A microcalorimetric technique is described which enables an entire rubber cure curve to be recorded on a single sample quantitatively. It is non-destructive, operates at moderate temperatures and does not require separate extraction and analysis steps. The technique is used to record the cure reaction between a variety of isocyanate- and hydroxy-terminated polyfluoroethers. The effect on reaction rate of temperature, degree of cure and type of functional group participating in the crosslinking reaction are studied to provide a general description of the behaviour of mixtures of this type of material during processing.