Photochromic Azo Polysemicarbazides with Biocompatibility Behavior

Two kinds of azo polysemicarbazides were prepared based on 3,3＇-azobis（benzoylhydrazide）（ABH） and two kinds of diisocyanates via solution polymerization.The structures were characterized by Fourier-transform infrared（FT-IR） technique and elemental analysis.Inherent viscosities of the polymers were 0.32 and 0.29 dL/g and both could be dissolved in H2SO4 and polar organic solvents.Thermal gravimetric analysis（TGA） presented a multi-step degradation and a decomposition temperature range of 230-280 ℃.And photoisomerization of the azo polymers in solvent of N,N-dimethyl acetamide（DMAc） was confirmed by Ultraviolet-visible spectroscopy（UV-Vis）,suggested the isomerization appearing under the ultraviolet irradiation at 365 nm and recovering completely by visible light irradiation or kept in the dark.Transmission electron microscopy（TEM） of polysemicarbazides before and after soaking in bovine serum albumin（BSA） solution confirmed the biocompatibility of azo polymers.