Living cells and natural polymers hold the clues to crafting a better man-made plastic – one that can endure extremes in temperatures and chemical introductions to retain its form and function. This key, says Christopher Ober, is the process through which different proteins or polymers stick together.
"Most polymers' formation is random, yet enzymes and natural polymers beat the system – they're non-random," said Ober, professor of materials science and engineering at Cornell University.
To get around this randomness, Ober, his colleagues, and his students studied self-organizing polymers, materials such as liquid crystalline and block copolymers that spontaneously form large-scale patterns – in much the same way that amino acids gather to form long chains of proteins. What allows these large-scale patterns to form is the way in which the polymers bond, a single molecular interaction.
Choosing the correct molecule to bind together different polymers is essential, as distinct plastics mix together about as well as oil and water, Ober said. For his work, Ober is using a single carbon-carbon bond. The combination of polymers like liquid crystalline and block copolymers along with the carbon result in a super plastic that can withstand very harsh environments such as extreme heat and cold – as well as Atlantis-like surroundings.
The Office of Naval Research, which is among the organizations funding Ober's work, is counting on these plastics for new non-stick coatings that are so slick that barnacles and other marine life won't be able to attach themselves to ships and submarines.
Ober said science has the hang of simple plastics – the Hefty bag is a well-worn concept, after all. But compound plastics will be asked to do more – even replace metals, as is the case with a Department of Energy satellite called FORTE that was launched last week. It is the first such craft with a frame made entirely of plastic – a graphite-epoxy compound that doesn't warp in the extreme heat and cold of space.
