Molecular weight dependence of the glass transition of cyclic polystyrene

The glass transition temperature (T(g)) of cyclic polystyrene was measured by differential scanning calorimetry. There was a marked difference in the glass transition behaviour between cyclic and linear polystyrene. In the low molecular weight region (M(n) 10(5)). Combining the results of specific volume, it is believed that the variation of T(g) with molecular weight does not depend only on free volume effects but that configurational entropy is also an important factor.