This study was undertaken to fundamentally understand structure–property relationship of blown films of linear low density polyethylene/low density polyethylene blends over the entire composition range via decoupling orientation effects from their intrinsic properties. Three different low density polyethylene blends with an octene Ziegler–Natta linear low density polyethylene resin were studied. The machine direction tear strengths of blown film of linear low density polyethylene/low density polyethylene blends went through a minimum as the low density polyethylene concentration increased, almost a mirror image of the melt strength curve for these blends. The machine direction tear decreased significantly up to 40% low density polyethylene, much sharper decrease compared to decrease in intrinsic tear suggesting orientation effects dominating the machine direction tear behavior. The decrease in the dart impact and puncture energy was also due to both an increase in the machine direction orientation, and a decrease in the intrinsic toughness due to decrease in the tie chain concentration, as the low density polyethylene content increased.

中文翻译：

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线性低密度聚乙烯/低密度聚乙烯共混物吹塑薄膜结构-性能关系的基本原理

本研究旨在从根本上了解线性低密度聚乙烯/低密度聚乙烯共混物吹塑薄膜在整个组成范围内的结构-性能关系，通过将取向效应与其固有特性解耦。研究了三种不同的低密度聚乙烯与辛烯齐格勒-纳塔线性低密度聚乙烯树脂的共混物。随着低密度聚乙烯浓度的增加，线性低密度聚乙烯/低密度聚乙烯共混物的吹塑薄膜的纵向撕裂强度达到最小值，几乎是这些共混物熔体强度曲线的镜像。纵向撕裂显着降低至 40% 低密度聚乙烯，与固有撕裂的减少相比，减少的幅度要大得多，这表明取向效应主导着纵向撕裂行为。随着低密度聚乙烯含量的增加，落镖冲击和穿刺能量的降低也是由于纵向取向的增加和由于连接链浓度降低而导致的固有韧性降低。