超临界CO_2增强聚合物加工的研究与应用进展

Review of Supercritical Carbon Dioxide Assisted Polymer Processing

对超临界CO2环境中聚合物加工方法的研究、应用现状与进展进行了综述。基于SC-CO2对聚合物的增塑作用,可开发出许多相关用途,如聚合物改性、聚合物共混、聚合物复合材料、多孔微泡沫材料、微粒化以及聚合物浸渍/灌注/插嵌等。在对研究现状和结果进行梳理总结后,认为SC-CO2对聚合物加工过程的增强作用机理可归结为:SC-CO2对聚合物的溶胀,导致增塑,进而降低了聚合物的玻璃化温度、黏度、表面张力,增强了小分子化合物在聚合基质中的扩散系数。此外,CO2作为绿色溶剂,是有机溶剂的良好替代品,因此具有广阔的应用前景。

The new research advances in polymer processing with supercritical CO2 were reviewed.The effects of supercritical CO2 on polymer processing,such as polymer modification,polymer blending,formation of polymer composites,microcellular foaming,particle production,and infusion of additives,were discussed.Its unique properties such as gas-like diffusivity and liquid-like density allow replacing conventional,often noxious,solvents with supercritical CO2.Though only a few polymers are soluble in supercritical CO2,it is quite soluble in many polymers.Dissolved CO2 causes polymers to be plasticized,resulting in considerable reduction of viscosity of molten polymer,glassy transition temperature,and growth of diffusitivity of additives,very important properties for the applications stated above.