A rigid polymer, for example polystyrene, exhibits a strong MW dependance on T g that is reflected in high values of T g,∞ and K; while a more flexible polymer, such as polydimethylsiloxane, exhibits smaller values of T g,∞ and K and hence the MW dependance on T g is far weaker. Previous work on PDLLA reported values of T g,∞ = 330 K and K = 7.30 × 10 4 K. Using these values we find that the Fox-Flory equation yields a predicted T g,theor. ≈ 326 K, for PDLLA which is in reasonable agreement with our calorimetric measurement of T g,DSC = 319 K, yet higher than T g,α = 298 K (Table ).