摘要
将等质量的左旋聚乳酸(PLLA)和右旋聚乳酸(PDLA)熔融共混,通过螺杆挤出机造粒制备了PLLA/PDLA切片。利用傅里叶红外光谱(FTIR)、X射线衍射(XRD)、差示扫描量热仪(DSC)、热失重(TGA)、冷热台显微镜(POM)和毛细管流变仪等设备对PLLA/PDLA共混材料的性能进行了系统地分析。结果表明,PLLA/PDLA共混材料是假塑性非牛顿流体,呈现切力变稀现象。立构复合晶的存在使复合物整体耐热性得到大幅提升,熔点约提高50℃,终止分解温度由377.59℃增加到386.75℃,热稳定性小幅提高。不同温度下复合物的等温结晶测试结果表明,采用130℃以上的温度进行结晶,形成的晶体结构规整、晶型稳定。结晶温度越低,PLLA/PDLA共混料晶体增长速度越快且晶粒体积越小,表现出明显的结晶动力学过程。
L-polylactic acid(PLLA)and right-handed polylactic acid(PDLA)of equal mass were melt blended,and pelletized by a screw extruder to prepare PLLA/PDLA chips.The properties of PLLA/PDLA blends were systematically analyzed by Fourier transform infrared spectroscopy((FTIR)),X-ray diffraction((XRD)),differential scanning calorimeter((DSC)),thermogravimetric((TGA)),hot and cold stage microscope(POM)and capillary rheometer.The results showed that the PLLA/PDLA blend material was a pseudoplastic non-Newtonian fluid with shear thinning property;the existence of stereo composite crystals greatly improved the overall heat resistance of the composite,and the melting point increased by about 50℃,the termination decomposition temperature increased from 377.59℃to 386.75℃,the thermal stability increased slightly.The isothermal crystallization tests of the composite at different temperatures showed that the crystal structure was regular and the crystal form was stable when the temperature was higher than 130℃.The lower the crystallization temperature,the faster the crystal growth rate of PLLA/PDLA blends and the smaller the grain size,showed an obvious crystallization kinetics process.
作者
骆佳美
凡凡
胡斌斌
冯宁宁
马博谋
刘勇
张辉
LUO Jiamei;FAN Fan;HU Binbin;FENG Ningning;MA Bomou;LIU Yong;ZHANG Hui(College of Material Science and Engineering,Donghua University,Shanghai 201620,China)
出处
《塑料》
CAS
CSCD
北大核心
2021年第5期87-92,共6页
Plastics
基金
国家重点研发计划(10Z106072017YFB0309300)。
