Effects of internal-phase contents on porous polymers prepared by a high-internal-phase emulsion method

A series of porous polymers poly(styrene-divinylbenzene) was synthesized by the polymerization of 9 : 1 (v/v) styrene/divinylbenzene using high-internal-phase emulsions (HIPEs) as template, cetyltrimethyl ammonium bromide as a surfactant in the presence of water-miscible organic additives ethanol, with internal-phase contents varied from 82.5 to 94.0 %. The effects of the internal-phase contents on the microstructure of the resulting polymers were characterized by scanning electron microscopy and mercury intrusion porosimeter. The apparent density, compressive strength, water and toluene absorption and release behavior of the polymers with different porosity were investigated. The results showed that the properties of the porous polymer were significantly influenced by the internal-phase content. The increase in the internal-phase content increased the pore volume, thus increased the water and toluene absorption values, but decreased the apparent densities and the compressive strength of the porous polymers. The highest water and toluene absorption values were found for the sample prepared with the highest internal-phase content (94.0 %), which reached 11.65 and 21.64 cm(3)/g (based on the weight of the porous polymer), respectively. The water and toluene absorption kinetics of the porous polymers were well described by a pseudo-second-order kinetic model. The toluene release rates of the porous polymers were increased with the increased internal-phase content.