硬脂酸钙/硅酮粉改性PE-UHMW/PE-HD共混物的制备  

Preparation of PE-UHMW/PE-HD blends modified with calcium stearate/silicone powder

作　　者：刘杰[1] 韩宁 秦升学[1] 张弘斌[1] 周海萍 LIU Jie;HAN Ning;QIN Shengxue;ZHANG Hongbin;ZHOU Haiping(College of Mechanical and Electrical Engineering,Shandong University of Science and Technology,Qingdao 266590,China)

机构地区：[1]山东科技大学机械电子工程学院,山东青岛266590

出　　处：《工程塑料应用》2024年第11期45-49,共5页Engineering Plastics Application

基　　金：山东省重点研发计划项目(2022CXGC020207)。

摘　　要：超高分子量聚乙烯(PE-UHMW)与高密度聚乙烯(PE-HD)熔融共混,可提高PE-UHMW熔体加工性能,但其工业化生产效率仍然较低,无法满足熔体纺丝工业生产的需求。针对此问题,通过双螺杆挤出机熔融共混与单螺杆挤出机挤出实验,研究了硬脂酸钙(CaSt_(2))、硅酮粉及其复合助剂对质量配比为60∶40的PE-UHMW/PE-HD共混物加工流动性及拉伸性能的影响。加工扭矩与初生丝表面状态结果表明,CaSt_(2)、硅酮粉及其复合助剂均能降低加工扭矩,提高熔体挤出稳定性。黏流活化能结果表明这两种添加剂具有内润滑效果。在高剪切速率下,CaSt_(2)表现出较强的外润滑效果,能进一步降低加工扭矩,提高熔体挤出的稳定性。CaSt_(2)与硅酮粉协同使用,可以进一步提高助剂内润滑作用,降低挤出扭矩并提高挤出稳定性。差式扫描量热分析表明,改性剂可促进共混物结晶,从而使材料拉伸强度提高。研究结果表明,质量分数0.5%CaSt_(2)和0.5%硅酮粉复合改性剂表现出内外润滑的协同作用,与未改性共混物相比,协同改性使PE-UHMW/PE-HD共混物挤出合格初生丝最高螺杆转速从5 r/min升高到20 r/min,加工扭矩降低21.4%,拉伸强度提高11.9%。Ultra-high molecular weight polyethylene(PE-UHMW)blended with high-density polyethylene(PE-HD)can improve the melt processing performance of PE-UHMW,but the efficiency of industrial production remains low,unable to meet the demands of melt spinning in industrial production.To address this issue,the effects of calcium stearate(CaSt_(2)),silicone powder,and their composite additives on the processing flowability and tensile properties of a PE-UHMW/PE-HD blend with a mass ratio of 60∶40 were investigated,using experiments with a twin-screw extruder for melt blending and a single-screw extruder for extrusion.Results regarding processing torque and the surface condition of the as-spun fibers indicate that CaSt_(2),silicone powder,and their composite additives can reduce processing torque and enhance the stability of melt extrusion.The results of flow activation energy indicate that these two additives exhibite internal lubrication effects.At high shear rates,CaSt_(2) demonstrates a strong external lubrication effect,further reducing processing torque and improving melt extrusion stability.The combined use of CaSt_(2) and silicone powder can enhance the internal lubrication effect of the additives,lowering extrusion torque and improving extrusion stability.Differential scanning calorimetry analysis shows that the modifiers can promote the crystallization of the blend,thereby increasing the material's tensile strength.The study results indicate that the composite modifier consisting of 0.5 wt%CaSt_(2) and 0.5 wt%silicone powder exhibits a synergistic effect of internal and external lubrication.Compared to the unmodified blend,the synergistic modification allows the maximum screw speed for producing qualified as-spun fibers of the PE-UHMW/PE-HD blend to increase from 5 r/min to 20 r/min,with a 21.4%reduction in processing torque and an 11.9%increase in tensile strength.

关 键 词：超高分子量聚乙烯 高密度聚乙烯 复合助剂 熔体加工性能 拉伸强度 

分 类 号：TQ342[化学工程—化纤工业]