Preparation and Properties of Sulfonated Polystyrene Nanospheres-Polyacrylamide Hybrid Hydrogels

Polystyrene (PS) microspheres were prepared by emulsion polymerization. PS microspheres were sulfonated by concentrated sulfuric acid to obtain sulfonated polystyrene (SPS) microspheres. SPS-PAAm hybrid hydrogels were prepared by adding synthetic SPS microspheres as a multifunctional crosslinking point to the polyacrylamide (PAAm) chemical hydrogel network. The microstructure of SPS microspheres and hybrid hydrogel were observed by scanning electron microscopy and transmission electron microscopy. The effects of SPS microspheres on the gel fraction, swelling properties and mechanical properties of hybrid hydrogels were studied. Results show that with the increase of SPS dosage, the SPS-PAAm gel fraction increases first and then decreases, and the equilibrium swelling degree of SPS-PAAm hydrogel decreases. In addition, the addition of SPS microspheres can improve the mechanical properties of hydrogels. The tensile strength and the energy loss of hydrogel increase with the increase of SPS dosage, and there is physical interaction between SPS microspheres and PAAm molecular chains.