POLARIZATION CHARACTERISTICS OF POLY(VINYL ALCOHOL) FILMS CONTAINING METAL IODIDE

The polarization properties of iodine complex layer deposited by oxida tion of poly(vinyl alcohol) (PVA) containing metal iodide were investi gated. Heat-resistant polarizing films with high polarization efficien cy were produced by oxidizing and stretching the PVA containing metal iodide. The results indicate that i) the polarization efficiency of a polarizing film prepared by oxidation of a PVA film containing 1 mmol or more of potassium iodide (KI)/g PVA at 0 degrees C for 120 s in a 1 0 wt.-% aqueous solution of H2O2 and a degree of stretching of 400% is high, ii) the heat resistance of the polarizing film in this experime nt is higher than that of a filter prepared from a commercial PVA film .