Influence of β-cyclodextrin on the free-radical copolymerization of N-(4-Methylphenyl)maleimide with N-vinylpyrrolidone in water

Abstract

Randomly methylated β-cyclodextrin (me-β-CD) is used to include the hydrophobic monomer N-(4-methylphenyl)maleimide (MPM) (1) yielding the corresponding water-soluble host-guest structure 1a. Free-radical copolymerization of 1a with N-vinylpyrrolidone (NVP) (2) is performed and the reactivity ratios r1 and r2 are determined: 0.24 ± 0.03 (r2) and 1.10 ± 0.05 (r1a). This indicates a preferred incorporation of complexed maleimide into the copolymer chain. In contrast to that, the copolymerization of the uncomplexed monomers 1 and 2 is carried out using organic solvent (DMF/H2O) showing reactivity ratios corresponding to nearly alternating copolymerization (r2 = 0.09 ± 0.02; r1 = 0.34 ± 0.03). © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.