Separation of amorphous and semicrystalline parts of <scp>LLDPE</scp> with high‐temperature interactive liquid chromatography

Linear low-density polyethylene (LLDPE) materials may contain components, which are soluble at room temperature. These influence physical properties or raise concerns for end-users and regulatory bodies because LLDPE is widely used food packaging. Due to the nonpolar amorphous nature of temperature part LLDPE, its molecular characterization with common methods polyolefin analysis, such as Temperature Rising Elution Fractionation (TREF), Crystallization (CRYSTAF), Differential Scanning Calorimetry (DSC), has proven be very challenging. Separation well semicrystalline part, is, however, realizable high-temperature liquid chromatography (HT-LC), demonstrated first time in this work. This technique enables evaluate chemical composition distribution room-temperature solubles non-solubles samples. It was found that synthesized metallocene catalysts contained only a small amount material. In contrast, prepared Ziegler-Natta up 14 wt.% copolymer. The latter temperature, had weight-average molar mass ranging from 60 200 kg/mol, about 10 mol% more 1-olefin than non-soluble LLDPE.