On segmental mobility in a compatible poly(α-methylstyrene)-block-polystyrene copolymer

Poly(α-methylstyrene)-block-polystyrene (PαMS-block-PS) containing various amounts of PoMS (from 13 to 81 wt %) were studied. The results of DSC showed a very broad, single Tg for all block copolymers studied. However, the spin-lattice relaxation rate in the rotating frame via cros polarization in NMR as a function of temperature indicate that the block copolymer has microheterogeneity at temperatures above the onset point of the glass transition but becomes homogeneous as the temperature approaches the midpoint of the glass transsition