Research On The Synthesis,charateristics Andapplication Of Di-linear Alkylated Diphenylmethane Sulfonate

This paper systematically studied the synthesis, characterization, and properties of the novel anionic gemini surfactant---DSDM ( Di-linear alkylated diphenylmethane sulfonate). Found out the optimum conditions of synthesis of DSDM, and the intermediate and final products were characterized and analyzed, the surface chemical properties of C12-DSDM and the interface tension of C14-DSDM and C16-DSDM were mainly determined and studied.With diphenylmethane and acyl chloride as raw materials, through the Friedel-Crafts acylation reaction for the synthesis of diacyl diphenylmethane, the mechanism of Friedel-Crafts acylation reaction was discussed, influences of three kinds of different solvents on the reaction conversion rate were studied , nitromethane was chose to as solvent for acylation reaction.The effects of reaction time, reaction temperature on the conversion rate were studied, we chose to react at room tempersture about 25 hours, the yield of the reaction is 91.1%, IR spectrum of the products were characterized. The second step of synthesis is the reduction of diacyl diphenylmethane, the diacyl diphenylmethane was deoxidated by two methods, the two mathods were Clemmensen reduction and Wollff-Kishner-Huang Minglong reduction, the mechanism of the two reactions were discussed. The effects of reaction time and catalyst amount on the Clemmensen reduction were studied, the amount of catalyst about 5 mg/0.1mol reactant and 8 hours' reaction time was chosed, and yield of the reaction is 89.2%. The products were analyzed by thin layer chromatography, we found out the best developing agent, the products were purified by column chromatography, and characterized by IR spectrum, 1H NMR spectrum. Orthogonal experimental L9(34)were designed, we found out the optimal conditions of Wollff-Kishner-Huang Minglong reduction were: reaction time is 4h, reaction temperature is 190℃, m(triethylene glycol):m(diacyl diphenylmethane )=3:1, n(hydrazine):n(diacyl diphenylmethane)=7:1. Experimental under the combination of experiment conditions verificated that the reaction product yield can reach 76.7%. The third step of syntheses is the sulfonation of the reduction product. The sulfonation reaction mechanism was discussed, chlorosulfonic acid was selected as sulfonating reagent, neutralized with 15% NaOH solution. The yield of the reaction is 90.7%, and the final products were characterized by IR spectrum and MS spectrum. It was found that the products are the target products.The Krafft point of C12-DSDM was determinated, it is less than 0℃, that shows its better water solubility. The surface tension of C12-DSDM was determinated by self assembly drop volumu device, the results indicated that the cmc andγcmc is 1.452 mmol·L-1å'Œ38.49 mN·m-1 at 25℃. The surface tension of C12-DSDM was also determinated at a series of different concentrations of NaCl, and at different temperatures, we calculated the correspondingΓmax, Amin, C20, pC20 andÏ€cmc and calculated the solution thermodynamics of micellization function, data show that the system of micelle formation process is entropy driven process. The foaming, emulsifying,wetting power were determinated, data show that these properties of C12-DSDM are poorer than LAS. But the stability of C12-DSDM in different electrolyte solution is better than LAS.The interfacial tension of C14-DSDM,C16-DSDM were determinated at different concentrations of NaCl, under different temperature and hardness, The interfacial tension of C14-DSDM,C16-DSDM are affected by temperature and hardness of the water. The interfacial tension of C14-DSDM is not affected by salinity,but the interfacial tension of of C16-DSDM is affected seriously by salinity. The mixed surfactant exhibits an ultra-low interfacial tension of 9.44×10-3mN/m.