Materials used for military personal protection gear may also be tough enough for vehicles, potentially improving how unmanned vehicles dissipate energy. Researchers are studying the use of the polymers as matrix material for incorporation into lightweight composites in unmanned vehicle systems.
Polyurethanes are versatile materials used in a broad variety of applications including coatings, foams, and solid elastomers. As film adhesives, for example, they are commonly used as bonding agents between layers of glass and as polymer back layers in transparent glass or plastic composites such as vision blocks on side windows in tactical vehicles. In particular, high-performance segmented PUU polymers exhibit versatile physical and mechanical properties.
Hierarchical composites are a promising area of research for Army vehicles as they are less susceptible to corrosion, leading to early component death. In contrast to traditional thermoset composites, performance poly(urethane-urea) elastomers are far less brittle and offer better control over material architecture. Carbon nanotube/polymer composites have desirable electrical and thermal characteristics that exhibit behaviors superior to conventional fiber materials.
Chemical modification of nanofillers is nontrivial and typically diminishes their properties by changing their structure and chemistry; for example, the Young modulus could be lower. The team’s results strongly indicate the effectiveness of incorporation of aligned carbon nanotubes for microstructure optimization of hierarchical PUU polymers in the matrix as well as at the interface without any filler surface modification.
Future Army vehicles could see an improvement in their structural materials since they are less susceptible to corrosion, lightweight, and have higher electrical conductivity than traditional elastomers. The materials also show great potential to protect vehicles against static buildup and discharge, and lightning strikes.
Military vehicles such as Army helicopters must withstand intense vibration and fatigue and the conductive nature of these materials could lead to a greater level of multifunctionality. The materials also could provide real-time structural health monitoring through embedded strain sensing and damage monitoring for safe and accurate assessment of the remaining life in vehicle components.