Radical polymerization by a supramolecular catalyst: cyclodextrin with a RAFT reagent.

ABSTRACT: Supramolecular catalysts have received a great deal of attention because they improve the selectivity and efficiency of reactions. Catalysts with host molecules exhibit specific reaction properties and recognize substrates via host-guest interactions. Here, we examined radical polymerization reactions with a chain transfer agent (CTA) that has ?-cyclodextrin (?-CD) as a host molecule (?-CD-CTA). Prior to the polymerization of N,N-dimethylacrylamide (DMA), we investigated the complex formation of ?-CD with DMA. Single X-ray analysis demonstrated that ?-CD includes DMA inside its cavity. When DMA was polymerized in the presence of ?-CD-CTA using 2,2'-azobis[2-(2-imidazolin-2-yl)propane dihydrochloride (VA-044) as an initiator in an aqueous solution, poly(DMA) was obtained in good yield and with narrow molecular weight distribution. In contrast, the polymerization of DMA without ?-CD-CTA produced more widely distributed polymers. In the presence of 1,6-hexanediol (C₆ diol) which works as a competitive molecule by being included in the ?-CD cavity, the reaction yield was lower than that without C₆ diol.

SUBMITTER: Koyanagi K 

PROVIDER: S-EPMC5238571 | biostudies-literature | 2016

REPOSITORIES: biostudies-literature