高熔体强度聚丙烯的挤出发泡行为

Extrusion Foaming Behavior of High Melt Strength Polypropylene

研究了高熔体强度聚丙烯为发泡树脂的挤出发泡行为,分别采用聚合物流变工作站、偏光显微镜、扫描电镜等考察了挤出配方和工艺对发泡体系流变性能及发泡性能的影响。研究发现,高熔体聚丙烯的熔体黏度随发泡剂用量、螺杆温度、螺杆转速的提高而降低,聚丙烯发泡制品的泡孔形态、泡孔密度和尺寸在螺杆温度为(185±3)℃,模头温度为(153±1)℃,螺杆转速为(19±2)r/min,自制发泡剂体系用量为4%时最佳,泡孔尺寸均匀且泡孔密度可以达到每立方厘米2.65×1013个以上,此时发泡倍率为9.6倍。

Extrusion foaming behavior of high melt strength polypropylene（PP） was studied.The effect of the formulation and extrusion process on rheology and foaming properties was investigated by polymer rheology workstations,polarized light microscopy,scanning electron microscope（SEM）.It is found that viscosity of high melt strength PP is decreased when foaming agent amount,screw temperature,screw speed are increased,and the morphology,structure and cell size of foaming polypropylene,apparent density of products are the best when the screw is（185±3） ℃,the die temperature is（153±1） ℃,screw speed is（19±2） r/min and the amount of foaming agent is 4%,the cell size is uniform and the expansion ratio is 9.6 times when the cell density can be reached to 2.65×1013 cm3.