Thermal Fractionation of Polyolefins: Brief History, New Developments and Future Perspective

For semi-crystalline polymer materials, the difference in chain structure often leads to different physical properties; therefore, in-depth analysis of the chain structure is of great significance. With the continuous development of advanced instruments, many research means have emerged to characterize the structure of molecular chains. Among them, fractionation techniques provide effectively structural information on inter- and intra-molecular comonomer distribution, branching degree, and sequence length, etc. This work briefly presents the history of developments of various classical fractionation means such as temperature-rising elution fractionation, stepwise crystallization and successive self-nucleation and annealing, while focusing on the present and future of their applications.