLA was too poor.The effect of TMC-210 and TPEE on the crystallization and melting behaviors,spherulite morphology,crystal structure,and mechanical properties of the blends were systematically investigated by differential scanning calorimetry(DSC),polarized optical microscopy(POM),X-ray diffraction(XRD),scanning electron microscope(SEM),and mechanical test.It was found that TMC-210 significantly accelerated the crystallization of PLLA in PLLA/TMC-210/TPEE blends.There was no crystal peak,when we added 0.2%(mass ratio)TMC-210 to the PLLA,the crystallization temperature of PLLA increased to 122.2℃,and the addition of TMC-210 made the cold crystallization temperature of PLLA disappeared.The test results of XRD showed that the addition of TMC-210 and TPEE had no influence on the crystal structure of PLLA.However,the introduction of TPEE greatly improved the toughness of PLLA,the impact strength of pure PLLA was 3.03 kJ·m^-2,when the TPEE content was 50%(mass ratio),impact strength of PLLA(20.7 kJ·m^-2)was 5.83 times higher than that of pure PLLA.
作者
师盟盟
罗发亮
SHI Mengmeng;LUO Faliang(State Key Laboratory of High-efficiency Coal Utilization and Green Chemical Engineering,Ningxia University,Yinchuan 750021,China)
出处
《材料导报》
EI
CAS
CSCD
北大核心
2020年第12期12191-12195,共5页
Materials Reports
基金
宁夏高等学校一流学科建设(化学工程与技术学科)资助项目(NXYLXK2017A04)。
关键词
聚乳酸
弹性
韧性
结晶
聚合物
polylactic acid
elasticity
toughness
crystallization
polymers
