Synthesis And Interface Performance Of Poly (Ethylene Oxide)-Based Fluorinated Or Hybrid Amphiphilic Compounds

With polyethylene glycol（PEG）as the hydrophilic segment,a series of fluorinated Multibranched-Linear-Multibranched（MLM）polymers and covalent polyoxometalate（POM）hybrids based on covalent modification were synthesized,and their surface/interface behavior and application performance were also studied.In addition,a series of alkyl hybrid POM amphiphiles with Na⁺as counter cation was synthesized,and the influence of the alkyl segment on the surface activity of the hybrid POM was investigated.In the synthesis and application of fluorinated MLM polymer with PEG as hydrophilic segment,PEG and glycidol are used to obtain hyperbranched PEG-[PG]₂ via anionic ring-opening polymerization;then the macromolecular initiator PEG-[PG-Br]₂ is obtained via the reaction between PEG-[PG]₂ and dibromoisobutyryl bromide（BIBB）;using trifluoroethyl methacrylate（TFEMA）as the monomer,the fluorinated MLM polymer were synthesized via the atom transfer radical polymerization（ATRP）.The fluorinated MLM polymer with different hydrophilic properties can be obtained by changing the length of the PEG segment.Based on the characterization of FT-IR,¹H NMR,¹³C NMR,¹⁹F NMR,and GPC,the demulsification performance of fluorinated MLM polymer in model emulsion system was evaluated,and the effect of the dosage of polymer,settling time,temperature,and naphthenic compounds on the demulsification efficiency of MLM polymer was studied.The rheology and particle size distribution of the emulsion were characterized and analyzed,and the demulsification mechanism of the polymer in the emulsion was discussed.The optimum demulsifying mass concentration of PEG-[PG-PTFEMA]₂ series was200mg/L,and the optimum demulsifier was PEG4000-[PG-Br]₂ with medium HLB value.PEG-[PG-PTFEMA]₂ can significantly reduce the interfacial tension of n-octane/sodium naphthenate aqueous solution.The polymer PEG4000-[PG-Br]₂ with mediumPEG chain length can reduce the interfacial tension from 39m N/m to about 16m N/m.The hydrophobic properties of the fluorine groups in PEG-[PG-PTFEMA]₂ can effectively improve the diffusion rate of the polymer from the volume phase to the interface,and adsorb to the interface.The hydrophobic properties of the fluorine groups will repel the original interfacial active substances at the interface,resulting in the destruction of the interfacial membrane and accelerating the aggregation between the droplets,so as to achieve rapid demulsification.In the synthesis of POM hybrids with PEG as a hydrophilic segment,triethoxysilane was used to react with[PW₁₁O₃₉]^7-to prepare hybrid POMs with different alkyl lengths;with exchanging the counter cation to Na⁺by ion exchange,the solubility of alkyl POM hybrids is increased;the surface activity of the POM hybrids in aqueous solution was evaluated.Na₃（C₈-Si-POM）can significantly reduce the surface tension of water,and the₍（88）（8）can reach 36.83m N/m.The₍（88）（8） of Na₃(C₁₂-Si-POM)is 47.32m N/m,while Na₃(C₁₈-Si-POM)has little surface activity.Through dynamic surface tension analysis,the initial adsorption stage of Na₃（C_n-Si-POM）in the solution is controlled by diffusion,and the final stage is controlled by mixing process.On this basis,using polyethylene glycol monomethyl ether（mPEG）as the hydrophilic segment,triethoxysilane modified mPEG was prepared by allylation and hydrosilylation reaction.Using[PW₁₁O₃₉]^7-as inorganic part,a novel POM hybrid with PEG as hydrophilic segments was synthesized.The molecular structure was confirmed by FT-IR,¹H NMR,³¹P NMR and ²⁹Si NMR characterization.