硬脂酸酯双子季铵盐的合成及性能研究OACSTPCD

A Gemini quaternary ammonium surfactant based on stearate(EG-18)was synthesized from stearic acid,N,N-dimethylethanolamine and 1,4-dibromobutane.EG-18 was characterized by IR and 1H NMR.The surface activity of EG-18 was studied by measuring the static surface tension and dynamic surface tension.The critical micelle concentration(cmc)of EG-18 was 1.32×10-3 mol/L,and the equilibrium surface tension at cmc(γcmc)was 35.68 mN/m.The results of dynamic surface tension vs.time showed that,when the concentration of EG-18 solution was as low as 1×10-5 mol/L,only induction region could be found in the curve,and the fast fall region and meso-equilibrium region would gradually appear with the increase of concentration.Equilibrium region was not founded at higher concentration(e.g.,1×10-2 mol/L)of EG-18 solution,due to the high steric hindrance of the Gemini surfactant,which hindered the rate of migration to the liquid surface.The results of dynamic contact angle showed that,the contact angle of EG-18 solution decreased with the increase of concentration,i.e.,the wetting effect of EG-18 solution on paraffin film increased.The differences between EG-18,D1821 and esterquat in wetting ability,turbidity,antistatic properties,softness and fabric whiteness were studied.The results showed that EG-18 had the highest solubility among the three.EG-18 had certain wetting ability to paraffin film,but its wetting ability was weaker than that of D1821 and esterquat.The antistatic performance of EG-18 was stronger than that of D1821.In terms of softness,the softening properties of the three substances were basically the same,and compared with the blank control group,the white cotton cloth was significantly softened.EG-18 had the least influence on the whiteness of white cotton cloth.