A kind of high melt strength homopolypropylene foaming material was prepared with supercritical CO2 as blowing agent. The effect of supercritical CO2 content on the foaming process was studied in a continuous extrusion foaming process. The die pressure of the foaming extruder, expansion ratio and cell size of the samples decreased while the cell population density increased with the augmentation of the supercritical CO2 content. Polypropylene(PP) foams with expansion ratio as high as 13 were obtained when the mass fraction of the supercritical CO2 were 3％ and 5％. Microcellular PP foams with cell size in the range of 10-30 μm and cell population density of 6.84×107 cells/cm3 were produced when setting the mass fraction of supercritical CO2 at 7％ and temperature at 123 ℃, respectively.%以超临界CO2为发泡剂,在连续挤出发泡过程中研究了超临界CO2用量对高熔体强度均聚聚丙烯(PP)发泡成型过程的影响.随着超临界CO2用量的增加,发泡挤出机口模压力降低,试样发泡倍率降低,泡孔尺寸变小,泡孔密度提高.在w(CO2)为3%,5%时,得到发泡倍率最高为13左右的PP发泡材料.w(CO2)为7%,发泡温度为123℃时,制备了孔径为10～30μm,泡孔密度为6.84x107个/cm3 的PP微孔泡沫塑料.
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