Study On Synthesis Of Novel Arylalkyl Sulfonate Gemini Surfactants

Gemini surfactant represent a new class of surfactants, it is made up of two amphiphilicmoieties connected by a spacer group covalently. Special molecular structure may result thatGemini surfactant has excellent physical chemistry properties and can be widely used to traditionaland modern industry. In the work, we synthesized two new Gemini surfactants usingα-tetradeceneolefin sulfonic acid as raw material, which are methylnaphthalene-ditetradecane disulfonate andphene-ditetradecane disulfonate. Moreover, the reaction conditions, analysis method for calculationof the conversion rate of benzene and α-methylnaphthalene, the purification of the products,molecular structure and surface property were also studied primarily.Firstly, we studied on the composition of raw materialα-tetradecene olefin sulfonic acid andits change under heating condition at 150℃. It was found that the raw material are composed of21.7% of α-tetradecene olefin sulfonic acid and 76.8% of corresponding sultone. When the rawmaterial was heated, the sultone in the raw material will discompose and form new α-tetradeceneolefin sulfonic acid. This change may remarkably effact the amounts of -SO3-and C=C bond in thereaction system. For the reason, using two methods for calculation of the conversion rate inliteratures are difficult to obtain real conversion rate of benzene or methylanphthalene during thereaction. Basing on the remarkable difference of absorbance between benzene or methyl-anphthalene and its product, we developed four new ultraviolet spectrophotometric methods foranalysis of the conversion rate, these have been applied to study on the reaction conditions with asatisfying results. Secondly, an orthogonal experiment was used to research the reaction of α-tetradecene olefin sulfonic acid with methylanphthalene. It was found that reaction time,temperature and style of adding raw materials are main factors to the effect on the conversion rateof the reaction. Thirdly, we designed a new synthesis route of methylnaphthalenyl-ditetradecanedisulfonate and phenyl-ditetradecane disulfonate, called as "one step method". Lastly, a singlefactor experiment was ulteriorly used to optimize the reaction conditions. Under optimal conditions,α -tetradecene olefin sulfonic acid reacted with benzene and methylnaphthalene to formmethylnaphthalene-ditetradecane disulfonate and phene-ditetradecane disulfonate with theproductivity of 82.1% and 82.0%, respectively.After methylnaphthalene-ditetradecane disulfonate and phene-ditetradecane disulfonate werepurified, some technologies including ultraviolet spectrum(UV),infrared spectrum(IR) andEIS-/EIS+—MS were applied to confirmed their molecular structure. Moreover, some surfaceproperties of above two Gemini surfactants were researched, the result indicated that the cmc ofmethylnaphthalene-ditetradecane disulfonate and phene-ditetradecane disulfonate were 0.02 and0.17mM, and pC20 were 5.66 and 5.07, respectively,these datum show novel arylalkyl sulfonateGemini surfactants have very high surface active.