Abstract

Rheological, molecular, thermal, and mechanical properties of binary blends based on bimodal high-density polyethylene (HDPE; ethylene–1-hexene copolymer) and unimodal linear low-density polyethylene (LLDPE; ethylene–1-butene–1-hexene terpolymer) were studied. Six blends with different HDPE/LLDPE weight ratios, 80/20, 70/30, 60/40, 50/50, 40/60, and 20/80, were prepared by blending in a double-worm extruder. The correlation of the rheological properties of the blends, analyzed by the capillary and rotation methods, with the melt flow index and molecular characteristics was demonstrated. LLDPE with increased flowability (MFI = 3 g/10 min) as a polymer additive is an effective plasticizer allowing control of the melt viscosity in a wide range and choice of the optimum target value of the melt flow index of the blend. The activation energy of the melt flow was calculated, and the relationship between this quantity and the content of short-chain branchings in polyethylene blends was revealed. The blends obtained are homogeneous, but an increase in the content of LLDPE in HDPE leads to a change in the polyethylene structure, which is confirmed by a decrease in the crystallinity and in the lamella thickness. The strength values at the yield point and at break decrease with an increase in the fraction of LLDPE in HDPE. Changes in the properties of these blends in their processing into a film by flat-die extrusion were studied.

中文翻译：

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基于高密度聚乙烯和线性低密度聚乙烯的二元化合物的结构，流变和力学性能

摘要

基于双峰高密度聚乙烯（HDPE;乙烯-1-己烯共聚物）和单峰线性低密度聚乙烯（LLDPE;乙烯-1-丁烯-1-己三元共聚物）的二元共混物的流变，分子，热和机械性能被研究了。通过在双蜗杆挤出机中共混来制备六种具有不同HDPE / LLDPE重量比（80 / 20、70 / 30、60 / 40、50 / 50、40 / 60和20/80）的共混物。通过毛细管法和旋转法分析了共混物的流变性能与熔体流动指数和分子特性之间的关系。具有提高的流动性（MFI = 3 g / 10分钟）作为聚合物添加剂的LLDPE是一种有效的增塑剂，可以在较大范围内控制熔体粘度，并可以选择共混物熔体流动指数的最佳目标值。计算了熔体流动的活化能，揭示了该数量与聚乙烯共混物中短链支链含量之间的关系。所获得的共混物是均质的，但是HDPE中LLDPE含量的增加导致聚乙烯结构的改变，这由结晶度和薄片厚度的降低证实。HDPE中LLDPE分数的增加会导致屈服点和断裂处的强度值降低。研究了这些共混物在通过平模挤出加工成膜时的性能变化。但是，HDPE中LLDPE含量的增加会导致聚乙烯结构的改变，这可以通过结晶度和薄片厚度的降低来证实。HDPE中LLDPE分数的增加会导致屈服点和断裂处的强度值降低。研究了这些共混物在通过平模挤出加工成膜时的性能变化。但是，HDPE中LLDPE含量的增加会导致聚乙烯结构的改变，这可以通过结晶度和薄片厚度的降低来证实。HDPE中LLDPE分数的增加会导致屈服点和断裂处的强度值降低。研究了这些共混物在通过平模挤出加工成膜时的性能变化。