Synthesis And Properties Of Perfluoropolyether Amidyl Propyl Tertiary Amine Derivatives

The perfluorooctane sulfonates?PFOS?and salts perfluorooctanoate?PFOA?are probably the most common used fluorinated surfactants.However,those long-chain perfluoroalkyl perfluorinated surfactants had been listed as persistent organic pollutants?POPs?,for its hardly biodegradable in the environment.Perfluoropolyether surfactant is a new-type important biodegradable fluorinated surfactants,which can be used as substitute for the perfluorinated long-chain surfactants.The PFPE-A,PFPE-B and PFPE-C were synthesized,and their physicochemical properties,application performance and the mixture of PFPE-A with K12 were investigated systematically in this thesis.The main research work is as follows:?1?The three new perfluoropolyether surfactants were obtained from perfluoropolyether fluorine?PFPF?through amidation and quaternylation reaction.The chemical structure of raw material?PFPF?and products?PFPE-A,PFPE-B,PFPE-C?were confirmed by FT-IR,¹H NMR and ¹⁹F NMR,which revealed that the products were identical to the target molecule.?2?The thermal stability,surface activities,adsorption abilities,aggregation behaviors were preliminarily studied.The results showed that thermal decomposition temperature of the three perfluoropolyether surfactants remained in 200²50?;Each of PFPE-A,PFPE-B and PFPE-C exhibit high surface activity,all of which can make the surface tension of water drop from 72.0 mN/m to 17 mN/m,even more the critical micelle concentration?cmc?of PFPE-C was 2.40×10^-5 mol/L.Through the calculation of thermodynamic function of micellization by Gibbs formula,it was found that the micellization process was spontaneous exothermic and entropy driven,and their aggregation behavior showed that they can spontaneously form a good stable vesicle structure at the concentration of 3000 mg/L.The adsorption mechanism of these three perfluorinated polyether surfactants in aqueous solution belonged to hybrid control adsorption by dynamic surface tension.?3?The wettability and foam properties of three compounds were preliminarily studied,and work on softener of PFPE-A was carried out by comparing with D1821.The results showed the three kinds of perfluoropolyether surfactants had strong wetting properties.At the concentration of 1 mmol/L,the paraffin membrane and polytetrafluoroethylene film were entirely covered with PFPE-A solution.By comparing the PFPE-A with D1821,it is found that PFPE-A is better than D1821 in addition to rewettability force,but does not have as much white,flexible,antistatic as D1821.Therefore,PFPE-A is not suitable for fabric softeners.?4?The physicochemical properties of PFPE-A/K12 mixture aqueous solution were discussed.The experimental results show that the PFPE-A/K12 mixture system has a good synergistic effect on the efficiency of reducing the surface tension.Even a small amount of PFPE-A in the K12 solution can obviously reduce the surface tension of the K12 solution.In the mixture system,the higher the content of PFPE-A is,the greater the rate of reducing the surface tension and the combination of the compound system.The wetting performance of the system is stronger.