剪切对聚合物微孔发泡成型过程的影响

Effect of Shearing on the Microcellular Foaming Process of Polymer

分别运用有螺纹转子系统和无螺纹转子系统进行试验,并分析研究剪切作用对聚合物微孔发泡成型过程3个阶段的影响。结果表明,增加剪切作用有利于气体的分散和溶解,减少均相体系形成的时间,提高均相体系形成的质量;在较强的剪切作用下,较小的分子基团也能形成稳定的气泡核,在聚合物熔体中形成大量均匀细密分布的气泡核;但长时间、过强的剪切作用会导致气泡塌陷。

The experiments were based upon the systems of rotor with screw and rotor without screw and studied the effects of shearing on the three microcellular foaming process of polymer. The results showed that increasing shearing was beneficial to the dispersion and dissolution of gas, reduction of formation time homogeneous solution and higher quality of homogeneous solution. Under strong shear field, smaller molecular groups could form stable molecular groups which resulted in production of large quantities of bubble nuclear in polymer melt. But an excess of long time and shearing could make the bubble collapse.