Supplementary Figures from Chemoselective Lewis pair polymerization of renewable multivinyl-functionalized γ-butyrolactones
2017-06-16T14:35:53Z (GMT) by
Multivinyl-functionalized γ-butyrolactones, γ-vinyl-γ-methyl-α-methylene-γ-butyrolactone (γVMMBL) and γ-allyl-γ-methyl-α-methylene-γ-butyrolactone (γAMMBL), have been synthesized from biorenewable ethyl levulinate and effectively polymerized by Lewis pairs consisting of an organic N-heterocyclic carbene Lewis base and a strong organo-Lewis acid E(C6F5)3 (E = Al, B). This Lewis pair polymerization is quantitatively chemoselective, proceeds exclusively via polyaddition across the conjugated α-methylene double bond without participation of the γ-vinyl or γ-allyl double bond, and produces high molecular weight functionalized polymers with unimodal molecular weight distributions. The Al-based Lewis pair produces the polymer with approximately 5.5 times higher molecular weight than that by the B-based Lewis pair. The resulting vinyl-functionalized polymers are soluble in common organic solvents and stable at room temperature, and can be thermally cured into crosslinked materials.