High internal phase emulsions (HIPEs) containing divinylbenzene and 4-vinylbenzyl chloride and the morphology of the resulting polyHIPE materials

The type of porogen added to the continuous phase of HIPEs containing divinylbenzene strongly in¯uences the morphology of the resulting PolyHIPE foam. The cell size was reduced as the solvent became a better cosurfactant, as inferred from surface pressure measurements of ®lms representative of each HIPE continuous phase. In addition, this caused the windows connecting adjacent cells to increase, to such an extent in two cases that the cellular morphology was apparently lost. The surface area increased as the solubility parameter of the solvent approached that of the polymer, however the materials with highest surface areas also had a noncellular morphology and were very weak mechanically. This could be recti®ed by the use of mixtures of the solvents investigated, producing materials with surface areas up to 554 m2 g21, a cellular morphology and good mechanical properties.