超声辐照对HDPE分子量分布及拉伸行为的影响

Effects of Ultrasonic Irradiation on Molecular Weight Distribution and Tensile Behavior of HDPE

研究了低挤出速率下，超声辐照对ＨＤＰＥ 分子量、分子量分布及拉伸行为的影响。结果表明，挤出机转速５ｒ／ ｍｉｎ 时，超声功率大于２００ Ｗ 会使熔体表观粘度急剧下降，挤出物分子量分布曲线出现双峰并向低分子量方向移动，样品拉伸应力应变过程中的应力硬化现象消失，拉伸强度和断裂伸长率降低，说明高强度的超声辐照作用会使ＨＤＰＥ 部分降解，分子结构发生永久性的变化。

s Effects of ultrasonic irradiation on structure and properties of HDPE at low extrusion speed (5rpm) were studied.The results showed that high intensity ultrasonic irradiation made the viscosity,molecular weight,tensile strength and elongation at break of HDPE decreased Stress hardening phenomenon of HDPE during extension also disappeared gradually as ultrasonic irradiation power rised,indicating that mechanodegradation and permanent changes in structure of HDPE occurreed.