Study On The Influence Of Fluoride-containing Groups On The Properties Of Materials

Fluorine element?fluorine,F?is a kind of non-metallic chemical element,which is widely distributed in nature.Based on the special structure of fluorine atoms,organic fluorinated compounds and fluoropolymers exhibit excellent physical and chemical properties.The bond energy of fluoro-carbon bond is very high.In combination with the shielding and protection effect of fluorine atoms on carbon atoms,the introduction of fluorine atoms or fluorine-containing groups into polymers can significantly improve their some properties,such as thermal stability,chemical corrosion resistance,hydrophobicity/hydrophobicity,oxidation resistance and insulation.In addition,fluoride atoms have very strong electronegativity and smaller atomic radius.The introduction of fluorine atoms into drug molecules can achieve fine-tuning and modification of molecular structure and improve the metabolic pathway and speed of molecules.At the same time,intermolecular hydrogen bonding can effectively prolong the interaction time of drug molecules,improve the bioavailability and selectivity of drug molecules.In the preparation of fluoropolymer,random copolymers of trifluoroethyl methacrylate?trifluoroethyl mathacrylate,FMA?and perfluorooctane ethyl acrylate?perfluoroalkyl ethyl actylates,TEAc-8?were prepared by solution radical polymerization.The structure and properties of the polymers were characterized by nuclear magnetic measurement?NMR?,infrared absorption spectrum?IR?,thermal gravimetric method?TGA?and differential scanning calorimetry?DSC?.The results show that the polymer has good thermal stability and film-forming properties.Finally,the organic/inorganic hybrid composite superhydrophobic coatings?water contact angle greater than 150°?were prepared based on the simple doping of nano-silica based on the lower T_g).In the second chapter,the light-responsive p-trifluoromethoxyazophenyl hexyl acrylate?p-trifluoromethoxy azophenyl hexyl acrylate,FAzo?functional monomer was firstly synthesized.A series of azo-containing binary random copolymers were prepared by copolymerization of these copolymers with FMA monomers in different molar ratios.The structure and photosensitivity of monomers and polymers were characterized by IR,NMR,UV-vis absorption spectroscopy.Then,the surface of cotton fabric was modified with copolymer solution as impregnation solution.The surface of the smart fabric showed a reversible super-hydrophilic/super-hydrophobic infiltration transition under the exposure of UV/visible light.At the same time,the light-responsive fabric surface coating also showed excellent chemical and mechanical stability after different pH solution impregnation tests?24h?,cyclic bending/folding/crimping/twisting and multiple washing tests.In addition,a selective exposure system is used to realize the reversible writing/erasure of different hyperinfiltrating groups on the surface of the fabric.In chapter 3,in order to introduce fluorine atoms into small molecular compounds,a series of aryl benzyl bromide substrates containing monofluoromethyl groups were synthesized.Bidentate nitrogen ligands of pyridine-oxazoline framework and aryl Bpin-Li salts with different substituted groups were used to construct monofluoromethyl chiral molecules using NiBr₂·DME as catalyst,DME as solvent and equivalent zinc bromide as additive agent.The results show that the addition of chiral ligands can assist in the formation of chiral centers,and the addition of zinc bromide can rapidly convert aryl Bpin-Li salts into highly active aryl zinc reagents,which can effectively promote the process of the reaction.Finally,a series of experiments were carried out to obtain diaryl compounds with chiral center of monofluoromethyl in good yield.