两种偶氮分子玻璃材料的光致取向特性

利用光诱导双折射和偏振红外光谱法研究了2种无定形树枝状偶氮分子材料G1-AZ-CN和G2-AZ-CN的光致取向行为, 对其偶氮生色团及非光响应性星形核的光致取向速度、 取向松弛速度和饱和取向程度进行了系统研究. 结果表明, G2-AZ-CN中偶氮生色团和星形核的光致取向速度快于G1-AZ-CN, 但其取向松弛速度慢于G1-AZ-CN, 这与G2-AZ-CN具有更高的偶氮生色团密度有关. G1-AZ-CN具有较高的饱和取向程度及较好的取向稳定性. 与具有相同类型偶氮生色团的偶氮聚合物BP-AZ-CN相比, G1-AZ-CN和G2-AZ-CN中偶氮生色团表现出较慢的取向速度. 其取向行为与其特殊的星形分子结构有关.

Photoinduced Orientation of Two Dendritic Azo Amorphous Molecular Materials

The orientation behavior of two dendritic azo compounds, G1-AZ-CN and G2-AZ-CN were studied by photoinduced birefringence method and polarized infrared spectroscopy. The chemical structure difference between G1-AZ-CN and G2-AZ-CN is the density of azo chromophore. The orientation rate, relaxation rate and saturated orientation level of dendritic azo compound are related to its special chemical structures. Both azo chromophore and dendritic core of G2-AZ-CN show faster orientation rate but slower relaxation rate than that of G1-AZ-CN, which could be attributed to the higher azo chromophore density of G2-AZ-CN. G1-AZ-CN reserved higher photoinduced orientation after relaxation than G2-AZ-CN. The saturated orientation level of both azo chromophore and dendritic core of G1-AZ-CN is higher than that of G2-AZ-CN, in which the special chemical structure can play a critical role.