The Synthesis And Performance Research Of Novel Quaternary Ammonium Salt Asphalt Emulsifiers

A new cationic asphalt emulsifier of N,N-dimethyl-N-(3-(N’,N’-dimethyl amido)-2-hydroxy propyl)-coconut oil amide propyl-1-ammonium chloride was synthesized by two steps reaction of coconut oil acyl propyl dimethyl tertiary amine (PKO), epoxy chloropropane and dimethylamine. The chemical structure of the key intermediate of N,N-dimethyl-N-(ethylene oxide-2-methylene)-coconut oil amide propyl-1-ammonium chloride was confirmed by FTIR, H1 NMR and elemental analysis. The optimum reaction condition of first step was obtained by single factor analysis:reaction time 5h, reaction temperature 50℃, feedstock mole ratio of epoxy chloropropane to PKO 1.05. The reaction yield reached 82.15% and the epoxy value reached 40.39% at the optimum conditions. All of the two synthesis steps were monitored by online FTIR technique. The by-product was detected by the online FTIR analysis. Based upon all these experiment data, a reasonable reaction mechanism was proposed. The CMC of the emulsifier has a lower value of 7.8×10-2 mol/L. The surface tension at CMC is 24.57mN/m. The emulsifier exhibits satisfactory emulsification. The prepared bituminous emulsion showed higher storage stability. The emulsifier belongs to medium-set asphalt emulsifier.A symmetrical Gemini cationic asphalt emulsifier of 1,3-bis(3’-coconut oil amide propyl-dimethyl ammonium chloride)-2-hydroxy propane was synthesized by two steps reaction of coconut oil acyl propyl dimethyl tertiary amine (PKO), epoxy chloropropane and hydrochloric acid. The structure of the product was confirmed by FTIR, H1 NMR and elemental analysis. The optimum reaction condition was obtained by single factor analysis:reaction time 6h, reaction temperature 80℃, feedstock mole ratio of epoxy chloropropane to PKO 1:2. The reaction yield reached 54.01% at the optimum conditions. The synthesis process of 1,3-bis(3’-coconut oil amide propyl-dimethyl ammonium chloride)-2-hydroxy propane was monitored by online FTIR technique. Based upon the experiment data, a reasonable reaction mechanism was proposed for the reaction. The CMC of the emulsifier has a lower value of 3.65×10-2 mol/L. The surface tension at CMC is 27.43mN/m. The emulsifier exhibits satisfactory emulsification. The prepared bituminous emulsion showed higher storage stability. The emulsifier belongs to rapid-set asphalt emulsifier.A series of three novel biscationic asphalt emulsifiers were synthesized by two steps reaction of N-tallow-1,3-diaminopropane, methyl acrylate, sodium hydroxide and chloroacetic acid. The structure of the product was confirmed by FTIR, H1 NMR and elemental analysis. The emulsifier exhibits satisfactory emulsification. The prepared bituminous emulsion showed higher storage stability. The emulsifier belongs to medium-set and slow-set asphalt emulsifier.