| With the rapid development of the electronic communication industry and the aviation industry,higher requirements for the materials have been requested by both of the two kinds of industry.The commonly used epoxy resins cannot meet the requirements of high-performance electronic communication equipment due to their poor temperature resistance,high brittleness and expansion coefficient.Therefore,the scholars at home and abroad have conducted extensive and in-depth research on the high-performance matrix resins.The bismaleimide/cyanate blended resin systems are a kind of high-performance matrix resins that possess great application prospects and have attracted much attentions in this field.However,due to the secrecy of technology,such resins are still mainly imported.In addition,the current research results cannot fully reflect the excellent performance of the resin in all aspects.In this paper,a variety of modification methods are used to modify the BMI/CE blended resin system.The preparation of three kinds of resin systems are presented in this paper and their performances are investigated by various tests.Firstly,a high-performance thermoplastic resin polyetherimide(PEI)is used to modify the CE,and the modified cyanate resin systems are prepared.In this process,the influence of PEI content on the performance of the modified cyanate resin system is explored.It is revealed that adding appropriate PEI can effectively improve the toughness of the resin system while the thermal stability and the glass transition temperature(Tg)are maintained;and the dielectric properties have been improved to a certain extent.When the amount of PEI is 10 parts,the resin system CE-10 will process the best performance.Its tensile strength is 82.1MPa,the elongation at break reaches 4.1%,and the impact strength is 14.5kJ/m~2,compared with the cyanate resin without PEI it has increased by 20.4%,46%and 8.2%respectively.The dielectric constant is 2.85 and the dielectric loss is 0.0069.Secondly,the N,N?-4,4?-diphenylmethane bismaleimide/diallyl bisphenol A(BDM/DABPA)resins with different molar ratios are blended with modified cyanate resin system CE-10 to prepare three series of BDM/DABPA/CE-10 blended resin.The differential scanning calorimeter(DSC),infrared spectroscopy(FTIR)and dynamic mechanical analysis(DMA)are used to study the curing mechanism of the blended resin A3.Through the DMA,DSC curves and the FTIR spectrum analysis,it is found that the curing mechanism of the A3 resin is more complicated with three kinds of reaction which are the"Ene"reaction and the"Diels-Alder"reaction between BDM and DAPBA,BDM self-polymerization and the DAPBA-catalyzed CE resin self-polymerization respectively.And finally a molecularly homogeneous cross-linked network structure is formed.The performance test results show that all the blended resins have excellent thermal stability,high Tg,excellent mechanical properties,good dielectric properties and low water absorption,which can meet the requirements of the high-performance printed circuit board as a matrix resin.Finally,the N,N-(4-methyl-1,3-phenylene)bismaleimide(MPDM)is synthesized.The plan is supposed to mix it with BDM and DABPA to prepare the MPDM/BDM/DAPBA resin,and then blend with the modified cyanate ester resin system to obtain a modified bismaleimide/cyanate ester blended resin system,and investigate whether the performance of the resin can meet the requirements of high-performance printed circuit boards.However,affected by the new coronavirus pneumonia epidemic,this part has only completed the synthesis of MPDM.Its structure has been confirmed by the FTIR,NMR carbon spectroscopy and hydrogen spectroscopy.The purity of the synthesized MPDM is 96.30%which is measured by the high-performance liquid chromatography. |
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