Azobenzene-modified pullulan with different substitution degrees were prepared by changing feed molar ratio of 4-phenylazophenyloxybutyrate acid to pullulan. The structure of the modified pullulan were characterized b...Azobenzene-modified pullulan with different substitution degrees were prepared by changing feed molar ratio of 4-phenylazophenyloxybutyrate acid to pullulan. The structure of the modified pullulan were characterized by 1 H NMR and FTIR spectroscopies. The substitution degrees were determined by elemental analysis and UV-Vis spectra. Photochromism property in solution was investigated by UV-Vis spectroscopy, isomerization behavior of azobenzene moeties of polymer under irradiation at 350 nm is obvious. After 4 min irradiation, trans isomer of sample 3 change into cis isomer completely. Furthermore, unlike pullulan, which is soluble only in H2O or DMSO, the solubility of these products in common organic solvent increased greatly.展开更多
文摘Azobenzene-modified pullulan with different substitution degrees were prepared by changing feed molar ratio of 4-phenylazophenyloxybutyrate acid to pullulan. The structure of the modified pullulan were characterized by 1 H NMR and FTIR spectroscopies. The substitution degrees were determined by elemental analysis and UV-Vis spectra. Photochromism property in solution was investigated by UV-Vis spectroscopy, isomerization behavior of azobenzene moeties of polymer under irradiation at 350 nm is obvious. After 4 min irradiation, trans isomer of sample 3 change into cis isomer completely. Furthermore, unlike pullulan, which is soluble only in H2O or DMSO, the solubility of these products in common organic solvent increased greatly.
