Azo dye based poly(alkyloxymethacrylate)s and their spacer effect on optical data storage

Two series of new sudan dye based poly(alkyloxymethacrylate)s were synthesized with varying even number of methylene spacers. The structure of the polymers was confirmed by FT-IR, ¹H and ¹³C-NMR spectroscopy. Thermal stability, glass transition and melting temperatures of the polymers were investigated with thermogravimetric analysis and differential scanning calorimetry respectively. Thermal stability of the polymers decrease with the increasing chain length of the methylene chain. The substituent on the azo moiety in the pendant side chain polymers has less thermal stability than the unsubstituted counterpart. The optical characterization of the polymers was done by formation of the holographic grating using 514.5 nm line of the Ar ion laser as source. The diffraction efficiency of the grating on the polymeric film was studied by varying the length of the methylene spacer, concentration and writing beam power.