Design And Preparation Of Magnetic Responsive Hyperbranched Polyamide-amine Demulsifier And Its Demulsifying Behavior Research

The magnetic responsive hyperbranched polyamide-amine demulsifier not only has the demulsification property of polyamide-amine demulsifier,but also has the magnetic properties of magnetic nanoparticles.It has made up the defect of traditional demulsifier,and has the advantages of good demulsification effect,environmental protection and recyclability,so it has broad application prospect and development space.The synthetic route of magnetic responsive hyperbranched polyamide-amine demulsifier?M-G_n-PAMAM?was studied.First,a series of superparamagnetic Fe₃O₄nanoparticles were synthesized respectively using Fe?acac?₃,Fe Cl₂·4H₂O and Fe Cl₃·6H₂O as raw materials and oleic acid,sodium citrate and ethylenediamine as additive.The reaction conditions were optimized by orthogonal experiment.The structure,particle size,morphology and magnetization of the Fe₃O₄nanoparticles were analyzed by X-ray diffraction?XRD?,Fourier infrared spectroscopy?FTIR?,Nano-laser particle size distribution instrument,Transmission electron microscopy?TEM?,Vibrating sample magnetometer?VSM?,and the synthesis method of Fe₃O₄nanoparticles was screened,which provided the conditions for synthesis and demulsification and functionalization technology of the Fe₃O₄nanoparticles.Then M-G_n-PAMAM was synthesized by Michael addition reaction and amidation reaction and using Fe₃O₄,tetraethyl orthosilicate,3-aminopropyl triethoxysilane,methyl acrylate and ethylenediamine as raw materials.And M-G_n-PAMAM was synthesized by graft polymerization method,step by step synthesis method and ultrasonic assisted step by step synthesis method.The structure,particle size,morphology,magnetization and coated situation of the intermediate and target product of M-G_n-PAMAM were analyzed by X-ray diffraction?XRD?,Fourier infrared spectroscopy?FTIR?,Transmission electron microscopy?TEM?,Vibrating sample magnetometer?VSM?and Thermogravimetric analyzer?TGA?,and this is an innovative exploration for the development of demulsification functionalized magnetic materials.Finally,the demulsification performance of M-G_n-PAMAM synthesized by graft polymerization method and ultrasonic assisted step by step synthesis method were tested.Under different experimental conditions,the demulsification efficiency,circulation efficiency and so on of M-G_n-PAMAM were investigated,and the demulsification performance of M-G_n-PAMAM synthesized by different methods was compared in detail.The experimental results obtained are as follows:Optimal synthesis conditions of magnetic Fe₃O₄nanoparticles for demulsification:solvent-thermal method,sodium citrate as additive,ferric chloride/sodium acetate molar ratio1:10,ferric chloride/sodium citrate molar ratio 1:0.37,reaction temperature 200?,reaction time 10 h.The product Fe₃O₄nanoparticles are pure,crystalline and superparamagnetic.The morphology of Fe₃O₄nanoparticles is a near-spherical nanocluster with a large surface area,which is conducive to subsequent functionalization.Moreover,their water dispersion is relatively good,which guarantees the basic conditions for demulsification.M-G_n-PAMAM was synthesized by different methods,containing Fe₃O₄and with better crystal morphology.The Si O₂layer and PAMAM dendritic macromolecules were successfully modified on the surface of Fe₃O₄nanoparticles.At the same time,magnetic nanoparticles modified by PAMAM dendritic macromolecules have magnetic response characteristics,which creates conditions for recycling.The synthetic product is consistent with the intended design.The maximum oil removal rate of G_n-PAMAM was 90.49%,the maximum oil removal rate of M-G_n-PAMAM synthesized by graft polymerization method was 93.87%,the maximum oil removal rate of M-G_n-PAMAM synthesized by ultrasonic assisted step by step synthesis method was 94.84%,and the demulsification effect of magnetic demulsifier M-G_n-PAMAM was better than G_n-PAMAM.Under the condition of p H 4?10,M-G_n-PAMAM can achieve demulsification of crude oil emulsion,with better oil removal rate and wider application range.M-G_n-PAMAM not only has excellent demulsification performance,but also has good recoverability.After 9 cycles,the oil removal rate of M-G_n-PAMAM synthesized by graft polymerization method was still higher than 85%;After 9 cycles,the oil removal rate of M-G_n-PAMAM synthesized by ultrasonic assisted step by step synthesis method was still higher than 78%.G_n-PAMAM and M-G_n-PAMAM promote demulsification of crude oil emulsion,and the final emulsion gives out almost the same amount of water.In conclusion,M-G_n-PAMAM has excellent demulsification performance.Assisted by magnetic field,the demulsification efficiency of emulsion is improved,the recovery and reuse of demulsifier are realized,and the demulsification cost is reduced.It has important application value to solve the practical production problem and enrich demulsification technology system.