Complexes of Amphiphilic Molecular Brushes with a Polyimide Backbone with Poly- N -Vinylamides in Selective Solvents

The interaction of a molecular brush consisting of a polyimide backbone and luminescence-labeled poly(methacrylic acid) side chains with poly- N -vinylamides (poly- N -vinylpyrrolidone and poly- N -vinylcaprolactam) with different molecular weights is studied via polarized luminescence under stationary excitation in organic solvents with different thermodynamic qualities in relation to the chain blocks of the polymers, namely, selective (methanol) and common (dimethylformamide). The decrease in the mobility of the grafted poly(methacrylic acid) chains with the growth in the molecular weight of poly- N -vinylamide observed in both selective and common solvents gives evidence of the transition from a “loose” structure to a more compact structure of the interpolymer complex. It is shown on the basis of the analysis of the nanosecond relaxation times characterizing the mobility of the sections of the grafted poly(methacrylic acid) chains and reflecting the change in the intra- and intermolecular interactions that the formation of interpolymer complexes in dimethylformamide leads to a looser structure.