氯化钠填充制备聚乳酸多孔复合材料

Preparing Porous Polylactic Acid Microstructure by Leaching High Content NaCl/Polylactic Acid Blends

采用氯化钠(NaCl)、聚氧化乙烯(PEO)填充混合的方法制备聚乳酸(PLA)多孔复合材料,借助于扫描电镜、差示扫描量热分析、X射线衍射等测试方法,研究了配方与混炼工艺对多孔材料泡孔结构、孔隙率和热性能的影响。结果表明,提高NaCl含量使多孔材料的孔隙率增大;PEO的加入使多孔材料出现连通孔结构;当NaCl含量为80%,PEO含量为10%,混炼机转速为700r/min时的泡孔连通性最好,孔隙率高达88.3%;随着一定量PEO的加入,PLA多孔材料的泡孔连通性增强,结晶度降低;提高混炼机转速可增强泡孔连通性,提高结晶度。

To achieve a porous polylactic acid(PLA)microstructure,high filling content NaCl/PLA and NaCl/PEO/PLA blends were prepared by high speed internal mixing and then subjected to thorough leaching to achieve the porous morphology.The influence of processing parameters,e.g.blends formula and mixing speed,on cell morphology,porosity and thermal stability was investigated,and sequentially characterized by SEM,DSC and XRD.The results indicate that the system porosity arises with increase of the NaCl filling content,and PEO addition significantly improves the system pore interconnectivity.The increase of polyethylene oxide(PEO)content in blends shows positive influence on the increase of PLA pore interconnectivity,which therefore limit the system crystallinity.In clear contrast,increasing the mixing speed improve both pore interconnectivity and bulk crystallinity of the PLA structure.Finally,an optimal processing condition is proposed with a blend formula of mass fraction of 80% NaCl and 10% PEO at a mixing speed of 700r/min.