Synthesis And Property Study Of Cationic Surfactant And Application In Emulsified Asphalt

With the development of modern cities and the construction of comprehensive transportation systems,highway network structure tends to be perfect.Therefore,the regular maintenance and repair of the existing roads have become more and more important.Emulsified asphalt is the main material for pavement maintenance,originating from the fact that it has many advantages of construction at normal temperature,lower energy consumption,and less pollution of the environment.And the emulsifier is the key to affect the preparation and use of emulsified asphalt.In this dissertation,five different cationic surfactants were synthesized from epichlorohydrin,octadecyl dimethyl amine,fatty alcohol polyoxyethylene ether and epoxypropyl trimethyl ammonium chloride.Among them,A is an intermediate produced in the the first step.B is a single cationic emulsifier reacted by A and fatty alcohol polyoxyethylene ether(n),and when n is 5,9,15,the emulsifier is respectively B(5),B(9)and B(15).C is a double emulsifier produced in the third step.The structures of the prepared compounds were confirmed by IR,and the best synthetic route and reaction conditions were explored.At the same time,we focus on the influence of the polyethylene oxide units and cationic units on various surface properties of emulsifier and the properties of the emulsified asphalt.The bromophenol blue experiment was taken to prove the cationic of the surfactants,for it can change color from red to violet.The surface activities were analyzed deeply by surface tension,electrical conductivity and HLB.And the obtained results indicated that the electrical conductivity experiment showed similar CMC values to surface tension experiment.What is more,emulsifier B(5)has lower CMC value as result of fewer number of polyoxyethylene units,and emulsifier C has higher CMC since it has dual cationic structure.The HLB results showed an increased tendency following the increase of the polyoxyethylene units and the cationic units.Surfactant B(5),B(9),B(15)and C are applied to the preparation of emulsified asphalt,and we carried out the corresponding various performance experiment.The results showed that the structure of the emulsifier,quality,pH and external equipment conditions all have significantly influence on emulsified asphalt storage stability.The demulsification experiments results showed that the emulsifier C has more obvious effect of slow-cracking because of the molecular space steric effect and the role of the intermolecular hydrogen bond.