Published online by Cambridge University Press: 15 February 2011
Differential scanning calorimetry (DSC) was used to study blends ofpolystyrene (PS) and poly (p-Methylstyrene) (PpmS). The presence of twoglass transitions on heating after quenching was interpreted as evidence ofphase separation at the temperature of the liquid before quenching. Thesmall difference between the glass transitions of the homopolymers in thePS/PpmS system of “13 K limits the reliable detection of double glasstransitions for blends to concentrations between 30 and 70%. The results ofthe DSC technique are supported by comparison with small angle neutronscattering (SANS) data.