Study on the Development and Performance of a New Concrete Antifoaming Agent

Gemini surfactant acetylene glycol polyethers and polyhydrosilicone oil were used as raw materials to generate the acetylene glycol surfactants with defoaming, antifoaming properties, and polyether modification through a hydrolyzation reaction. A novel silicone surfactant based on acetylene glycol-modified polyoxysilane, which has the advantages of low surface tension and good water solubility. Its structure characterized by infrared. Finally, the new silicone surfactant prepared was emulsified with a composite emulsifier, and a new concrete defoamer was prepared by a mechanical method. The defoaming performance, foam suppression performance and surface tension were tested. The results showed that the new silicone surfactants contained functional groups of acetylene glycol and siloxane. The composite emulsifiers were Span40 and Tween60, which the HLB value was 10, the amount was 5% and the emulsification time was 30 minutes. The prepared new concrete defoamer has good defoaming and antifoaming properties with a low surface tension.

Optimization and Performance Evaluation of an Environmentally Friendly Fluorine-Free Foam Extinguishing Agent

Fluorine-free foam fire extinguishing agents are environmentally friendly compared with aqueous film-forming foam fire extinguishing agents (AFFF). Design-Expert 11.0 software and the Box-Behnken design principle were used to optimize the foaming agent formulation which is the core of fluorine-free foam extinguishing agents and regression models of the expansion ratio (α), 50% drainage time (t50%) and surface tension (γ) were established. Furthermore, the optimal combination of foaming agent various factors (the mass fraction of APG0810, silicone surfactant, SDS and BS-12) were predicted by the regression models. The prediction results showed that when the mass fraction of APG0810, silicone surfactant, SDS and BS-12 were 2.0%, 0.242%, 0.116% and 0.349%, respectively, the comprehensive foaming agent performance was highest. The α, t50% and γ of the optimized foaming agent were 8.0, 376 s, and 24.1 mN/m, respectively. The fluorinefree foam fire extinguishing agent was prepared by compounding the optimized foaming agent with foam stabilizers and other additives, resulting in a surface tension of 24.3 mN/m and a spreading factor greater than zero. The, α, t50% and sealing time of the fluorine-free foam fire extinguishing agent were 7.6, 541 s, and 895 s, respectively, which were 8.6%, 16.1%, and 14% higher than commercial 6% AFFF.