Researchers at the University of Michigan in Ann Arbor have developed plastic that is 10 times better at conducting heat than conventional counterparts and may lead to making more powerful electronics or more efficient vehicles, say the authors of the study, published in the current issue of Nature Materials.
“We improved those connections so the heat energy can find continuous pathways through the material,” says Jinsang Kim, associate professor of materials science and engineering at U-M, who led the project with colleague Kevin Pipe. “There's still a long way to go, but this is a very important step we made to understand how to engineer plastics in this way. Ten times better is still a lot lower heat conductivity than metals, but we've opened the door to continue improving.”
The new material, which is actually a blend, results from one of the first attempts to engineer the flow of heat in an amorphous polymer, or a large molecule made of smaller repeating molecules.
Kim says previous efforts to boost heat transfer in polymers have relied on metal or ceramic filler materials, or stretching molecule chains into straight lines. “Those approaches can be difficult to scale up and can increase a material's weight and cost, make it more opaque, and affect how it conducts electricity and reflects light,” he says.
The U-M material has none of those drawbacks, and it's easy to manufacture with conventional methods, according to Kim and Pipe.
“Researchers have paid a lot of attention to designing polymers that conduct electricity well for organic LEDs and solar cells, but engineering of thermal properties by molecular design has been largely neglected, even though there are many current and future polymer applications for which heat transfer is important," Pipe says.
The research was funded by the U.S. Department of Energy, Office of Basic Energy Sciences as part of the Center for Solar and Thermal Energy Conversion in Complex Materials, an Energy Frontier Research Center.