Synthesis Of Photosensitive Fluorinated Polyimides And Its Application

With the rapid development of three industries of the “information,energy and materials”,the demand for high-performance polymeric materials is increasing day by day.Polyimide(PI),as an important class of high-performance material,has been widely implemented in microelectronic,aerospace,automobile,photovoltaic energy and other fields due to its outstanding thermal,mechanical,electrical and other properties.However,PI generally suffers from the poor solubility,high melting temperature,low transparency,and high curing temperature,complex film-forming process,serious energy consumption and so on,which greatly posed limitation on its extensive applications.Therefore,how to ensure the excellent performances and design of novel soluble transparent polyimide structure,simplify the filmforming process,prepare multi-functional high-performance polyimide materials and broaden the application fields,it will be a significant task for promoting industrial development and technological progress.In view of this,a series of photosensitive polyimides were synthesized by fluorinated monomer,and the UV-cured coatings and films with good performances were prepared by UVcuring technology.The relationship between the structure and properties was studied,as well as its application in microelectronics.The detailed contents are as follows:1.A series of photosensitive fluorinated polyimides(GFPIs)containing different carboncarbon double-bonds contents were synthesized based on 4,4'-(hexafluoroisopropylidene)diphthalic anhydride(6FpDA),4,4'-(hexafluoroisopropylidene)dianiline(6FDA),4-aminobenzoic acid(ABA)and glycidyl methacrylate(GMA).The structure and properties of GFPIs were characterized by Fourier transform infrared spectroscopy(FT-IR),proton nuclear magnetic resonance(1H-NMR),gel permeation chromatography(GPC),X-ray diffraction(XRD),differential scanning calorimetry(DSC),solubility test and so on.It was determined that all GFPIs exhibited the amorphous phase and excellent solubility.Then,the fluorinated polyimide UV-cured coatings(GFPIs)were prepared by UV-curing technology,and the performances were evaluated by real-time fourier transform infrared(RTIR),thermogravimetric analysis(TGA),UV-Vis spectroscopy(UV-Vis),water absorption test and so on.Results showed that these coatings possessed favorable double-bond conversion,excellent thermal stability,higher optical transparency and lower moisture uptakes,and could be used as buffer layer and high-temperature resistant coatings in the microelectronics industry.Moreover,the polymer GFPIs have a good application in the photoresist,and the resolution can be up to 50 ?m by coating formulation optimization and scanning electron microscopy(SEM)analysis.2.A series of photosensitive bio-based polyimides(BGPIs)containing different bio-based contents were synthesized based on diamine 6FpDA,bio-based diamine Priamine 1074,dianhydride 6FDA,ABA and GMA.The structure and properties of BGPIs were characterized by attenuated total internal reflectance fourier transform infrared spectroscopy(ATR-FTIR),1H-NMR,GPC,XRD,DSC,solubility test and so on.It was determined that all BGPIs exhibited the amorphous phase,excellent solubility and high content of biomass up to 48.9%.Then,the bio-based polyimide UV-cured coatings(BGPIs)were prepared by UV-curing technology,and the performances were evaluated by RTIR,TGA,UV-Vis,water contact angle test,water absorption test and so on.Results showed that these coatings possessed satisfactory crosslinking density,higher adhesion,lower water uptakes,outstanding optical transparency,and fairly favorable thermal stability,the initial decomposition temperature is above 400?.They could be used as bio-based high-temperature resistant coatings in the microelectronics field.In addition,the polymer BGPIs have a good application in the photoresist,and the resolution can be up to 45 ?m by coating formulation optimization and SEM analysis.3.The amino-functionalized graphene AFGO was synthesized by the modification of diazonium salt on the surface of reduced graphene.The structure and properties of graphene were characterized by ATR-FTIR,XRD,TGA,Raman spectroscope(Raman),X-ray photoelectron spectroscopy(XPS),Transmission electron microscopy(TEM)and so on.It was determined that AFGO exhibited excellent dispersibility and high amino surface modification rate up to 9%.Then,a series of photosensitive polyimide/graphene composite materials containing different AFGO additions were synthesized based on 4,4'-diaminodiphenyl ether(ODA),3,5-diaminobenzoic acid(DABA),dianhydride 6FDA,AFGO and GMA.The polyimide/graphene UV-cured composite films(GPI/AFGOs)were prepared by UV-curing technology,and the effects of AFGO additions on performances were evaluated by RTIR,SEM,TGA,electronic tensile tester,ultrahigh resistance tester,water absorption test and water contact angle.Results showed that the thermal properties,conductivity,water-resistance and hydrophobicity of the composite film GPI/AFGOs have been improved remarkably with the increase of AFGO additions.Especially their mechanical properties,with 1.00 wt% AFGO loading,the tensile strength and elongation at break can reach the maximum(108.7 MPa and 46.4%),increased by 102.8% and 354.9%,respectively.The enhanced films could be considered as potential candidates for antistatic flexible films in the microelectronics industry.