以聚苯乙烯(PS)，PS/聚乙烯(PS/PE)共混体系和PS/纳米CaCO3(PSano-CaCO3)复合体系为研究对象，以超临界CO2为发泡剂，选择典型工艺条件开展了发泡实验，采用扫描电子显微镜(SEM)观察泡孔结构，比较分析了不同工艺条件下的发泡行为，为利用PS，PS/PE共混体系和PSano-CaCO3复合体系提供研究基础。研究结果表明，PS具有较好的成孔性能，在发泡压力为22 MPa、发泡温度为80℃和饱和时间为2 h时，可制得泡孔孔径为(11.19±2.12)μm、泡孔密度为5.31×107个/cm3、发泡倍率2.64的微孔发泡材料。与PS相比，在相同工艺条件下，当添加PE的质量分数为10%时，PS/PE共混体系的泡孔孔径显著减小，泡孔密度有所提高，可通过调节工艺条件调整泡孔形貌；添加质量分数为5%经硅烷偶联剂表面改性的nano-CaCO3，可促进PSano-CaCO3复合体系的泡孔成核，改善其泡孔形态，增加泡孔密度，减小泡孔孔径。%Foaming of polystyrene(PS),PS/polyethylene(PE) blend systems and PSano-CaCO3 composite systems by using supercritical CO2 as foaming agent at different foaming conditions were studied. The microcellular structure was observed by scanning electron microscopy. The foaming behaviors of them were compared. It can provide research basis for preparing PS,PS/PE blend systems and PSano-CaCO3 composite systems microcellular materials. Results show that PS has good foamability. When saturation pressure is 22 MPa,forming temperature is 80℃and saturation time is 2 h,the cell diameter,the cell density and volume expansion ratio of microcellular PS is (11.19± 2.12) μm,5.31×107 cells/cm3 and 2.64 respectively. Compared with PS,PS/PE blend systems show better foamability with much smaller cell diameter and higher cell density at same foaming conditions when mass fraction of PE is 10%. The cell characteristics of foamed PS/PE blend systems could be tailored by altering the processing conditions. When mass fraction of surface modified nano-CaCO3 by silane coupling agent is 5%,pore nucleation is promoted and the pore morphology is improved,the cell size is decreased and cell density is increased in PSano-CaCO3 composite systems.
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