“…13,14 Among those cyclic alkenes, norbornene derivatives are one of the most polpular monomers because of the high activity, easy preparation, and easy functionalization. Numerous studies have been done around norbornene derivatives, such as polymerization mechanism, 15,16 the effect of monomer stereochemistry and composition on the ROMP polymerization, [15][16][17][18] the optimization of polymerization conditions, [19][20][21][22][23] the preparation and application of functional polymers based on polynorbornene derivatives. 5,6,[11][12][13][14][24][25][26][27][28][29][30][31] However, linear polymers with ultra-high molecular weight (UHMW) (>10 6 g mol À1 ) were difficulty prepared by ROMP directly owing to the restrictions of monomer stereochemistry, composition, purity, and polymerization conditions.…”