Zero-birefringence polymer by the anisotropic molecule dope method.

We propose using the anisotropic molecule dope method for synthesizing a zero-birefringence polymer that showed no orientational birefringence at any orientation degree of polymer chains. In this method a rodlike molecule with polarizability anisotropy was chosen to compensate orientational birefringence. The zero-birefringence polymer was synthesized by doping of 3-wt.% trans-stilbene as an anisotropic molecule into poly(methyl methacrylate). The zero-birefringence at the 590-nm wavelength in the drawn film and the injection-molded plate made from the zero-birefringence polymer was confirmed by the rotating parallel nicols method. Furthermore, high transparency (37.2 dB/km) of the zero-birefringence polymer at the 633-nm wavelength was confirmed by the light-scattering measurement.