Electron transfer polymers. XXIII. Interactions of the quinhydrone type in polyvinylhydroquinone solutions

• Published in: Journal of polymer science. Part A. General papers 1964-10, Vol.2 (10), p.4647-4659
• Main Authors: Kamogawa, Hiroyoshi, Giza, Yueh-Hua Chen, Cassidy, Harold G.
• Format: Article
• Language: English
• ISSN: 0449-2951; 1542-6246
• DOI: 10.1002/pol.1964.100021031

An investigation was made of the pink‐orange color that reaches maximum intensity at the midpoint of the titration of homopolymers of vinylhydroquinone. It was shown that during oxidative titration the hydroquinone absorption at 295 mμ decreases in intensity while quinone absorption at 254 mμ, increases. At the midpoint of the titration absorption at approximately 455 mμ, the pink color, reaches its maximum intensity, with relatively low extinction coefficient. The position of the maxima does not change with extent of oxidation; the specific extinction coefficient is independent of concentration and degree of polymerization, but somewhat dependent on the nature of the solvent. When the functional groups were somewhat separated along the chain by copolymerization with an alternating comonomer, styrene, α‐methylstyrene, or acrylamide, there was no appreciable shift in the ultraviolet absorption peaks with oxidation, but in the visible region the intensity at 455 mμ was greatly decreased, compared with homopolymer, at all degrees of oxidation around the midpoint. Analysis of the spectroscopic data led to the conclusion that the number of quinhydronelike interactions is low relative to the number of groups that are not interacting.