Preparation and Study of Structural, Optical and Electrical Properties of the Composite Films [PVA-PEO-MnCl2.4H2O]

Abstract

In the present paper, pure polymeric blend film [PVA-PEO] and the polymeric blend films reinforced by MnCl₂.4H₂O  salt with different weight ratios (10, 20, 30, 40, 50 wt %) have been prepared  by using the solution casting method. The effects of weight ratio of salt on structural properties for all reinforced polymeric blends  films were studied.  FTIR spectra were used to establish  the interaction between the polymer (PVA) and the polymer (PEO) reinforced by MnCl₂.4H₂O salt, which causes some changes in the vibration modes and the position of the bonds. All inrestigated  samples exhibited  broad  bonds at  around  (3310 cm^-1). The results showed the asymmetric vibration of  O-H group in the polymers matrix.  The peaks around (2880 cm^-1) can be attributed to the presence of C- H stretching vibration group. The C=C stretching vibration appears in the bonds at (1955 cm^-1). The peak at (1096 cm^-1) for all reinforced films is attributed to the stretching mode of C-O-C stretching. There is a shift of out-of-plane rings C-H bending vibration from 961.2 to 955 cm^-1. These indicate the chemical interactions of MnCl₂.4H₂O salt with the polymeric blend [PVA-PEO]. The two strong bonds observed around (1471 cm^-1 and 844 cm^-1) are assigned to the bending and stretching vibration of the CH₂ group, respectively. The change in the spectral intensities of polymeric blend [PVA-PEO] involves a shift in some bonds due to the MnCl₂.4H₂O salt  addition.   The effects of weight ratio of salt  on optical properties for all reinforced polymeric blends films  were studied,  as the transmittance and absorbance  spectra  were  recorded within the range of wavelengths (190-1100) nm, and it was found that the energy gap value decreases with an increase of the  added  salt’s weight ratio. Results showed that the indirect electronic transitions are allowed.  Effects of salt’s weight ratio on electrical (dielectrical) properties for all reinforced polymeric blends films  were studied,  and the practical results showed a decrease in the dielectric constant (ε΄) with an increase in frequency for all polymeric blends films, while the practical results also showed an increase in the alternating electrical conductivity (σ_a.c)  with increasing frequency for all polymeric blends films, as well as an increase in both the dielectric constant and  alternating electrical conductivity with an increase in the added  salt’s weight ratio at same frequency.