| In this paper, a new type of cyanate/epoxy foam w ith bisphe nol- A dicyanate ester prepolymer and diglyc idyl ether of b ispheno l- A(BADC y/DGEBA) has been successfully prepared through a two-step process. Effects of the ratio of epoxy resin, densit y and carbon nanot ubes content on the structures and properties of cyanate/epoxy foams were primar ily studied. Also studied the effect of t he carbon nanotubes and carbonyl iron powder on the properties of cyanate/epoxy foa m absorbing.The mo lecular structure and cell structure of the cyanate/epoxy foam were characterized by FTIR and SEM, respective ly; t he glass trans it ion te mperature were characterized by DMA and DSC, respectively.The t herma l stability o f the cya nate/epoxy foa ms were characterized by TG; compress properties of t he cyanate/epoxy foams were characterized by e lectronic universaltesting machine. The d ielectr ic propertie of cyanate/epoxy foam was measured using D ie lectr ic spectrometer. Using the vector network analyzer test the absorbing perfor mance of cyanate ester/epoxy foam.The results show t hat the cyanate/epoxy foam cured comp letely, and the characterist ic peak of the-OCN group(2272-2236 cm-1) and epoxide group(913 cm-1) are not observed on FTIR spectrum. The foam has relat ively unifor m closed cell and all the cells can be clearly observed and the cells are almost sphere. The foam has excellent t hermodynamic properties.The epoxy resin increases have no effect on the cell struct ure.C yanate/epoxy foam whic h have the more the ratio of epoxy resin exhib its better mechanica l properties and lower Tg; the densit y has no effects on glass trans it ion temperature, but wit h the increase of dens ity, the storage modulus of C E 60 cyanate/epoxy foa m increased, the compression strength increased fro m 0.507 MPa by the densit y of 0.103 g/cm3 to 0.507 MPa by the dens ity of 0.305 g/cm3 and the compression modulus increased from 15 MPa to 123 M Pa.The size of cell decreased from 220.8 μm to 141.7 μm. The die lectric constant and die lectric loss were also increased. Wit h the increasing content of C N Ts, the size of cell decreased first and then increased,the cell struct ure became fine first and then become bad and the compression propertie is a lso improved first and then decreased. The reflectivit y of cyanate/epoxy foam increases wit h he increasing content of CN Ts. The addit ion of 5% weight CN Ts could get a lowed eflectivit y of e lectro magnet ic wave and the wave- absorbing perfor mance is better. Wit h the increase of CN Ts, the C E 60 cyanate/epoxy foam absorbing performa nce increased, when the carbon nanotubes and carbonyl iron powder as the absorbing agent. The best comb inatio n of carbonyl iron powder and CN Ts are: 30% C IP+0.5% CN Ts,The absorption peak is-9.81 d B, The bandw idth are 0.53GHz(R<5d B) and 0GHz(R<10d B), respective ly;30% C IP+1% C N Ts, The absorption peak is- 17.09 d B, The bandwidt h are 0.80GHz(R<5dB) and 0.5GHz(R<10d B), respectively.. |
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