Heterogeneity of amorphous polymers as studied by quasielastic neutron scattering in positron annihilation lifetime spectroscopy

It is believed that a key to understand anomalous dynamics of glass-forming materials is dynamic heterogeneity. In this report we evaluate the spatial size of the heterogeneity of glass-forming polybutadiene on the basis of t he quasielastic neutron scattering and positron annihilation lifetime spect roscopy data and compare it with the reported data. We propose an empirical relation of the spatial scale between the cooperatively arranging region C RR in the supercooled state and the Boson peak in the glassy state.