Recent developments in RAM based MWCNT composite materials: a short review

The need to develop radar absorbing materials (RAMs) that meet the structural requirement of defense applications is growing swiftly, due to the extensive use of electromagnetic waves in Radar. With the major developments and extensive use of Radar in military applications, the role of Radar absorbing, light weight and high strength structures has become a prime objective for researcher working on the development of RAMs. Various composites have been developed by using reinforcements which are dielectric, such as carbon nanotubes (CNT), magnetic materials like ferrites, that have been extensively used for reinforcement when developing RAMs. Ferromagnetic materials have a high density and can only achieve a narrow bandwidth of absorption. CNT have very good electrical, mechanical and thermal properties and can achieve high dielectric losses but their complex synthesis process is a barrier to commercial applications. Research on reinforcing multi-walled carbon nanotubes (MWCNT) with ferrites and metal oxides can also be extended to the study of thermoplastic polymers like polyether ether ketone and polyaryletherketone, which are gaining prominence in aeronautical applications, owing to their superior mechanical and low moisture absorbing properties. Further research can be carried out on reinforcing metal oxides, as metal oxides, when reinforced with MWCNT enhance the dielectric properties which improve the reflection losses as reported in a few studies.