Advanced wave-transparent composites are the key materials for many cutting-edge industries including aviation and aerospace, which should have outstanding heat resistance, low dielectric constant and loss as well as good mechanical properties. A novel kind of high-performance wave-transparent composites based on surface-modified aluminum phosphate AlPO 4 (KH-550) and cyanate ester (CE) was first developed. The dielectric and dynamic mechanical properties of AlPO 4 (KH-550)/CE composites were investigated intensively. Results show that AlPO 4 (KH-550)/ CE composites have decreased dielectric loss and higher storage moduli than pure CE resin; in addition, the composites with suitable AlPO 4 (KH-550) concentration remain the outstanding thermal property and low dielectric constant of pure CE resin. The reasons attributing to these results are discussed from the effects of AlPO 4 (KH-550) on the key aspects such as morphology, curing mechanism, and interfacial adhesion of composites.

Thermodegradation behaviors of novel aluminum phosphate/cyanate ester (AlPO 4 (KH550)/CE) composites were studied in detail. Results show that thermodegradation behaviors and kinetic parameters of AlPO 4 (KH550)/CE composites are greatly dependent on the AlPO 4 (KH550) loading. The addition of AlPO 4 (KH550) into CE resin changes the thermodegradation mechanism (mainly at the temperature lower than 450 C) and degradation process from two steps to three steps. Comparing with CE resin, AlPO 4 (KH550)/CE composites have lower initial degradation temperature and greatly higher char yield. Besides, for each thermodegradation step, the more the AlPO 4 content, the smaller the activation energy value is. All reasons leading to these outcomes are investigated intensively.

Novel fiber-reinforced dicyanate of bisphenol A (BADCy)/poly (urea-formaldehyde) microcapsules filled with epoxy resins (MCEs) composites were prepared. The effects of MCEs with different content and diameter on the mechanical properties and the hot-wet resistance of the composites were discussed. The morphologies of composites were characterized using a scanning electron microscopy and optical microscopy. The dynamic mechanical property (DMA) of the composites was also evaluated. The results indicate that the appropriate addition of MCEs with various diameters can significantly improve the mechanical properties and the hot-wet resistance of fiber-reinforced BADCy composites. The fiber-reinforced BADCy/MCEs composites have lower glass transition temperature (Tg), compared with the fiber-reinforced BADCy composites without MCEs.