Formation and dichroism of poly(vinyl alcohol)–iodine complex in photocurable film. (23rd January 2015) - Takahara, Shigeru
Abstract The formation of polyiodine complexes was investigated in a photocurable poly(vinyl alcohol) modified N‐methyl‐4(4′‐formylstyryl)pyridinium methosulfate acetal (PVA‐SbQ), which is a photofunctional group that causes photodimerization. PVA‐SbQ films with polyiodine complexes were prepared to be photocured, iodinated and soaked in a boric acid solution. The formation of PVA–polyiodine complexes was studied during iodinating and while in the boric acid treatment through UV–vis absorption spectrometry, resonance Raman spectrometry and IR absorption spectrometry. As a result, polyiodines were formed in the photocurable PVA‐SbQ films, and the formation of PVA–polyiodine complexes was enhanced by boric acid treatment. It was found that the SbQ‐ratio of PVA‐SbQ affects the formation of PVA–polyiodine complexes. The photocrosslinking by the dimerization of SbQ groups helps to form the PVA–I5− complex during the boric acid treatment. Based on this effect, we demonstrated a unique recording method by the PVA–polyiodine complex formation. The PVA‐SbQ film cured by the irradiation of the liner polarized light showed that dichroism of the PVA–polyiodine complexes formed after iodination. Copyright © 2015 John Wiley & Sons, Ltd.