Photoinduced birefringence properties of poly-schiff bases containing triphenylamine

Anisotropy was induced in poly-Schiff bases containing triphenylamine with linearly polarized light at 488 nm. Both writing and relaxation processes were described with a biexponential function. The alignment process involved two response modes: a fast response mode and a slow one. The fast response mode was associated with angular-dependent trans-cis photoisomerization, whereas the slow one was attributed to the position adjustment of the rigid main chains used to obtain well-aligned monodomains. The writing rate increased with an increase in the light intensity at a low intensity of the irradiation light. Structural factors such as main-chain rigidity seemed to play important roles in the remaining stored information. The two polymers had large photoinduced birefringence values (0.01 and 0.0015, respectively).