Ruthenium-catalyzed synthesis of butynediol ether trisiloxane surfactant

Butylenediol ether trisiloxane (BEOTSS) has been synthesized from butynediol ethoxylate (BEO) and 1,1,1,3,5,5,5-heptamethyltrisiloxane (MD^HM) by a hydrosilylation reaction using a ruthenium catalyst. The structure of BEOTSS was characterized by infrared spectroscopy (FT-IR) and nuclear magnetic resonance (¹H-NMR) spectroscopy. The effects of varying the reaction temperature, reaction time, raw material ratio and catalyst dosage on the conversion of MD^HM were investigated, and the catalytic reaction conditions were optimized by orthogonal tests. The optimum conditions were as follows: a catalyst dosage of 30 mg/kg, an n(BEO):n(MD^HM) ratio of 1.05:1, a reaction time of 6.0 h, and a reaction temperature of 100 ℃. Under these conditions, the conversion rate of MD^HM could reach 99%. The interfacial properties of BEOTSS were measured. The results show that the surface tension of a 0.1% BEOTSS aqueous solution is 22.5 mN/m at 25 ℃, and the critical micelle concentration (CMC) is 4.9×10^-5 mol/L, indicating that BEOTSS can significantly reduce the surface tension of water at low concentration and has excellent surface activity.