Easy Access to Ultrahigh-Molecular Weight Poly(1,3-dioxolane) by Rare Earth Triflates

Abstract

Ultrahigh-molecular weight (UHMW) polymers are promising with outstanding properties while challenging to obtain, particularly via cationic ring-opening polymerization (CROP), where chain transfer side reactions and polymerization− depolymerization equilibria are inevitable. Previous reports on UHMW polymer synthesis by CROP involved strict purification and addition of proton traps to remove trace water. In the contribution, heterogeneous CROP of 1,3-dioxolane (DO) catalyzed by rare earth triflates with water content up to 17,000 ppm produces UHMW poly(1,3-dioxolane)s (PDOs) with M w over 1,800 kg/mol because moisture bonded in the heterogeneous catalyst does not influence the polymerization. The robust polymerization is rapid within minutes at room temperature. Density functional theory calculation reveals relatively slow initiation and fast propagation, which explains the generation of UHMW PDO. The UHMW PDO exhibits a high Izod impact strength up to 296 J/m, tougher than commercial UHMW polyethylene. The contribution provides facile access to UHMW PDO, a degradable and recyclable plastic promising to be applied in impact-resisting materials.