It is shown that for porous systems filled with a solvent, if the temperature domains of crystallization and melting of the
solvent are well separated, DSC technique, combined with suitably chosen thermal cycles, provides crystallization and melting
curves which are independent of a) the mass of the material, b) the thermal contact between DSC pan and material and c) the
thermal conductivity of the material. This method called DSC fractionation is applied to butyl rubber containing small water
nodules. Thermoporosimetry is then applied to get the size distribution of mesoscopic solvent droplets.