Using polymer films to probe finite size effects in glass forming materials

In this paper we discuss a model used to describe data on the reduced glass transitions observed in thin free standing polymer films. The model is based on the simple ideas of an enhanced segmental mobility at the polymer free surface and the existence of a characteristic length for dynamics in glass forming materials. The model accurately describes the measured Tg values, and makes predictions on the length scale for dynamics at temperatures near and below the bulk Tg value.