MEASUREMENT OF THERMOPHYSICAL PROPERTIES OF POLYVINYL-ALCOHOL COMPLEXED WITH SOME METAL-IONS

Polyvinyl alcohol (PVA)-Cu(II) and PVA-Cr(III) complexes were prepared with different concentrations of CuCl2 and Cr(NO3)3 salts. The structures of the obtained complexes were investigated using UV spectroscopy and x-ray analysis. The thermal properties (volumetric heat capacity, thermal diffusivity, and thermal conductivity) of aqueous solutions of PVA-metal complexes have been measured using the hot-wire (and strip) technique as a function of temperature (20-degrees-80-degrees-C). The results show that the values of the thermal properties depend on the type and the concentration of metal ions bound to the polymeric chains of PVA and the temperatures. However, a considerable increase in the values of the thermal properties was observed for PVA-Cu(II) complex. The type of metal salt under investigation affects the structure of PVA. The complex of PVA-Cr(III) is more thermally stable than the complex of PVA with Cu(II). However, both polymer-metal complexes showed good properties which may make them acceptable for some practical uses.