The Synthesis And Performance Study On N'-Long Chains Alkyl Groups-N,N-Dialkyl Groups Acetamidines

CO₂ switchable surfactants is a kind of surfactants that can realize the emulsification and demulsification reversiblely under the trigger of CO₂/N₂.They have the advantage of protecting environment and recycling,it is significative to study the synthesis and performance of CO₂ switchable surfactants.This ariticle studied the reaction path of Scoggins Procedure to synthesize the amidines compounds as CO₂ switchable surfactants and evidenced that the Scoggins Procedure is consecutive reaction.The N'-long chain alkyl group-O-dimethylacetimi dates?OMAI?was got from the reaction between N'-long chains alkly group-N,N-dimethylacetamidines?DMAA?with methanol.It was better for the formation of alkyl acetamidines under the conditions of the raw ratio of N,N-dimethyl acetamide dimethyl acetal?NNDADA?and primary amines?PA?was 1.2:1,the reaction temperature was about 68 ^oC,the reaction time is 10 min,we synthesized a series of N'-long chains alkly group-N,N-dimethylacetamidines(C₁₂-₁₈-DMAA)successfully.We also synthesized classes of N'-long chain alkyl group-O-dimethylacetimidates(C₁₂-₁₈-OMAI)through prolonging reaction time,raising the reaction temperature and changing the variety of solvents.On this basis,the new CO₂ switchable surfactants N'-long chain alkyl group-N,N-diethylacetamidines?DEAA?were synthesized from the reaction between acetimidates with diethylamine.We also studied the influencing factor on reaction time and the amount of diethylamine.The DEAA presented an excellent CO₂/N₂switchability and had the ability to emulsify the oil-water mixture.The temperature'effect on the C₁₂-₁₈-DMAA protonation,C₁₂-₁₈-DMAAB deprotonation and the comparation of emulsification was investigated.It was found that the C₁₈-DMAAB own the strongest emulsify ability.In addition to this,the analysis of HPLC about C₁₂-₁₈-DMAA was establized.