在超临界CO_2中制备生物可降解PEC/OMMT纳米复合材料

PREPARATION OF BIODEGRADABLE PEC/OMMT NANOCOMPOSITES IN SUPERCRITICAL CARBON DIOXIDE FLUID

将聚碳酸亚乙酯(PEC)与有机蒙脱土(OMMT)在超临界CO2(sc-CO2)中溶胀并混合,制备了生物可降解PEC/OMMT纳米复合材料。采用X射线衍射仪、热失重分析仪、差示扫描量热仪及万能电子拉力机等对PEC/OM-MT纳米复合材料的性能进行表征和分析。结果表明,70℃下制备的PEC/OMMT复合材料为插层型纳米复合材料;该复合材料的热稳定性和玻璃化转变温度都得到较大改善;加入少量OMMT,复合材料的拉伸性能得到明显提高。与熔融插层法和溶液插层法相比,sc-CO2法既可以解决PEC在熔融插层中面临的热降解问题,也可以避免溶液插层中使用大量有机溶剂造成的污染问题,是制备PEC/OMMT纳米复合材料的一种新方法。

Poly（ethylene carbonate） （PEC） and organophilic montmorillonite（OMMT） were swelled and mixed in supercritical carbon dioxide（ sc-CO2 ） to prepared biodegradable PEC/OMMT nanocomposites. The PEC/OMMT nanocomposites were investigated using X-ray diffraction （XRD） , thermal gravimetric analysis （TGA） , differential scanning calorimetric （DSC） , and electronic tensile tester. It was found that PEC/OMMT nanocomposites prepared at 70℃ had an intercalated structure. The thermal stability and glass transition temperature of PEC/OMMT nanoeomposites were improved obviously. With low OMMT content, the PEC/OMMT nanocomposites exhibited better tensile performance than neat PEC. Compared with melt intercalation method and solution intercalation method, the sc-CO2 method could avoid the thermal degradation of PEC occurred during melt intercalation and the pollution of organic solvent used in solution intercalation. The sc-CO2 method was a novel method for preparing PEC/OMMT nanocomposites.