Influence of Molecular Structure on Crystallization Kinetics and Performance of Polyethylene of Raised Temperature Resistance

Two copolymer polyethylenes of raised temperature resistance (PE-RT) were used to analyze their basic properties and molecular structure, including their basic physical properties, molecular weight and distribution, molecular chain structure, and aggregation structure of the product; the crystallization kinetics and other properties differences are also discussed. The results showed that the basic physical properties of the two resins were similar, but there were still some differences in molecular structure. The molecular weight of PE-RT-1 was slightly lower in the range of 500,000–1,000,000 molecular weight, and slightly higher in the range of <500,000 molecular weight than PE-RT-2. The crystallization capacity of the crystallizable part of PE-RT-2 was slightly better than that of PE-RT-1. The comonomer (1-butene) content and polymer branching degree of PE-RT-2 were higher than those of PE-RT-1. The crystallinity of PE-RT-1 products was higher than that of PE-RT-2, and the lattice structure of PE-RT-1 was more complete and had good heat resistance. In addition, the butene content of PE-RT-2 with high molecular weight was higher than those of PE-RT-1, which was more conducive to the generation of tie molecules.