Preparation and the foaming activity of hydroxymethyl octadecyltrimethyl ammonium chloride

In this work, hydroxymethyl octadecyltrimethyl ammonium chloride (HM-OTAC) was obtained from the reaction between octadecyltrimethyl ammonium chloride (OTAC) and formaldehyde in different molar ratios. The effects of the reaction conditions (different molar ratios) on the properties of the product (surface tension, foaming, high temperature resistance, methanol resistance and salt resistance) were investigated. The results showed that the HM-OTAC produced under different molar ratios could lower the surface tension of water solutions more than the surfactant OTAC. The HM-OTAC (1:2) reduced the surface tension to 28.29 mN m(-1). The HM-OTAC produced under other molar ratios gave higher interfacial tensions than HM-OTAC (1:2). With increasing surfactant concentration, the foam volume first increased and then gradually decreased. At a concentration of 0.3 wt.%, the highest foam volume (460 mL) was produced with HM-OTAC (1:3). Compared to OTAC, the foams produced by each HM-OTAC surfactant exhibited higher temperature stability. In the presence of 30 mL methanol, the initial foam volume of all HM-OTAC surfactants (0.3 wt.%) was generally higher than that of OTAC. With 300 mL HM-OTAC (1:4) solution, the highest foam volume of 20.2 mL could be produced. HM-OTAC (1:3) showed the highest salt resistance.