Spectroscopy and Conductivity Studies of Polyvinyl Alcohol (PVA)/Polypyrrol (Ppy) Nanocomposite with Various Chloride Metals to Improved Properties of the Polymers

Polyvinyl alcoholpolypyrrole (PVA-PPY) nanocomposites with metal chlorides (FeCl3, NiCl2, CuCl2 and ZnCl2) have been synthesized by chemical oxidative polymerization method. These synthesized nanocomposites are characterized by using FTIR, X-Ray Diffraction, Transition Electron Microscope (TEM) and Conductivity measurement. TEM exhibit that all of the composites have uniform sizes and morphologies. The diameter of PVA/PPY nano composite is 58nm when the metals added to the PVA/PPY the diameters becomes smaller. The variation of electrical conductivity (log σ) with 1000/T for PVA/PPY nanocomposite with metal chlorides revealed that the increase in conductivity  at temperature (393K) with added metals can be attributed to the creation of induced charge carriers in PVA/PPY matrix


INTRODUCTION
Crystallization behavior of semi crystalline polymer has been extensively investigated due to their technological and theoretical importance. Diverse semi crystalline polymers such as polyethylene (PE), polypropylene (PP), polyamide, poly (ethylene terephthalate) (PET), and polystyrene (PS), have been adopted to analyze the crystallization behavior of polymeric materials. L Pan et al [1] A vinyl polymer, namely polyvinyl alcohol (PVA) is semi crystalline, water soluble, and low electrical conductivity material. PVA exhibits certain physical properties resulting from crystal-amorphous interfacial effects. Electrical conductivity of PVA can be tailored to a specific requirement by the addition of suitable material. Crystallization behavior of poly (vinyl alcohol) (PVA) has been also studied by several research groups under different experimental conditions because the hydroxyl group containing semi-crystal polymers have been of special interest. H Byun et al [2]. In general, these studies have been conducted using DC electrical conductivity, X-ray different scattering (XRD), Fourier transform infrared spectroscopy (FTIR) and Transition electron microscopy (TEM).
In the present work, the Polyvinyl/ polypyrrole (PVA/PPY) Nan composite with metal chlorides (FeCl 3 , NiCl 2 , CuCl 2 and ZnCl 2 ) have been characterized by using various techniques such as FTIR, XRD, TEM and DC electrical conductivity.
The XRD and TEM are performed in order to confirm the crystallization behavior of PVA/PPY metals Nan composite. In this regard we have made an attempt to study the electrical conductivity of pure PVA, PPY and nanocomposite with metals to know the influence of metals on pure polymer in answering better electrical conductivity.

O S NH
and this reaction mixture was stirred continuously for 3 hours at a constant temperature (5 º C) to obtain polypyrrole. 100ml of PVA solution was mixed with 100ml of PPY solution in 1:1 ratio by volume stirred for 20 minutes at the room temperature in order to get homogenous solution. Finally 0.3 gm of FeCl 3 was added in the mixture and stirred for 12 hours. By repeat the last step with added 0.3 gm of NiCl 2 , CuCl 2 and ZnCl 2 respectively. The obtained product was filtered or center fused and washed thoroughly with methyl followed by distilled water. Nanocomposite was vacuum dried at 60 º -70 º c for 1 h.

MEASUREMENTS
A Fourier transforms infrared (FT-IR) spectrometer (Model Jasco, 300E). The IR spectrometer in KBr medium at room temperature in the region 4000 -400cm -1 . The X-ray diffraction pattern of the sample was measured using (X PERT -PRO -PAnalytical). XRD operating at 30mA and 45kv, using Cuk(alpha), (=1.4506A º ). The diffract gram was recorded in terms of 2θ in the range (0-100) º . The powder of morphology the nanocomposite was investigated by TEM (JEOL JEM. 1010). The nanocomposite powder was prepared by making a suspension from the powder in distilled water. The suspension was centrifuged to collimate the large size particles. To study the electrical conductivity of nanocomposites powder it should be pressed in form of circular pellets with 13mm diameter and 1-3mm in thickness by applying pressure 10 tons/cm 2 . The pellets of PVA/PPY and its metal nanocomposites were coated with silver paste on either side. The DC electrical conductivity of pure PVA/PPY and metal nanocomposite was investigated over the temperature range from room temperature to about 393K to study the effect of metals on the D.C electrical properties of PVA/PPY. The electrical conductivity  was calculated using:

FTIR Spectra
The FTIR spectra of synthesized PVA/PPY and PVA/PPY nanocomposite with (FeCl 3 , NiCl 2 , CuCl 2 and ZnCl 2 ) are shown in Fig (1: a, b, c, d, e). Figure (1: a) shows FTIR spectrum of PVA/PPY. The bands appear in the region 3300 -3500cm -1 due to N -H stretching frequency of an aromatic amine, Q Adeloju et al [6]. A broad band observed at 3418cm -1 in the spectrum of PVA/PPy powder and NH region also shows dependence of the doping anion of organic acids. Anion which typically forms hydrogen bond with amine group shows variations in the intensity and shape of the NH band, thus indicating that the doping is higher in the sample. The bands at 2919 cm -1 and 2955 cm -1 are due to CH 3 and CH 2 (C -H stretching).
The two bands observed in the range 1400-1467Cm

4.2.X-Ray Diffraction
Figure (2: a) presents X-ray diffraction pattern for uncapped PVA/PPY which exhibit strong diffraction peak for PVA at about 2θ = 20 º correspond to the PVA crystalline phase, T Trindade et al [11],and exhibit a peak at about 2θ = 24.6 º a characteristic peak of amorphous polypyrrole, Kyung Jin Lee et al [12] .  , 29 º for FeCl 3 , NiCl 2 , CuCl 2 and ZnCl 2 respectively. The X-ray diffraction pattern of nanocomposites show that the intensity of diffraction peaks was decreased and broad. This attributed to the capped between PVA/PPy nanocomposites with metal decreased the crystallinity of metal chlorides. Also, it is confirmed that the metal chlorides retained those structures even though it's dispersed in PVA/PPy during polymerization reaction, Chivukula Srikanth et al [13].

Transmission Electron Microscope (TEM)
The size and shape of synthesized PVA/PPy nanocomposite with FeCl 3 , NiCl 2 , CuCl 2 and ZnCl 2 were determined by TEM. Figure (3: a, b, c, d, e) presents the TEM images of nanocomposite materials. All of these composites present uniform sizes and morphologies. Figure (3: a) shows the PVA/PPy with an average diameter 58nm when the metals added to the PVA/PPy as in figure (3: b, c,  .24) nm respectively the particle size of nanocomposite becomes smaller this attributed to the effect of large particles size of polymer on the particle size of metals, due the decrease in ionic radius of metals which produce an agglomeration in TEM image.    Figure (4:a, b, c, d, e) shows the variation of the conductivity with inverted temperature for PVA/ PPY uncapped and PVA/PPY with metal chlorides (FeCl 3 , NiCl 2 , CuCl 2 and ZnCl 2 ) nanocomposite respectively. The electrical conductivity increases with increasing temperature indicating that, the increase can be assigned to two factors: the increase in the mobility of charge carriers and the increase in the rate of charge carrier's generation, R Sing et al [14]. Also from the figures it can be noticed that, the electrical conductivity of PVA/PPY is less than PVA/PPY with metal chlorides nanocomposite. The increase in electrical conductivity  with added metals can be attributed to the creation of induced charge carriers in PVA/PPY matrix. This is because of the metal ions coordinated through ionic bonds with hydroxyl group belonging to the different chains in PVA and with the hydrogen in the N-H group of the pyrrole ring, Anurag Krishna et al [15].The addition of metal increase the volume required for ionic carriers to drift in the polymer matrix. This enhances the ionic mobility and hence increases the conductivity. The dependence of electrical conductivity  of PVA/PPY and PVA/PPY metal nanocomposite at (393K) is shows in table (1) The table given that the PVA/PPY with metal nanocomposite is higher conductivity than PVA/PPY. Also it can be observed the high conductivity for Cucl 2 doped with PVA/PPY, this could be attributed to small polaron hopping. So the prepared PVA/PPY/ CuCl 2 nano composites in the present study are expected to be more useful in photonic and electronic device applications, Alabur Manjunath et al. [16] .The results obtained in the present work is of the same order as it is reported in the literature, Ahmed hasim et al [17].

Conclusion
PVA/PPY nanocomposite with metal chlorides (FeCl 3 , NiCl 2 , CuCl 2 and ZnCl 2 ) have been synthesized by chemical oxidative polymerization method. FTIR analysis indicated strong interactions between metals and PVA/PPY matrix, leading to shifting of bands to higher wavenumbers. X-ray diffraction pattern of nanocomposites show the intensity of diffraction peaks was decreased and broad. This attributed to the capped between PVA/PPY nano composites with metal decreased the crystallinity of metal chlorides. TEM images showed that the particle size of nanocomposite becomes smaller, this attributed to the metal nanoparticles are entrapped in the PVA/PPY matrix. The DC electrical conductivity of PVA/PPY/metal chlorides gradually increased with added metals, this is attributed to the creation of induced charge carriers in PVA/PPY matrix. The high conductivity for CuCl 2 doped with PVA/PPY, could be attributed to small polaron hopping. So the prepared PVA/PPY/ CuCl 2 nano composites in the present study are expected to be more useful in photonic and electronic device applications