Synthesis And Application Of N-phenyl Maleimide

N-phenyl maleimide,1-Phenyl-1H-pyrrole-2,5-dione,N-phenylmaleic imide,Maleimidobenzene is abbreviated NPMI or N-PMI,pale-yellow aciform crystals.The melting point is 88～92℃.NPMI is a kind of heat resisting organic monomer,and can increase material thermostability by raising intemal rotation resistance of macromolecular,using its special molecular struture.NPMI is mainly used as heat resisting modifier today,and can effectively improve heat resistance,processibility, compatibility of polymers and impact properties.NPMI is also used as crosslinking agent and heat resisting agent of PS,PMMA,PP and PVC.The report on using to modify,thermosetting resins and glass fibre reinforced plastics(GFRP)have not been detected.In this paper the writer summarizes application and studies of N-phenyl maleimide,mainly consisting of heat resisting modifier,optical materials,medicine intermediate,and antifouling compound etc.,and study evolutions on copolymerization with vinyl monomers,mainly consisting of alternating copolymerization,terpolymerization and other copolymerization etc.,and study evolutions on flame-resisting N-phenyl maleimide,including application and synthesis etc.,and the advantages and disadvantages of different synthesis,involving one step way,deacidification method,esterification method,azeotropy method and acetic anhydride method etc..The preparation of N-phenyl maleimide(NPMI)is studied in this paper.Using aniline and maleic anhydride as raw materials,and mixture of xylene and DMF as solvent,and benzoquinone as polymerization inhibitor,N-phenyl maleimide is synthesized through the acetic anhydride method(one step way).The product is characterized by FTIR(Fourier transform infrared spectroscopy),GC(Gas Chromatography)and NMR(Nuclear Magnetic Resonance).The application of N-phenyl maleimide is studied in this paper also,including copolymerization with styrene,modifycation with unsaturated polyester resins and FRP.The modified materials are characterized by heat-resistant properties,mechanical behaviours and microstructures.The results are specialized as follows. 1.The appropriate reaction conditions of synthesis of NPMI are that,the mole ratio of raw material(maleic anhydride;aniline)is 1∶1.2,and the ratio of mix-solvent (xylene;DMF)is 20∶1,and the temperature of the first-step reaction is 40～50℃,and the optimum conditions of the second-step reaction are 135℃and 2h.The composite catalyzer(acid catalyze)can effectively catalyze cyclize reaction on the sysnthesis of N-phenyl maleimide.The yield of NPMI arrives at 90%,and the purity is 98.15%. The superfluous maleic anhydride can be reclaimed by extraction.The extraction temperature is 80℃,and the dosage of water for extraction is 5 times to the quantity of maleic anhydride.The reclaime rate of maleic anhydride arrives at 80%.2.The solubility curve of NPMI in styrene is linear relationship;5～350℃,S= 0.01t and 40～60℃,S=0.42+0.022(t-40).The appropriate reaction conditions of precipitation polymerization Of NPMI and styrene are that,[BPO]=3×10^-3mol/L, [NPMI+St]= 0.7mol/L,and the optimum conditions of copolymerization are 80℃and 5h.The fractional conversion of copolymer arrives at 98%.The reaction is in progress of alternating copolymerization.3.The heat resistance properties of the modified UP resin casts are improved significantly.The heat-resistant temperature increases 4～5℃when the dosage of NPMI is 2～8%.The heat-resistant temperature of modified FRP increases 7～8℃average.4.The maximum tensile strength of modified UP resin cast increases 5.5%, reaches 67.3MPa and the maximum tensile strength of modified FRP increases 6%, reaches 261MPa while the usage of NPMI is 2%.The maximum impact strength of modified UP resin cast increases 23%,and the maximum impact strength of modified FRP increases 5%,reaches 310KJ/m² reaches 8.6KJ/m² when the usage of NPMI is 6%.5.The optimum conditions for synthesizing the polyester cured matting powder coating by introducing N-phenyl maleimide are determined,comprising controlling glasstransition temperature of the resin at 70℃and GMA content at 20%.The adhesion and lustrousness of the matting powder coating are 1 level and 4% respectively.6.The geometric configurations of NPMI and MAH are simulated and computed. By contrasting the charge distribution of NPMI and MAH monomers,the influences of benzene ring group and N atom on C=C act insidiously,but on H atom,O atom,C atom of C-C act some distinctness.It is proved that the calculated values of IR and ¹H NMR of N-phenyl maleimide by Gaussian program are in accord with experiment values approximately.