Abstract
Dynamic birefringence and dynamic viscoelasticity of bisphenol A polycarbonate were simultaneously measured over a wide range of temperature from -150 to 180°C. Large γ dispersion observed for the complex Young's modulus was found to be inactive for the complex strain-optical coefficients, which is the ratio of birefringence to the strain. The present result indicates that γ dispersion cannot be attributed to the reorientation of any atomic groups, but to the relaxation of internal strain by translational motions. Dynamic birefringence was anticipated to be a new experimental method for the subrelaxation of glassy polymers.
