A continuous flow-through strategy to produce highly isotactic poly(isobutyl vinyl ether) via cationic polymerization

Abstract

Tacticity has a profound effect on the characteristics of synthetic polymers. Herein, a tubular reactor strategy is employed to perform cationic polymerization of isobutyl vinyl ether (IBVE) through a continuous flow process to produce highly stereoselective poly(IBVE). In this approach, two separate n-hexane solutions were prepared, with one containing a catalyst (bis(2,6-diisopropylphenoxy)titanium dichloride) and the other containing an initiator (HCl-IBVE), a monomer (IBVE) and an additive (2,6-di-tert-butyl-4-methylpyridine, DTBMP). Both solutions were merged and mixed in a mixer and flowed into the tubular reactor. The polymerization started in the mixer and continued while flowing through the tubular reactor. Finally, the reaction mixture was collected and the reaction was quenched with ethanol in glassware to afford the poly(IBVE) product. The stereoselectivity of the obtained poly(IBVE) was examined under different polymerization conditions and a meso dyad (m) value of 98% was achieved under the optimum conditions. This work provides a strategy to access highly isotactic poly(IBVE) via a continuous flow process, enabling technical advantages for potential industrial applications.