Study On Synthesis Of Gemini Surfactants

A new generation of surfactants, Gemini surfactant has attracted widely attention in some industrial fields and academic research institutions. The Gemini surfactant molecule has two hydrophobic groups and two hydrophilic groups, which connected by a sPacer.By this way, the separation approach between the polar headgroups within Gemini surfactants is strongly decreased when they aggregate and thus the surface activity is greatly enhanced. There are many reports of its syntheses but there are only some products in the application of industry. A studay on synthesis of gemini surfactant which is easily degradable industrial and friendly to the environment has been done in this thesis. A new analytical method of ester rate determination was set up;The culling and syntheses of the catalysts ,used in esterification reaction,were studied;And the optimumreaction conditions were obtained,the reasults are got as follows:The characterization of esterification reactions is the determination of maleic anhydride's ester rate.According to the methods of saponification value and acid value's determination, a new analytical method of ester rate determination was set up;The phosphotungstuic acid supported with active carbon was the best catalyst though the culling of the catalysts for esterification reactions .And the method of preparation was got as follows:reflux time is 6h, dry and activation temperature was 180℃, dry time is 8h.There are two different routes in the synthesis of maleic acid diester,and the first route was optimized in this thesie. The optimum reaction condition of the maleic acid monoester's preparation was obtained as followsm maleic anhydnde:nethyiene glycol=2.10:l,the dosage of catalyst was 1.0%(wt%),with the solvent of acetone. The optimum reaction condition of maleic acid diester's preparation was got as follows: n lauryl alcohol:n maleic acid monoester =2.10:1, reaction temperaure was between 150℃ to 160℃, vacuum degree was about 0.09MPa, reaction time was 8h,the dosage of catalyst was 0.1%(wt).The sulfonation reaction condition was set up as followsm maieic acid diester:n NaSO₃=1:2.20,reaction temPature was between 95℃ to 100℃,reaction time was 6h,and the dosage of phase transfer catalyst was 1.5%...