Aerospace polymers are shaping up: Structural and functional properties can go hand in hand

A little more than half a century ago wood was the material of choice for building an aircraft. Although readily available and easy to process, this material was rapidly overtaken by aluminum in the early 60’s. More recently Boeing introduced the 787, which is over 50% by weight a polymer-based composite aircraft. Aerospace engineers are always on the lookout for new enabling materials because new materials open routes towards novel airplane and spacecraft designs. Current state-of-the-art aerospace materials include ductile and fatigue resistant aluminum alloys and light-weight carbon-fiber reinforced polymer composites, which combine high strength with high stiffness. The driving force behind these developments: to allow aerospace engineers to design lighter, faster and safer aircraft and spacecraft. For future aircraft and spacecraft designs, however, weight reduction will not only be achieved by replacing structural components by lighter ones but by designing materials which are able to combine structural tasks with systems functionality. Shape memory polymers, for example, are able to provide structural integrity and actuator capability, resulting in a morphing wing or control surface. In addition to morphing structures, one can envision carbon-fiber reinforced composites where the polymer component functions as an organic transistor and provides in-situ health monitoring capability for a light-weight high-speed jetliner. A structural foil for solar propulsion in space can be designed such that it acts as polymer photovoltaic cell and battery. The role of multifunctional polymers in aerospace applications might again prove to be a game changer.

T.J. Dingemans

25-6-2010 13:00:00