Preparation Of Cyanate Ester And Its Outgas Effect Under Irradiation

Cyanate Ester is a kind of high-performance polymers, and the prospects ofapplication in space technology are broad. In this thesis，pure cyanate ester EP00andmodified cyanate ester EP05by5wt%epoxy E51in specified process was prepared.Outgassing features of the materials before and after irradiation was studied by SpaceSynergistic Irradiation Equipment and High-Energy Electron Accelerator. Furthermore,the mechanism of outgassing changing and the structure changing after irradiation wasanalyzed. Essential data and theoretical support were given for the application ofcyanate ester in space application.Based on the study of curing reaction kinetics, and referred to the domestic andoverseas current curing process, plates of EP00and EP05were prepared. Result showsthat the elasticity modulus of modified cyanate ester EP05was improved by24.85%.Under the condition of QJ1558-88Vacuum Material Volatile Performance TestMethods, the Total Mass Loss （TML） of EP00and EP05is respectively0.499%and0.430%, much smaller than the outgassing criteria of space materials.Test shows, under the condition of electron irradiation, the mass loss in unit area ofcyanate ester is increasing with the increase of electron fluence, and the higher energyelectrons have a greater impact. Because of the low energy of150keV electrons, theeffects on vacuum outgassing are limited. The mass loss of EP00and EP05was reducedby9.2%and7.7%respectively after irradiation of7.3×10¹⁵e/cm²than that in originalstate. After irradiation of1MeV electron, the mass loss of EP00and EP05was reducedby34.1%and51.2%respectively when the fluence reached3×10¹⁵e/cm², no obviousimpact was observed when the fluence continue to increase.In the use of In Situ Mass Spectrometry, Electron Paramagnetic Resonance （EPR）,Fourier Transform Infrared Spectroscopy （FT-IR）, Differential Scanning Calorimeter（DSC）, Scanning Electron Microscope （SEM）, etc., the structure changing of cyanateester and mechanism of1MeV electron irradiation influence on outgassing was studied.The result indicates that cyanate ester cross-linked during the irradiation, the degree ofcure increased in this process. This is the primary cause of outgassing decrease. Someof the methyl on the side chain will fall off at the same time, but the number of fallenmethyl is small, along with that the net structure is against the diffuse of micro molecule,no considerable micro molecule gases observed during irradiation.By the use of space charged particle energy spectrum equivalent simulation testmethod,8years synergistic radiation simulation of the two materials in geosynchron-ous orbit （GEO） was proceed. It turned out that after the synergistic radiation, the massloss of EP00and EP05was0.471mg/cm²and0.216mg/cm², significantly reduced after irradiation, indicates that cyanate ester has good outgassing stability in space vacuumand irradiation environment.