COMPETITIVE COMPLEX-FORMATION IN THE SYSTEM POLY(METHACRYLIC ACID)-MONOSUBSTITUTED POLY(ETHYLENE GLYCOL)-POLY(N-VINYLPYRROLIDONE) [POLY(ETHYLENE GLYCOL)]

Competitive complex formation in aqueous solutions containing poly(methacrylic acid) (PMA), monosubstituted poly(ethylene glycol) (PEG*), and poly(N-vinylpyrrolidone) (PVP) or poly(ethylene glycol) was studied with UV spectroscopy. Using UV spectroscopy to study complex formation with PEG*, which contains a hydrophobic chromophoric group, rests on the fact that, when the chromophoric group in PEG* leaves aqueous environment and appears in hydrophobic domains of a (PMA PEG*) polycomplex, the UV spectrum of this group shifts to longer wavelengths (bathochromic shift). The suggested approach using a polymeric competitor containing a hydrophobic chromophore as a reference (PEG* in the case under consideration) may be helpful when direct comparison of the competition between polymer reagents cannot be performed.