高倍率聚丙烯共混发泡材料的制备及性能研究

Study on Preparation and Properties of Polypropylene Blends with High Expansion Ratio

以不同共混比例的低熔点聚丙烯和普通共聚聚丙烯为原料、CO2为发泡剂,制备了聚丙烯共混发泡材料。采用差示扫描量热仪(DSC)、傅里叶红外光谱(FTIR)和旋转流变仪考察了该共混改性聚丙烯的熔融性能、乙烯含量以及熔体强度,并通过扫描电子显微镜(SEM)分析了改性聚丙烯发泡后的泡孔形态。结果表明:低熔点聚丙烯的加入使共混体系的熔体强度显著降低,当其用量为20份时,发泡材料的泡孔形态达到最佳,此时发泡倍率、泡孔直径和泡孔密度分别为14.38倍、658μm和1.54×105个/cm3。

The foamable low-melting-point polypropylene/common copolymerized polypropylene blends with different ratios were prepared using CO2 as the foaming agent. The differential melting calorimetry(DSC), Fourier transform infrared spectroscopy(FTIR) and rotational rheometer were used to characterize the melting properties, ethylene content and melt strength of the modified polypropylene, and the morphology of the cells after foaming was analyzed by scanning electron microscopy(SEM). The results show that, the melt strength of the polypropylene blends can be significantly reduced after adding the low melting point polypropylene. When the dosage of low melting point polypropylene is 20 phr, the cell morphology of the foamed material can reach the optimum, the expansion ratio, pore diameter and cell density are 14.38 times, 658 μm and 1.54×105 cells/cm3, respectively.