writer：Handing Wang，Yu Li，Wei Li，Yuming Chen， Binbo Jiang，Jingdai Wang，Yongrong Yang
keywords：Structure–property relationship，Biaxial stretchable property，Crystallization，Fractionation
source：期刊
Issue time：2022年

The market capacity of biaxially oriented polyethylene (BOPE) films increases rapidly (> 15% annually) due to the extremely excellent optical and economical feature, which meets the carbon neutrality requirements. Thus, the polyethylene resins selection is critical for BOPE films production and usage. In this contribution, we investigated the effects of molecular weight, branch chain distribution, melting behaviors, and crystallization behaviors of LLDPE resins on their biaxial stretchable properties for establishing the microstructure-mechanical property relationship and screening criteria for tenter-frame biaxially oriented polyethylene (TF-BOPE) resins. It was observed that a wider biaxial stretchable temperature range and a lower biaxial stretching temperature were required to facilitate the biaxial stretching process. A suitable molecular weight, a moderate crystallization rate, a thinner lamellae thickness, and a lower initial melting temperature are beneficial for the film stretch and production. Besides, A uniform lamellae thickness distribution in this molecular weight interval was conducive to expanding the biaxial stretch temperature range and reducing the films breakage.