Thermal polymerization has not been extensively studied as a technique for the polymerization of bicontinuous microemulsions. Other more rapid techniques have been employed such as visible- and UV-initiated polymerization, However, the industrial preparation of porous solids would be facilitated by the use of the cheaper and simpler thermal polymerization. The effects of changing composition of the precursor on the resulting matrix morphology for thermally polymerized microemulsions were studied. The factors examined were the surfactant loading of the aqueous phase, the aqueous to organic phase ratio, the monomer ratio of the organic phase, and the cross-linear content of the organic phase. SEM, drying rate studies, and freezing point depression measurements were used to determine matrix morphology. The surfactant loading of the aqueous phase and the cross-linker content of the organic phase were found to have no significant effect on the morphology while the phase ratio and monomer ratio were found to have significant effects on the resulting polymer matrix morphology.