用PP与纳米Al2O3熔融共混法制备复合材料，再用超临界CO2间歇发泡法制备发泡材料，并对材料的结晶行为、力学性能、发泡行为和导热性能进行研究。结果表明，纳米Al2O3能提高复合材料的结晶和熔融温度，但会降低PP链段运动能力，当纳米Al2O3含量为7%时，复合材料的结晶度由纯PP的28.10%降至24.46%；纳米Al2O3具有刚性粒子的增强增韧协同效果，当纳米Al2O3含量为5%时，纳米Al2O3的骨架效应使得复合材料的拉伸强度达到33.9 MPa，继续提高其含量后复合材料的拉伸强度略微下降。由于纳米Al2O3的刚性粒子增韧效果，当纳米Al2O3含量达到7%时，复合材料的冲击强度可达到5.26 kJ／m2。纳米Al2O3起到异相泡孔成核剂作用，加入5%的纳米Al2O3后，发泡材料的泡孔密度提高至2.18×107个／cm3，其热导率在纳米Al2O3含量为7%时达到0.107 W／(m·K)。%Polypropylene (PP)ano Al2O3 composites were prepared by melt mixing,then the composites were foamed by batch-foaming method using supercritical CO2 as blowing agent. The crystallization behaviors and mechanical properties of the com-posites as well as the thermal conductivities and foaming behaviors of the foams were studied. The results show that the crystalliza-tion temperatureand melt temperature of the composites increase with the inducing of nano Al2O3,when nano Al2O3content is 7%, the crystallinity decreases from 28.10% to 24.46% due to the decreasing chain mobility of PP. The tensile and impact strength of the composites are enhanced by adding nano Al2O3,the tensile strength reaches 33.9 MPa when nano Al2O3content is 5%,the impact strength reaches 5.26 kJ/m2 when nano Al2O3 content is 7%. The cellular morphology and thermal conductivity of PPano Al2O3 foams are improved by adding nano Al2O3. When nano Al2O3 content is 5%,the foam’s cell density can reach 2.18×107 cell/cm3, and thermal conductivity increases to 0.107 W/(m·K) with addition of 7% nano Al2O3.
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