Formation and dichroism of poly(vinyl alcohol)–iodine complex in photocurable film

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-I 5 À 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.

Effects of Plasticizing on Mechanical and Viscous Characteristics of Poly(vinyl alcohol): A Comparative Study between Glycerol and Diethanolamine

“…Poly(vinyl alcohol) (PVA) films have been widely utilized in optical devices as polarizers [1] for thin film transistor liquid crystal displays (TFT-LCDs) [2,3] because of their excellent transparency, DOI: 10.1002/mame.202300090 low polarity, and tight complexation, [4,5] achieved through iodine dyeing and highorientation stretching. [5] The universal steps for preparing PVA films include solvation, coating, stretching for tensile orientation, iodinated dyeing, [6] and so on, in which the viscosity [7] of PVA plays a crucial role, particularly for PVA with a high degree of polymerization. [8,9] Entanglement of the segments [9,10] and intermolecular hydrogen bonds within the PVA backbones [11] are obstacles in achieving homogeneous solutions [12][13][14] and advanced mechanical characteristics.…”

Formation Behavior of Polyiodine Complex in Photocrosslinked Polyvinyl Alcohol Fiber Spun by Electrospinning Method

“…The photo-alignment by using PVA-SbQ is one of the methods arranging the polyiodine complex in the oriented PVA chain. It has also been reported that PVA-SbQ improves water resistance by photo-crosslinking [18] and promotes formation of PVA-iodine complex during boric acid treatment [19]. In the electrospinning method, a high voltage is applied to a nozzle, through which the polymer solution is pumped and sprayed to prepare a fibrous film having a micro-nano size.…”