| Water-destructible polystyrene/polyacrylate sodium(PS/PAANa) blends have been prepared by in-situ bulk or emulsion polymerization. A kind of polystyrene(PS) foam was made from such blends by "two-step" process. The foam was also water-destructible under proper condition,and the water-destructing speed was adjustable.Polyacrylate sodium(PAANa) particles were prepared by inverse emulsion polymerization. The factors that affected the stability of the inverse emulsion polymerization ,such as the emulsifier system, water/AANa ratio and pH of AANa solution ,were studied. The factors that affected the absorbing ability of PAANa,such as the amount of crosslinker , initiator and pH of AANa solution, were also studied. As a result, the optimized reaction condition of PAANa was obtained.The PS/PAANa blends did not show water-destructible performance without emulsifier. The water-destructing speed of the blends increased at first and then decreased with the increase of the amount of emulsifier added at the blends. When such emulsifiers existed, the increase of absorbing ability or the amount of AANa would accelarate the water-destructing speed of the blends. The water-destructing speed of the blends would decrease if PS was crosslinked or copolymered with methyl methacrylate(MMA) or the increase of molecular weight of PS.The water-destructed production of the blends was PS particles covered with PAANa hydrogel, and the average diameter of such praticles was smaller than one millimeter.The water-destructing mechanism of PS/PAANa blends was that water passed through emulsifier in PS, and entered PAANa,then PAANa absorbed water and expanded ,finally the expanding force caused the water-destruction of the blends.A foam that expanded 20 times was made from PS/PAANa blends by "two-step" process.The foam was also water-destructible under proper condition. Moreover,the water-destruction process was complete and the water-destructed speed was adjustable.
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