关于PIB弹性体改性PP对发泡性能的影响的研究

Study on the Influence of PP Modified by PIB Elastomer on Foaming Performance

超临界二氧化碳发泡聚丙烯(PP)与原料的熔体强度关系很大。采用PP与聚异丁烯(PIB)共混的方式来提高PP的熔体强度,研究了不同PIB质量分数下,样品中PP组分的结晶行为的变化,拉伸性能和韧性的变化。然后用自制的发泡设备研究样品的发泡性能与PIB质量分数的关系。结果表明PIB对PP组分的结晶行为影响很小,并发现随着PIB质量分数的增加,样品的拉伸强度和模量逐渐下降,而韧性逐渐增加。随着PIB质量分数的增加,发泡样品的发泡倍率和发泡直径先增加而后降低,泡孔密度的变化趋势正好相反,在PIB质量分数为5%时,发泡倍率和泡孔平均直径达到最大值,而泡孔密度为最小值,同时泡孔直径分布也最窄。

Foaming polypropylene(PP)with supercritical CO 2 had a great relationship with the melt strength of raw materials.Blending PP with polyisobutylene(PIB)could improve the melt strength of PP.The changes in the crystallization behavior,tensile properties and toughness of PIB/PP composites with different amounts of PIB had been studied.The relationship between foaming properties of samples and mass fraction of PIB had been studied with self-foaming equipment.The results show that PIB has little effect on the crystallization behavior of PP components.As the PIB mass fraction increases,the tensile strength and modulus of the samples gradually decrease,while the toughness gradually increases.With the increase of the PIB mass fraction,the foaming ratio and foaming diameter of the foamed samples first increases and then decreases.The trend of the cell density is exactly the opposite.When the PIB mass fraction is 5%,the foaming ratio and the average cell diameter both could reach the maximum value,while the cell density is the minimum value,and the distribution of cell diameter is also the narrowest.