挤出微交联反应提高聚丙烯熔体强度的研究

Improvement of Melt Strength of Polypropylene by Micro-cross-linking through Reactive Extrusion

使用单螺杆挤出机和反应挤出机研究了聚丙烯(PP)在引发剂与交联剂作用下的微交联反应,应用在线熔体强度仪等方法检测了产物的熔体强度变化情况,制备出了能够保持较高流动性的高熔体强度聚丙烯。试验表明,单螺杆挤出机的使用效果优于反应挤出机,同时在试验配方范围熔体强度呈现先升高后降低的趋势。最佳工艺和配方为:挤出温度160,180,190,190,180℃、螺杆转速50~60r/min;使用过氧化二异丙苯(DCP)为引发剂,质量分数0.03%~0.04%;二乙烯基苯(DVB)为交联剂质量分数0.30%~0.50%。该条件下可以制备出表面光洁、凝胶质量分数低于0.51%的高熔体强度聚丙烯。

The micro-crosslink reaction of polypropylene （PP） using initiator and cross-linker was studied with single-screw extruder and reactive extruder respectively. The melt strength of reactive product was measured with online melt strength tester and other method, and high melt strength PP with high fluidity was prepared. The results show that the single-screw extru-der is better than the reactive extruder for the reaction. The melt strength in the recipe range increased first and then decreased. The melt strength of PP could be significantly improved at extruiton temperature of 160,180,190,190,180℃,and screw speed of 50-60 r/min with DCP and DVB. The optimal contents of DVB and DCP are 0.3-0.5% and 0. 03-0. 04% repectively, and cross-linked gel in the high melt strength PP is less than 0.51%.