Plastic and Polymer Technology (PAPT) Volume 2 Issue 1, March 2013 www.seipub.org/papt 1 Physical Physical Physical Physical Characterization Characterization Characterization Characterization of of of of Poly Poly Poly Poly (vinyl (vinyl (vinyl (vinyl pyrrolidone) pyrrolidone) pyrrolidone) pyrrolidone) and and and and Gelatin Gelatin Gelatin Gelatin Blend Blend Blend Blend Films Films Films Films Doped Doped Doped Doped with with with with Magnesium Magnesium Magnesium Magnesium Chloride Chloride Chloride Chloride E. M. Abdelrazek a , H.M. Ragab b , M. Abdelaziz a,c* a Physics Department, Faculty of Science, Mansoura University, Mansoura, Egypt b Physics Department, Faculty of Science, Al-Azhar University (Girls), Egypt c Natural Science Department, Community College of Riyadh, King Saud University, kingdom of Saudi Arabia a emabdelrazek@yahoo.com; a,c *mabdelaziz62@yahoo.com Abstract Abstract Abstract Abstract Polymeric films of pure poly (vinyl pyrrolidone) (PVP) and PVP/gelatin blend (60/40) containing various amounts of MgCl 2 were prepared using a casting technique. The structural and related physical properties of the prepared films were studied using different techniques. The obtained data revealed that the addition of gelatin and magnesium chloride causes structural variation in the PVP network. The X-Ray diffraction (XRD) patterns reveal that the amorphous nature of the blend increases with the concentration of magnesium chloride. Complex formation was confirmed by XRD and FT-IR analysis. The DSC results indicate that the addition of both gelatin and magnesium chloride to PVP changes the thermal behavior, such as the glass transition temperature and thermal stability. The analysis of the UV- visible optical absorption shows the decrease in the optical band gap (Eg) as dopant concentration increase. The reduced values of the optical gap improve their optical response, which can be used as optical sensors. The direct current (DC) electrical resistivity studies revealed a linear temperature dependence of the hopping distance (R o ) for all doped films. The conduction mechanism discussed based on the phonon- assisted charge carrier inter-polaron hopping model. Moreover, the addition of both gelatin and MgCl2 gives rise to improve the electrical properties of PVP film. The optical and electrical results suggested the applicability of these materials in optical and/or electrical sensors. Keywords Keywords Keywords Keywords Blends; XRD; FT-IR; DSC; Optical; Electrical Properties Introduction Introduction Introduction Introduction Polymer science has shown a tendency in the last decade to create blends of different polymers rather than to develop new polymers. Blending of polymers is one of the simplest means to obtain a variety of physical and chemical properties from the constituent polymers. The gain in newer properties depends on the degree of compatibility or miscibility of the polymers at a molecular level. Generally, the polymer– polymer miscibility is due to some specific interactions like dipole–dipole forces, hydrogen bonding and charge transfer complexes between the polymer segments. Water soluble polymers are important from industrial view point. Polyvinyl pyrrolidone (PVP) has excellent characteristics such as high-dielectric constant, dissolubility, stability, compatibility and resistance and large scale screen printing of PVP films at low cost is feasible. PVP is highly soluble in polar solvents such as alcohol, so it is preferable to avoid phase separation in the reaction. Another advantage of using PVP is that PVP can be thermally crosslinked and that makes the composites have outstanding thermal stability and high mechanical strength. Furthermore, the amorphous structure of PVP also provides a low scattering loss, which makes it an ideal polymer for composite materials for optical application. PVP thermally decompose before reaching its molten state. This terminates the application of this polymer. PVP is chosen as a matrix for the composites because of the two important characteristics. One is that PVP has good film-forming and adhesive behavior on many solid substrates and its films exhibit good optical quality and mechanical strength. Another is that the pyrrolidone group of PVP prefers to complex with many inorganic salts resulting in fine dispersion and surface passivation of them. Blending PVP with a potentially useful natural biopolymer such as gelatin seems to be an interesting way of preparing a polymeric composite. Gelatin not only maintains inherent biological activities of PVP, but also gains a lot of new properties and functions. Such a composite