Polymer-polymer miscibility investigated by temperature modulated differential scanning calorimetry

In this paper we will review the main features of using both temperature modulated differential scanning calorimetry, T-m.d.s.c., and conventional d.s.c. for investigating phase behavior of polymer mixtures by reference to blends of acrylonitrile-butadiene-styrene copolymers with poly(methacrylate) and chlorinated polymers with aliphatic co-polyesteramides, respectively. We will also elaborate on more recent results concerning the application of T-m.d.s.c. to investigate enthalpy recovery in a blend of polystyrene and a random copolymer of styrene and para-fluorostyrene and whose glass transition temperatures are separated by only 3°C. It will be shown that, although the resolution of T-m.d.s.c. compared to conventional d.s.c is strongly enhanced, unambiguous conclusions about miscibility still requires enthalpy relaxation studies. The advantage of T-m.d.s.c becomes especially clear when overlapping signals such as glass transition and exothermic processes are present.