Molecular and Associative Properties of N-Vinylpyrrolidone Copolymers with N-Crotonoylaminocaproic Acid in Dilute Solutions

The random copolymers of N-vinylpyrrolidone and N-crotonoylaminocaproic acid attractive for the modification of drugs are studied by static and dynamic light scattering, viscometry, and sedimentation-diffusion analysis. The content of functional groups in the copolymers is 14.1-27.0 mol %. Analysis is performed in 0.1 N aqueous solutions of sodium acetate and dimethylformamide. The molecular characteristics of the copolymers with various composition are determined. It is shown that supramolecular structures are present in copolymer solutions and their amount depends on copolymer composition; the effect of solvent on the formation of these structures is ascertained.