Vibrational spectroscopic studies of isotactic styrene copolymers containing mass defects in the form of styrene-d8 units are presented. The results indicate that the changes which occur in the vibrational spectrum of isotactic polystyrene upon the introduction of styrene-d8 defects can be interpreted solely in terms of the delocalization of chain vibrations and the appearance of localized defect modes. Frequency shifts and band broadening observed at low defect concentrations are shown to be consistent with an activation of the density of states of the protonated polymer.
Paul C. Painter, Stephen E. Howe, and Michael M. Coleman, "The Vibrational Spectrum of Isotactic Polystyrene II: The Effect of Mass Defects," Appl. Spectrosc. 38, 190-195 (1984)