Irradiation effect of photostability of poly(vinyl chloride) in presence of inorganic complexes

          Five metal ion complexes of Ni(II), Cu(II), Zn(II), Cd(II) and Sn(II) with potassium 2-(4-isobutylphenyl) propanoate, as a ligand (L) has been prepared in alcoholic medium.
These complexes are:
Bis2-(4-isobutylphenyl) propanoato  Nickel(II), NiL2
Bis2-(4-isobutylphenyl) propanoato  Cupper(II), CuL2
Bis2-(4-isobutylphenyl) propanoato  Zinc(II), ZnL2
Bis2-(4-isobutylphenyl) propanoato  Cadmium(II), CdL2
Bis2-(4-isobutylphenyl) propanoato  Tin(II), SnL2
          The ligand (L) and its metal ion complexes were characterized quantitatively and qualitatively by using: FTIR, UV-visible spectroscopy, magnetic susceptibility, conductivity measurements and melting point. According to the spectral data of the complexes an octahedral geometry was suggested for these complexes except Cu(II) complex which exhibit a square planer structure. In this work the prepared complexes of 2-(4-isobutylphenyl) propanoate were used to enhance the photostabilization of polyvinyl chloride (PVC).PVC has been mixed with these complexes in Tetrahydrofuran solvent which containing 0.5 % concentration of complex by weight, which produced by the casting method from Tetrahydrofuran solvent. The photostabilization of polyvinyl chloride films were studied at room temperature under irradiation of light( λ= 320)nm wave length with intensity of  7.75*10-7Ein Dm-3.S-1 The photostabilization activity of these compounds was determined by monitoring the hydroxyl (IOH) , polyene I(c=c)and carbonyl (ICO) indexes, weight loss method with irradiation time. It was found that carbonyl, polyene and hydroxyl indexes values increased with irradiation time and this increase depend on the type of additives. The surface morphology for these films was studied during irradiation time.  The changes in viscosity average molecular weight of PVC with irradiation time were also tracked (using Tetrahydrofuran as a solvent).The quantum yield of the chain scission (Φ) of these complexes in PVC  films was also evaluated.cs  The following trend was obtained for the photostabilization effect on PVC films in presence of additives as shown below: PVC<ZnL2<CdL2<CuL2<SnL Increasing the photostability  According to the experimental results obtained several mechanisms were suggested depending on the structure of the additives. Among these mechanisms,HCl scavenging, UV absorption, peroxide decomposer and radical scavenger for photostabilizer additives.