THE SYNTHESIS, CHARACTERIZATION, AND PHOTOCHEMICAL CROSSLINKING OF AN NLO EPOXY POLYMER

A photocrosslinkable second order nonlinear optical (NLO) epoxy polymer, Bisphenol A-Nitroaminotolane, containing covalently attached cinnamate side chain substituents (BisA-NAT-CM), was synthesized. After corona poling Second Harmonic Generation (SHG) is used to measure the relaxation of the anisotropy after the electric field is removed. Upon photolysis at 260 nm the cinnamoyl side chains undergo photochemical dimerization to crosslink the NLO polymer. Photobleaching is not a problem under these conditions. The photocrosslinked NLO polymer shows virtually no relaxation over a period of 500 hours at room temperature and good temporal stability at temperatures as high as 110°C.