Tuning stability and thermal rheology properties of the fluorine-free foams co-stabilized by guar gum and surfactants

The development of highly stable and environmentally friendly foams is of utmost urgency. This study systematically investigated the effects of temperature on the viscosity and viscoelasticity of fluorine-free foams stabilized by guar gum (GG), silicon, and hydrocarbon surfactants. The experiment investigated the surface properties and foaming ability of various hydrocarbon surfactants, and selected the excellent BS-12 and the silicone surfactant LS-408L for compound use. The research found that the viscosity of the LS-408L/BS-12 solution increased as the concentration of GG increased. Among them, when the concentration of GG was 0.2wt%, the foam exhibited excellent stability. The rheological tests demonstrated that both the LS-408L/BS-12/GG stabilized foam solution and the foam exhibited the non-Newtonian fluid characteristics of shear thinning. As the temperature rises, the viscosity and viscoelasticity of the solution and the foam continue to decrease. It is notable that when the temperature reaches 67 °C, the loss factor (tan δ) is much greater than 1, indicating that the foam exhibits a significant dominant viscous behavior. Moreover, when the temperature reached 80 °C, the foam drainage accelerated, and the drained liquid exhibited a dynamic elastic response structure under the effect of high temperature. This study provides key data support for the optimized design of fluorine-free foam materials and has guiding significance for their application in different temperature environments.