热塑性聚合物熔体流动速率测定

Determination of thermoplastic polymer melt flow rate

高聚物的结晶过程、结晶性高聚物拉伸时的细颈现象、熔体的挤出胀大现象和不稳定流动现象,是高分子物理课程中的重要知识点,"热塑性聚合物熔体流动速率的测定"是高分子物理实验课程中的典型实验。通过选用结晶性聚合物PE,在完成该实验教学基础上,利用切样前和切样后的余料,观察了高聚物的结晶现象、结晶性高聚物拉伸时的细颈化现象、熔体的挤出胀大现象和不稳定流动现象。现象的观察与测量直观,有助于学生加深对课堂授课内容的理解。

The crystallization process of polymer, the necking phenomena during tensile test of crystal polymer, the melt extrusion swell phenomenon and the melt flow instability phenomenon are the key knowledge points in Polymer Physics course. Meanwhile, ＂The determination of thermoplastic polymer melt flow rate＂ is a classic experiment in Polymer Physics Experiment course. This paper takes PE as a common crystalline polymer material, which is chosen to complete the teaching experiment of the determination of thermoplastic polymer melt flow rate. On the basis of the melt flow rate measurement, using the remaining barrel material, the crystallization process, necking phenomena, melt extrusion swell phenomenon and melt flow instability phenomenon could also he observed. The above phenomenon observation and measurement, which are both intuitive and students＇ personal experience, can help students understand the Polymer Physics classroom teaching knowledge.