Poly (4-vinylpyridine)/cupric salt complexes: spectroscopic and thermal properties

Copper(II)-containing poly(4-vinylpyridine)(P4VP) blends which form coordination complexes have been investigated through spectroscopy and thermal analysis. The complexes were obtained by mixing the polymer with copper sulfate, copper chloride or copper thiocyanate in a common solvent. Thermal analysis via differential scanning calorimetry (DSC) was used to evaluate the glass transition of the amorphous polymer-rich phase showing the phase behavior of these binary mixtures at the macroscopic level. Infrared and Raman spectroscopies were used in indirect detection mode to probe microenvironmental factors that influence mixing. The nitrogen ligand of the P4VP is perturbed in blends with Cu(II) ions and anion complexation, due to the accessible structure of the nitrogen atom in the macromolecule chain. The anion influence is strong and the evaluation of the chloride, sulfate and thiocyanate polymer complexes shows distinct thermal properties which suggest different conformations due to coordination effects. (C) 2004 Elsevier Ltd. All rights reserved.