Study On Synthesis And Property Of Gemini Surfactant Of The Type Of Quaternary Ammonium Salt

Synthesis of Gemini surfactant of the type of quaternary Ammonium Salt Appeared in the 20th century,90 years, They had higher surface activity and lower critical micelle concentration than the traditional surfactant, thus were widely used in many fields such as petroleum industry, new materials and biological technology, etc. In recent years, Scientific researchers focused mainly on researching Gemini surfactant of the type quaternary ammonium salt in the hydrophobic chain for symmetrical structure and also the spacer for longer hydrocarbon chains. For that reason, we launched a series of research work for synthesis of the Short of the spacer of Gemini surfactant of the type quaternary ammonium salt by the method of joining chain spacer, and new varieties were added. But there were difficulities in synthetizing the objective products compared to the former as a result of the existence of steric effect. Our research contents in this paper were got mainly as follows:(1) Symmetrical Gemini surfactant of the type of quaternary Ammonium Salts were synthesized by ethylene dibromide, N,N-dimethyldecylamine and N, N-demethyldo-decylamine which were raw materials, moreover, we could obtain the yeild of the objective products which were more than 98% and the contnet which were more than 95%. This synthesis method not only was very simple but also made us save the cost of raw materials compared to the method of joining hydrophobic chain in the former. At the same time, Asymmetric Gemini surfactant of the type of quaternary Ammonium Salts were also synthesized, moreover, we could obtain the yeild of the objective products which were more than 91% and the contnet which were more than 86%, so new varieties were added. Besides, Structurs of the objective products were identified by infrared spectrograph and we also detected existence of quaternary ammonium cations and bromoniumion, So we proved that the objective products were the types we needed.(2) we researched synthetic product of dissolubility, surface tension and critical micelle concentration, and research showed that synthetic products were well soluble in polar solvents and sparingly soluble in less polar solvents. In addition to this, their surface tension and critical micelle concentration were very low and we found that there were regularity in characteristic with the change of hydrophobic group of synthetic product:In other words, when Chain spacers were invariable, Researchs showed that critical micelle concentration of synthetic products would be gradually decreased with the total length of hydrophobic chain growthing. As far as surface tension was concerned, we found that surface tension of asymmetric Gemini surfactant of the type of quaternary Ammonium Salts were reduced the faster than that of symmetrical Gemini surfactant of the type of quaternary Ammonium Salts.