The Synthesis And Properties Of Novel Cationic Surfactant Dodecyl Dimethyl Hydroxyethyl Ammonium Bromide

A new type cationic surfucant– dodecyl methyl dihydroxyethyl ammonium bro- ide(DBMAC)was syhthesized from N-Methyldiethanolamine and bromododecane in this study. The structure of the product was characterized with IR and 1 H NMR.Through RSM, the mathematical relational model between conversion rate and factors was established, and the microwave synthesis technique of dodecyl methyl dihydroxyethyl ammonium Bromide was optimized. The results showed that the most suitable condition for the reaction were as follow as: solvent volume was 6.9 mL,the microwave irradiation power was 636 W,the radiation time was 23min,and the yield reached up to 92.18%.Compared with traditional method,the time of synthesis was only 5.48%.The most suitable condition for the synthesis of dihydroxyethylbenzylmethyl ammonium Bromide was optimized. The results showed as follow as: the temperature was 90℃,the radiation time was 150min,the mole ratio was 1:1, the rotate speed was 200 r·min-1,and the yield reached up to 90.2%. According to the best reaction conditions amplification experiment was made.The amplify of synihesis course was studied,The solvents of influence of temperature grads and concentration grads,and reaction periods etc.Through determination and study on the surface properties and application performance of DBMAC, the CMC was 1.67×10-4mol·L-1, surface tension was 24.2N·m-1, Krafft Point was below 0℃and melting point of the product was 111.2~111.9℃. At the same time, it showed good solubilization and deuto-wetting property of the surfactant. Its emulsification property, foaming power and softening property were also quite well; besides the effect on fabric whiteness was lower.The reaction were studied under microwave irradiation and conventional heating on the different boiling temperature point of the solvents. The kinetic parameters were obtained and analysis the effect of microwave.Results show that,the effect of microwave did not alter order of reaction. The activation energy is 41.44kJ /mol under microwave irradiation.while the actactivation energy is 61.21kJ /mol under normal heating. The new concep t of microwave devotion△(-rA) for chemical reaction was proposed in this paper. It is the increment of the reaction rate of microwave reaction and traditional reaction. The experimental result indicated that in the same temperature, the lower reactant concentration, the higher of the microwave devotionΔ(-rA). And the lower of temperature, the higher of the microwave devotionΔ( - rA ).