The kinetics of chromic acid oxidation of poly(vinyl alcohol) (PVA), a synthetic polymer, in perchlorate media at a constant ionic strength of 1.0 mol dm−3 has been studied spectrophotometrically. A first-order reaction in chromic acid and a fractional or

Interpolymer adduct formation between polycarboxylic acids and poly(N-vinylpyrrolidone) (PVP) was investigated using covalently bound protoporphyrin IX (PPIX) with macromolecules as fluorophore. The fluorophore, PPIX is present in very low concentration and the change in the fluorescence intensity and the lifetimes of polymer bound PPIX is interpreted to characterize the interpolymer complex formation. The polycarboxylic acid used are polyacrylic acid (PAA) and polymethacrylic acid (PMAA). Fluorescence decay curves of polymer bound PPIX are fitted well to a biexponential function which is suggested to be due to the presence of fluorophore in different environments of the macromolecule in aqueous solution. The fluorescence intensities and the lifetimes of the fluorophore in poly(acrylic acid-co-protoporphyrin IX) poly(AA-co-PPIX) and poly(methacrylic acid-co-protoporphyrin IX) poly(MAA-co-PPIX) increase significantly on complexation with PVP due to the displacement of water molecules in the vicinity of PPIX. The fluorescence intensity and the lifetime of PPIX bound to poly(N-vinylpyrrolidone-co-protoporphyrin IX) poly(VP-co-PPIX) decrease on the addition of PAA or PMAA signifying that the local environment of PPIX bound to PVP is more hydrophilic. The contrasting behaviour of the same polymer adduct with respect to the site of the fluorophore is interpreted to be due to the solvent structure which determines the environment of the fluorophore. The study for the first time throws light on the effect of the solvated macromolecule in determining the polymer aggregation and the site preference for any host molecule. These types of preferential environment for a host molecule are important in drug design and other biological processes.