Cyclodextrins in polymer synthesis: free radical polymerisation of cyclodextrin complexes of cyclohexyl and phenyl methacrylate in aqueous medium

The polymerisation mechanism of 2,6-dimethyl-beta-cyclodextrin (Me-2-beta-CD) complexes of phenyl methacrylate (1) and cyclohexyl methacrylate (2) is described. The polymerisation of the complexes 1a and 2a was carried out in water with potassium peroxodisulfate/potassium hydrogensulfite as initiator. The unthreading of the Me-2-beta-CD during the polymerisation led to water-insoluble poly(phenyl methacrylate) (1b) and poly(cyclohexyl methacrylate) (2b). By comparison, analogously prepared polymers from uncomplexed monomers 1 and 2 in homogeneous organic solvent (THF) with AIBN as radical initiator showed significantly lower viscosities and were obtained in lower yields in both cases.