Photocrosslinking Behavior of a Highly Concentrated Aqueous Solution of Poly (vinyl alcohol) with Pendent Styrylpyridinium

Abstract

Photoinduced gelation behavior of some highly concentrated aqueous solutions of poly (vinyl alcohol) (PVA) with pendent styrylpyridinium (SbQ) was studied. The quantitative determination of the crosslinking degree of PVA with pendent SbQ (PVA-SbQ) was made by means of UV and NMR spectroscopy. The quantum efficiency for the photodimerization of pendent SbQ in an aqueous solution state decreased monotonously as the crosslinking degree increased. It was estimated to be 0.4 at 50% of the crosslinking degree. This value was higher than that inthe thin film state. The photocrosslinking rate of PVA-SbQ in aqueous solution was dependent on the molecular weight of PVA, but independent of the amount of pendent SbQ.