相容剂对HDPE/竹粉复合材料挤出流动性的影响

Influences of Compatilizers on Melt Extrusion of HDPE/Bamboo Flour Composites

采用旋转流变仪研究了高密度聚乙烯(HDPE)/竹粉复合体系分别经树状聚合物(PAMAM)、乙烯-甲基丙烯酸甲酯(EMA)这两种相容剂处理及未处理后熔体的动态黏弹性,并进一步以转矩流变仪毛细管挤出平台研究了熔体的挤出流动特性。结果表明,竹粉粒子的加入增加了熔体的黏弹性,体系松弛时间更长,熔体流动性差,挤出易熔体破裂。加入相容剂后,熔体的模量和黏度均降低,加工性能有所改善,而加入PAMAM后,熔体模量、黏度更低,表现出更好的加工流动性,PAMAM的球状结构使竹粉粒子之间、竹粉粒子与HDPE分子链间的相互作用减弱,起到分子链间的滑动轴承的作用,很好地改善熔体的流动性,对挤出物熔体破裂的改善程度更加显著。

High density polyethylene （HDPE）/bamboo flour composite system was treated with dendritic polymers （ PAMAM ） and ethylene-methyl methacrylate （ EMA ） respectively, and the dynamic viscoelasticity of the treated and untreated composite system were studied by rheometer. The melt extrusion flow characteristics were further investigated by using capillary extrusion platform of torque rheometer. The results demonstrated that, with the addition of bamboo flour particles, viscoelastic properties of the melt increased, the relaxation time became longer, and the fluidity of the melt was so poor as to bring melt fracture. The adding compatilizers reduced the viscosity and modulus of the melt, improving the processability. And the addition of PAMAM made the viscosity and modulus of the melt lower, showing more better flowability. The globular structures of the dendrimers made the interaction between bamboo flour particles, bamboo flour particles and molecular chains of HDPE matrix weaken, which acted as the sliding bearing of intermolecular chains, so the mobility in extruder and the melt fracture of the extruded melt were well improved.