聚乳酸/有机蒙脱土纳米复合材料的制备与性能

Preparation and its property of poly(lactic acid)/OMMT nano-composites

采用熔融共混法在双螺杆挤出机中制备了聚乳酸/有机蒙脱土(PLA/OMMT)纳米复合材料。用X射线衍射分析(XRD)和透射电镜(TEM)观察OMMT层间距的变化以及材料的微观结构。用示差扫描量热仪(DSC)研究了其热性能和结晶度的变化,并考察了纳米复合材料的拉伸强度和断裂伸长率。测试结果表明:OMMT的层间距由1.801 nm扩大到3.530 nm,聚乳酸(PLA)高分子链插入到蒙脱土的片层间,有机蒙脱土主要以剥离状态分散在PLA基体中,加入质量分数为3%OMMT的复合材料不仅使材料的拉伸强度和断裂伸长率达到62.8 MPa和14.2%,还提高了材料的结晶度,PLA/OMMT纳米复合材料的结晶度相对于纯PLA增加了73.9%。

PLA/OMMT nano-composites were prepared through melt intercalation in twin-screw extruder.The changes of the basal spacing between layers and the structure of the nano-composites were investigated by X-ray diffraction(XRD) and transmission electron microscopy(TEM).The thermal properties and crystallinity of PLA/OMMT nano-composites were studied by DSC,tensile strength and breaking elongation rate of the composites were also tested.The results show that the spacing of layers of OMMT increases from 1.801 nm to 3.530 nm,the PLA intercalates into the silicate layers and expands the basal spacing,the use of 3%(mass fraction) of OMMT not only increases the tensile strength and breaking elongation rate to 62.8 MPa and 14.2%,but also improves the crystallinity of PLA/OMMT nano-composites by 73.9%.