Preparation Of Porous Polymer And Its Composite Materials Using HIPE As Templates

Highly porous polymer materials has been widely used in the biomedical, the removal of organic chemicals, catalytic chemistry, the separation of solid impurities in water, liquid chromatography, and electro-chemical sensor fields because of their fascinating characteristic such as high specific surface area and low density.Various methods have been used for the preparation of the porous polymer materials. However, the common gas blowing techniques can not be precisely controlled the size and distribution of the pores. In rrecent years, the technology of high internal phase emulsion as templates has attracted much attention in the study of the materials preparation technology. High internal phase emulsions(HIPEs) are two-phase liquid-liquid systems in which one of the phases, the internal or the droplet phase, make up more than 74% of the emulsion volume. Solidification of the continuous phase can produce porous materials since polymerization occurs around and between the emulsion droplets. Therefore, as long as the suitable templates of high internal phase emulsions were prepared, the pore size and distribution can be precisely be controlled.In this article, we prepared classic poly(styrene/divinylbenzene) porous materials using the high internal phase emulsion as templates. Based on this poly(styrene/divinylbenzene) porous materials, we also prepared Poly(styrene/ vinyl acetate) porous materials and Poly(styrene/acrylonitrile) composite. The brief contents and results are as follows:1. In this article, the classic poly(styrene/divinylbenzene) porous materials were prepared using the high internal phase emulsion as templates. The mechanism of preparing polystyrene porous materials was studied, and the effects of emulsifier, pore-forming agent, and the ratio of reactants on the preparation of this porous materials was also examined. The pore structures of the porous materials were characterized by SEM. The results indicated that the porous materials have open cells(voids) and interconnect windows between adjacent voids.2. Based on the preparation technology of polystyrene porous materials, we havesynthesized the poly(styrene/ vinyl acetate) porous materials by addition of an aqueous solution of CaCl₂ and K₂SO₄ to a mixture of monomers plus surfactant. The effects of content of the surfactant, prepolymer time, the reaction temperature, and the vinyl acetate content on the preparation of the porous materials were studied. The morphology of the materials were characterized by SEM.3. Poly(styrene/acrylonitrile) based composite were prepared by immersing the poly(styrene/drvinylbenzene) porous materials in the acrylonitrile/AIBN solution. The effect of dipping time, initiator, and reaction temperature on the preparation of the composite was studied. The morphology of the composite was characterized by SEM. The obtained Poly(styrene/acrylonitrile) based composite exhibited high strength and hardness.