Thermally stable maleimide polymers for second-order nonlinear optics

Summary form only given. N-Phenyl maleimide with an isocyanato group was synthesized and employed in the coupling reaction with 4-(nitrophenyl)-L-prolinol (NPP). The radical homopolymerization and copolymerization with methyl methacrylate (NIMA) of the resulting maleimide were carried out to produce poly(N-phenyl maleimide) and poly[(N-phenyl maleimide-co-methyl methacrylate)] containing NPP units through urethane linkages. The glass transition temperature of the copolymer (60% NB4A composition) was found to be 161/spl deg/C in the DSC thermogram. No distinctive glass transition was observed for the homopolymer. The spincoated films onto indium tin oxide glass were poled using the corona poling technique. The electro-optic (EO) coefficient was measured using the simple reflection method. The polymers had fairly large EO coefficients ranging 10-11 pm/V at 632.8 nm wavelength. The homopolymer showed excellent thermal stability. No significant relaxation was observed for 200 min at 80/spl deg/C.