Effect of polysaccharide polymers on the surface and foam properties of aqueous film-forming foam

Three kinds of polysaccharide polymers were used as the proposed foam stabilizers in aqueous film-forming foam (AFFF). The effect of polysaccharide polymers on viscosity, surface tension, foaming ability and foam stability of AFFF was discussed by various analytical methods. The results shows that the addition of polysaccharide polymers slightly increases the surface tension of foam solution, while the combination of xanthan gum and gelatin presents the least negative influence on the surface tension of foam solution. Especially, the addition of gelatin improves the foaming ability of AFFF while both xanthan gum and sodium alginate decrease the foaming ability of AFFF. The combination of xanthan gum and gelatin can effectively balance the foaming ability and foam stability of AFFF, which is ascribed to the increases of viscosity that enhances the surface strength of foam liquid film and decreases the diffusion of water in the liquid film, thus effectively slowing down the drainage rate and bubbles coarsening of foam.