PE-LD棚膜专用树脂的流变性能研究

选取了几种典型的低密度聚乙烯（PE-LD）棚膜专用树脂，综合转矩流变仪、毛细管流变仪、熔体拉伸流变仪、旋转流变仪等多种流变测量技术研究了其剪切和拉伸流变性能。结果表明，2100和1810D树脂的支化程度更高，加工负荷低，熔体剪切敏感性更高，树脂的加工性能更好；同时，2100树脂的熔体强度更高，应变硬化效应明显，有利于膜泡稳定性；动态流变试验结果显示，长松弛时间分子链提供了熔体强度与应变硬化，宽分布松弛谱赋予了树脂的良好加工性能，2100与1810D树脂的综合性能更佳。

Study on Rheological Behaviors of PE-LD Resins Used for Greenhouse

The shear and extensional rheological properties of several types of PE-LD resins specially used for greenhouse were investigated intensively by using torque rheometer, capillary rheometer, melt extension rheometer and rotating rheometer. The results indicated that 2100-type and 1810D-type resins had a higher branching degree, lower processing load, higher shear sensitivity and better processability then the others. As for the 2100-type resin, its higher melt strength and more obvious strain hardening effect favored the stability of film bubble. The dynamic rheological experimental results showed that the molecular chain with long relaxation time gave melt strength and strain hardening, and the wide distribution relaxation spectrum provided good processing performance. Summarily, the 2100-type and 1810D-type resins exhibited optimum comprehensive performance among the selected resins.