一种超支化偶氮聚氨酯的合成及其光致变色性能

以偶氮间苯二酚磺酸和4,4^/-二苯甲烷二异氰酸酯为原料,利用偶氮间苯二酚磺酸的羟基、磺酸基与4,4^/-二苯甲烷二异氰酸酯分子中的异氰酸酯基,通过A₂+B₃方法缩聚合成超支化偶氮聚氨酯,利用合成聚合物分子外围的羟基与丁二酸酐/偏苯三酸酐反应,改善超支化偶氮聚氨酯的溶解性.并通过IR、TG等对目标聚合物进行表征.采用UV-Vis光谱研究了合成偶氮聚合物的光致变色特性.结果表明:目标偶氮聚氨酯π→π^*跃迁最大吸收峰为425 nm,偏苯三酸酐改性超支化偶氮聚氨酯与超支化偶氮聚氨酯π→π^*跃迁最大吸收峰基本一致,丁二酸酐改性超支化偶氮聚氨酯偶氮基团π→π^*跃迁最大吸收峰由425 nm红移至501 nm.

Synthesis and Photochromic Performance of a Hyperbranched Azo Polyurethane

Using 4-((3,4-dihydroxyphenyl)diazenyl)benzenesulfonic acid and 4,4'-diphenyl- methane diisocyanate (MDI) as raw materials, the hyperbranched azo polyurethane was synthesized by A2+B3 polycondensation, with the reactions between phenolic hydroxy or sulfo group and isocyanate group. Then the peripheral hydroxyls of synthetic hyperbranched azo polyurethane reacted with succinic anhydride or trimellitic anhydride to to improve the polymer solubility. The target hyperbranched azo polyurethanes were characterized by IR, TG and UV-Vis spectrum. The UV-Vis spectra showed that both of the maximum absorption peaks of π→π^* in the unmodified hyperbranched azo polyurethane and the hyperbranched azo polyurethane modified by trimellitic anhydride were the same, at 425 nm, while the maximum absorption peak of π→π^* in hyperbranched azo polyurethane modified by succinic anhydride was red shifted to 501 nm.