Characterization of reacting polymer systems by temperature-modulated differential scanning calorimetry

The benefits of temperature-modulated differential scanning calorimetry to characterize reacting polymers are illustrated for different experimental systems. The effects of combined isothermal and non-isothermal cure paths on (de)vitrification, mobility-restricted reactions, and relaxation during vitrification are discussed for anhydride- and amine-cured epoxies. The simultaneous measurement of heat capacity, heat flow, and heat flow phase provides an excellent tool for mechanistic interpretations. The influence of the metakaolinite particle size on the production of inorganic silicate-metakaolinite polymer glasses is treated as an example. These principles are further illustrated for primary and secondary amine-epoxy step growth reactions, and for styrene-cured unsaturated polyester chain growth reactions with 'gel effect'. Finally, the effects of isothermal cure and temperature on reaction-induced phase separation in a polyethersulfone modified epoxy-amine system are highlighted.