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Radical thermally initiated homopolymerization of methacrylic monomers based on aurone has been studied. Photochemical properties of these methacrylic monomers by UV-visible spectroscopy were investigated. It is shown that the new compounds are capable to radical homopolymerization and photoinduced cis-trans isomerization. It was found that increasing the electron donation of the substituent accelerates the process of radical homopolymerization of monomers. It was found that increasing the electron acceptance of the substituent accelerates the process of cis-trans isomerization. The rate constants and half-transformation times of cis-trans photoisomerization were determined by the tangent of the slope of the dependence Ln(Dfss-D0)/(Dfss-Dt) on the irradiation time of the solutions. [ABSTRACT FROM AUTHOR]

In this work we report preliminary results obtained for methacrylic polymers incorporating aurone side-group as photochemical active molecule. The aurone polymers were obtained by a three-step synthetic approach: (2Z)-6-hydroxy-2-(4-R-benzyliden)-1-benzofuran-3(2H)-ones were synthesized by using condensation reation of 6-hydroxybenzofuran-3-one with benzaldehydes; then methacrylate monomers were synthesized by reaction the alcohols with methacryloyl chloride; and the polymers were synthesized by free radical polymerization. Polymers were characterized by 1HNMR spectroscopy and DSC techniques. Their physicochemical properties are determined by absorption, fluorescence excitation and emission spectroscopies. [ABSTRACT FROM AUTHOR]

Polyethylene imines having 4-methoxyazobenezene group through methylene spacer groups (PEI6 M) were synthesized and their photochemical, thermooptical as well as photoorientational behavior were investigated. PEI6 M films showed high dichroism and order parameter values after annealing and developed out-of-plane order. Multiply-layered films exhibited reflection band and reflection band was almost disappeared by annealing the films at 80°C. In addition reflection band was again observed by UV light irradiation because of reorientation of azobenzene groups from out-of-plane order to random state. The photochemical control of molecular orientation of PEI6 M between random state and out-of-plane structures were achieved by combination of thermal and photochemical processes. [ABSTRACT FROM AUTHOR]