聚乳酸/有机改性蒙脱土复合材料的制备及结晶性能研究

Preparation and Crystallization Behavior of PLA/OMMT Composites

以多巴胺作为有机改性剂,通过溶液法处理蒙脱土(MMT)制得有机改性蒙脱土(OMMT),并经熔融共混法制备PLA、OMMT质量百分比为99∶1的PLA/OMMT复合材料。采用X射线衍射(XRD)、傅里叶红外(FTIR)及热重(TG)对OMMT进行测试和分析,确认MMT片层上接枝有聚多巴胺分子。研究发现:在聚合物反应中随着多巴胺用量的增加和反应时间的延长,MMT片层上的聚多巴胺含量增大,MMT片层间距增大;PLA/OMMT复合材料的冷结晶温度降低、晶粒尺寸变小、结晶度增大,OMMT起到很好的成核剂作用,促进了PLA结晶性能的提高。

In this study,sodium montmorillonite（MMT）was organically modified with dopamine to obtain organically intercalated MMT（OMMT）by solution method.PLA/OMMT composites were prepared by melt blending,and the mass ratio of PLA/OMMT was fixed at 99∶1.X-ray powder diffraction（XRD）,fourier infrared（FTIR）and thermal gravimetric（TG）were employed to investigate the interior structure of OMMT.The experimental results indicated that DOPA had been successfully polymerized into PDOPA on MMT and the d-spacing had been increased.OMMT could act as a nucleating agent to accelerate the crystallization of PLA.This ascribed from the admirable interfacial adhesion between OMMT and PLA.