Synthesis and properties of rosin-based polyoxyethylene amine gemini surfactants

Four rosin-based polyoxyethylene amine gemini surfactants N, N'-methoxypolyethylene glycols-N, N'-dehydroabietylamine-α, ω-promethylene diamine (RPG550, RPG1000, RPG2000, and RPG5000) with different molecular weights, were synthesized from dehydroabietylamine through N-alkylation reactions. The structures of these compounds were confirmed by FT-IR and 1H NMR, and their surface activities were investigated and analyzed. The results showed the CMC and γcmc values of these four compounds were lower than that of commercial TX-10. The CMC values of RPG550, RPG1000, RPG2000, RPG5000 and TX-10 were 1.00×10-3, 9.75×10-4, 5.25×10-4, 1.90×10-4, and 2.03×10-3 mol/L, respectively. The γcmc values of these surfactants were 26.4, 27.5, 22.8, 22.2, and 31.6 mN/m, respectively. These compounds have excellent emulsifiability in the turpentine/water system and the liquid paraffin/water system. They also have good foam inhibition and defoaming power properties, and the foam inhibition property of RPG is significantly better than that of TX-10.