Researchers at MIT have made a notable breakthrough in transforming polyethylene, the most widely used polymer, into a material that conducts heat just as well as most metals while retaining its properties as an electrical insulator.
Plastics?? Sounds weird but interesting. Can't wait to find out how it does.

http://www.tomshardware.com/news/mit-cooling-polyethylene-heatsinks-overclocking,9853.html