| The polymer conformation will be changed and the adjacent non- chromophores will take place cooperative motion along with the structural transition of the chromophores because of the cis-trans isomerization of azo-benzene chromophores under special wavelength illumination and the long-distance elastic force function among the side chains, when there are long flexible groups in the side chains and exists strong polar push-pull configuration in both of the non- chromophores and chromophores. Azo-polymers can combine this photo-responsive behavior with its flexible and easy processing properties, which endows azo-polymers great potential application value in optic information storage and optical switching fields. This study has been the polymer researching frontiers and opens out a good foreground.In this study, two kinds of side-chain azo-polymers had been obtained using two different kinds of azobenzene monomers and polymer main chains through graft polymerization. The method is rather simple and the intermediates and the final products can be easily purified. Structure of intermediates and final products were characterized by Fourier Transform Infrared Spectrum, Ultraviolet Visible Spectrum, Elemental Analysis, etc. Their thermal stability was studied by Differential Scanning Calorimetry method. In addition, the structure was determined further by it. The photoresponsive properties range from 200nm to 800nm of the products had been investigated by the Ultraviolet Spectrophotometer. In addition, the PH sensitivity and the ultraviolet irradiation effect on the conductivity of the products had been explored. Poly (glycidyl methacrylate)/lead zirconate-titanate composites had been prepared by mechanical blending, pressing into disc, and high voltage polarization. Their dielectric and piezoelectric properties were investigated by HP4294A precision impedance analyzer and ZJ-3A type quasi-static d33 measuring instrument respectively.Experiment results show that azo-polyimide has short side chain and its decomposition temperature reaches 344.3℃; the azo-polyimide can dissolve in water completely to form uniform and transparent real solution, it shows the strongest absorption peak under neutral condition, the absorption peak decreases and generates red-shift when the solution is under acidic or basic condition. Furthermore, study indicates that conductivity of the solution increases along with the 365nm ultraviolet illumination, which goes back to the former value again when it has been put in dark for 24h.PGMA-NBS also has excellent thermal stability, which starts to decompose at 317℃, and partial crystallizes after heat treating. The PGMA-NBS can dissolve in acetone completely. In addition, the solution displays strong absorption at 380nm and 320nm and this absorption varies with illumination time of 365nm ultravioler light. The dielectric constant of PZTPGMA-NBS/PZT composites increases along with increase of testing frequency. Changes of the dielectric constant and the dielectric losses according to volume fraction of PGMA-NBS are in the same line. Both of them increases initially and then decreases and exhibits the strongest value at 30% volume fraction. However, piezoelectric constant decreases by the addition of PGMA-NBS, and descent rate before 20% is lower than that after it. |
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