高密度聚乙烯流变结晶性能对发泡的影响研究

Effects of Rheological and Crystalline Properties of PE-HD on Its Foaming Process

采用差示扫描量热仪(DSC)和Hakke平板旋转流变仪测试了2种不同高密度聚乙烯(PE-HD)的热性能和动态流变性能,结合间歇发泡实验探究了PE-HD的发泡性能。结果表明,PE-HD的结晶速率以及黏弹特性对其发泡性能有明显地影响;HDPE6098具有适合发泡的流变特性和相对分子质量分布以及较快的结晶速率,可以获得发泡倍率为17.69倍,泡孔密度为1.30×106个/cm3的样品;而HDPE7000F由于高相对分子质量区域较大,模量较大,导致发泡过程中泡孔生长受到限制,获得的制品较差。

The thermal performance and rheological properties of PE‑HDs were measured by DSC and Hakke rotational rheometer,and then its foaming properties were investigated through the batch foaming experiments.The result indicated that there was a significant effect on the foaming performance of PE‑HD from its crystallization rate and viscoelastic properties.The rheological properties and molecular weight distribution of HDPE6098 were found to be suitable for the foaming process along with its fast crystallization rate.These advantages could help to obtain an expansion ratio of 17.69 times and a cell density of 1.30×106 cell/cm3 for the foamed PE‑HD samples.However,HDPE7000F was found to have a broad high molecular‑weight range and high modulus,leading to a limitation in cell growth during foaming and a poor foamed product.