Photochemical transformation in poly(acrylic acid)/poly(ethylene oxide) complexes

The poly(acrylic acid)/poly(ethylene oxide) (PAA/PEO) complexes with different stoichiometric ratio were obtained from aqueous solutions, The chemical structure of these blends in solid state and the interactions between components has been studied using mainly FT-IR spectroscopy. The miscibility of components was proved also by differential scanning calorimetry (DSC). The films of both pure polymers and their blends at different compositions were UV-irradiated (lambda = 254 nm) in air atmosphere. The course of photochemical transformations has been monitored by absorption spectroscopy (FT-IR, UV-vis). DSC X-ray diffraction and thermogravimetry, which was also applied for estimation of the thermal properties of samples studied. It was found that photooxidative degradation is less efficient in PAA/PEO complexes than that in PAA and PEO exposed separately. The most photostable was PAA/PEO (50/50) blend. PAA disturbs crystallization PEO in the blends but changes in crystallinity degree of PEO/PAA during UV-radiation were negligible. Thermal stability of PAA/PEO complexes is lower comparing to pure components but UV-irradiation does not cause significant changes in thermal resistance of blends studied. (c) 2005 Elsevier B.V. All rights reserved.