Synthesis and performance study of cationic surfactants containing different quantities of hydroxyl.

Three hydroxyl-containing cationic surfactants are synthesized and characterized by FTIR and (1)HNMR, and their thermal stability is tested and analyzed. The surface activity, adsorption and aggregation behavior of the synthesized target product were investigated by testing its contact angle, static surface tension and dynamic surface tension. As the number of hydroxyl groups increases, the maximum adsorption amount (Γ (max)) of molecules at the interface gradually decreases, and the minimum area occupied by each molecule (A (min)) increases, suggesting that the introduction of hydroxyl groups weakens the interfacial accumulation ability between molecules and increases the hydrophilicity. In addition, cationic surfactants with different hydroxyl groups show clear differences in the performance test. The DMAE exhibits excellent foaming ability and salt tolerance, while TMA offers the best alkali resistance. In comparison, MDAE provides greater advantages in terms of dynamic surface tension and wetting time, while also demonstrating strong anti-static properties. In short, the TMA is suitable for scenarios with high requirements for alkali resistance and static adsorption performance. The comprehensive performance of the DMAE is the best, suitable for scenarios with high requirements of salt resistance, foam performance and anti-static performance. The MDAE possesses outstanding dynamic performance, making it suitable for applications requiring rapid wetting and dynamic surface adaptation.