Frustrated Lewis Pairs Mediated Polymerization Of Polar Olefin Monomers And The Functionalization

Polar olefin polymers, including poly(methyl methacrylate)(PMMA), can effectively improve the viscosity, toughness, and interfacial properity of polyolefins, owing to the introduction of polar group in the main chain of polymers, significantly broadening their commerical applictions. They are usually achieved by anionic polymerization or coordination polymerization. Extraodinary advancements have been achieved in the employment of frustrated Lewis pairs (FLPs) in polymerization of polar olefin monomers, which can avoid the side effects of anionic polymerization and lots of expensive additives of coordination polymerization. In this paper, Frustrated Lewis Pairs were used as catalysts for the polymerization of methacrylate monomers and further study of the functionallization of the resultant polymers.1. Frustrated Lewis Pairs were applied as catalysts in in homopolymerizing methacrylate monomers such as VMA, AMA and PgMA, as well as copolymerizing MMA with VMA or HEMA-TMS. This method has advantages of raw materials readily available simple operation, mild reaction conditions and the resultant copolymers with high molecular weight, narrow molecular weight distribution and syndiotacticity-enriched structure. The F-R law computational method was applied to investigate the reactivity ratios of different monomers during the copolymerization. The reactivity ratios (rMMA=0.71,rHEMA-TMS=0.69; rAMA=0.92, rPgMA=0.47) are less than 1, indicating the irregular structure of the copolymers.2. The novel PPgMA appended with side alkyne groups was synthesized and transformed into ethyl azidoacetate functionalized polymer through the Cu(I)-catalyzed Huisgen 1,3-dipolarcycloaddition reaction. The resulted P(MMA-co-VMA)-OH could react with Boc-(L, D)-Phe to obtain the chiral comb P(MMA-co-VMA)-g-Boc-(L,D)-Phe.3. The resulted P(MMA-co-VMA)-OH could be directly used as macroinitiators for initiate ring-opening polymerization of ε-caprolactone with Sn(Oct)2 as catalyst, affording the P(MMA-co-VMA)-g-PcL semicrystalline polymer with a melting temperature (Tm=55℃). Moreover, the P(MMA-co-VMA)-OH could also initiate the ring-opening polymerization of lactide using DBU as catalyst, affording the P(MMA-co-VMA)-g-PLA graft copolymers with a melting temperature (Tm=192℃).