DOMAIN SIZE OF DYNAMIC HETEROGENEITIES IN ANTIPLASTICIZED POLYCARBONATE BY PROTON SPIN-DIFFUSION

Proton spin diffusion measurements were made using the Goldman-Shen te chnique of bisphenol-A polycarbonate containing 10 wt% trioctyl phosph ate at temperatures below the glass transition temperature. The proton lineshapes reveal the existence of dynamic heterogeneities in the gla ss and spin diffusion can be observed from the more mobile to the less mobile domain. The time-scale for spin diffusion is 4-10 ms and the m obile domain size is estimated at 11 Angstrom A at 339 K. This estimat e is consistent with a mobile domain of approximately two diluent mole cules and 11 polymer repeat units. This grouping can be compared with the results of a statistical lattice model used to estimate local envi ronments at this composition.