Polyimide/silica nanoparticle-modified epoxy resin and kevlar/glass fiber-reinforced polymer matrix composites for potential application in commercial aircraft radomes

An aircraft radome must enable radio signals carrying crucial weather data to a radar antenna to pass through it with minimal losses/reflections. This can be assured by fabricating the radome with a resin possessing a low dielectric constant. Nevertheless, most resins currently utilized in the fabrication of aircraft radomes such as epoxy resin contain high dielectric constants. Therefore, this research was conducted in order to develop novel low-dielectric constant Kevlar and glass fiber polymer matrix composites via the wet lay-up and vacuum bagging techniques by utilizing epoxy resins modified with Polyimide (PI) and 2wt.% to 8wt.% of KH-550-modified silica nanoparticles. Dielectric constant tests revealed that the epoxy resin/Kevlar and epoxy resin/glass fiber samples modified with PI/2wt.% to 8wt.% of KH-550-modified silica nanoparticles possessed extremely low dielectric constants below 3 (ideal for commercial aircraft radomes). Conversely, mechanical testing indicated that they contained lower flexural strengths and interlaminar shear strengths while their impact resistances and damage resistances improved. Additionally, fracture toughness tests revealed that the modified epoxy resins contained lower fracture toughness’ when compared to the pure epoxy resin. The novel Kevlar samples also contained higher thermal stabilities at 1000°C while the novel glass fiber samples possessed enhanced glass transition temperatures. Hydrophobicity tests indicated that the epoxy resins modified with PI and 2wt.% to 8wt.% of KH-550-modified silica nanoparticles were hydrophilic in nature. Based on the overall results, it was discovered that the epoxy resin + Kevlar and epoxy resin + glass fiber samples incorporated with PI and 2wt.% of KH-550-modified silica nanoparticles possessed optimal dielectric constants, mechanical properties and thermal properties for potential application in commercial aircraft radomes.

Author

• Rajakaruna, Rajakaruna Athukoralage Dulitha Nuwan Vishma

Identifier

hdl:10057/56121

OAI identifier oai:identifier

oai:soar.wichita.edu:10057/56121