Synthesis And Carboxyl Functionalization Of Poly(aryl Ether)resin Based On Phenolphthalin

Recently,functional polymer materials are constantly emerging in the fields of optics,electricity,magnetism and shows a very bright application prospect.Poly（aryl ether）resin（PAEs）has been widely used in functional polymer because of its excellent comprehensive properties.In many applications,dielectric poly（aryl ether）polymer for advanced energy storage technology and fluorescent poly（aryl ether）material for fluorescent display technology are two important research directions.In this thesis,poly（aryl ether）resins based on phenolphthalin（PAEs-COOH）were prepared by a convenient synthesis method.A series of functionalized PAEs were prepared by chemical modification of the carboxyl group of the side chain of the polymer.The dielectric and fluorescent properties of these functionalized PAEs were further studied.Firstly,three kinds of poly（aryl ether）resins with carboxyl side groups were prepared by nucleophilic substitution reaction of phenolphthalin with different aromatic dihalide.They are PEEK-COOH,PAEN-COOH and PAES-COOH.The related flexible films with uniform thickness（about 30μm）and good transparency were prepared by solution casting.The tensile strength of these films is about 35～55 MPa,and the elongation at break is between 6%～8%.The results of thermal analysis showed that the polymer had high heat resistance.Comparing the dielectric properties of the three polymers,it was found that under the same conditions,the dielectric constant of PAEN-COOH was the highest,and the dielectric loss of PEEK-COOH was the lowest.Furthermore,PEEK-COOH showed the best energy storage efficiency and good temperature stability.Then,based on the above-mentioned polymer PAEs-COOH,two kinds of functional poly（aryl ether）dielectrics（PEEK-SO₂,PAEN-SO₂,PAES-SO₂;PEEK-CN,PAEN-CN,PAES-CN）were prepared by introducing polar groups into carboxyl side groups with two steps.All the six kinds of polymer films have good mechanical properties and heat resistance,and PAES series have the highest T_g（～199℃）.The dielectric property showed that the dielectric constant increased about 20%on average after introducing dipoles.In addition,these dielectrics have a wide operating temperature range.During the test,PAEN-CN showed the highest energy storage density of 8.6 J/cm³（at 200 Hz and 650 MV/m）and releasing efficiency of 94.3%.In contrast,PEEK series has better high temperature energy storage performance.Finally,poly（ether ether ketone）copolymer with carboxyl group in side chain（PEEK-CP-COOH）was prepared by copolymerization of phenolphthalein and phenolphthalin with 4,4′-difluorobenzene ketone.Europium ion and terbium ion were used as central ions to bridge the molecular chain of PEEK with carboxyl group to prepare bonded rare earth polymer fluorescent materials.The effects of molar ratio of polymer ligand to rare earth metal ion on the properties of the composites were systematically studied by UV-vis absorption,optical transmittance and fluorescence emission spectra.The results showed that when the molar ratio is 6:1,the fluorescent film had excellent light transmittance and fluorescence emission intensity.Subsequently,the fluorescence emission intensity,fluorescence lifetime and quantum yield of fluorescent films were studied.In addition,the tensile test and TGA test results showed that these films had good mechanical properties and thermal stability.