Polymers that function as heat conductors

Scientists from Massachusetts Institute of Technology (MIT) have introduced a new method of producing conductive polymers.

Polymers are materials than are normally used to trap heat while heat conduction is mostly associated with metals. However, for the first time, researchers have managed to produce polymer films (continuous layers of polymers up to 0.2–0.3 mm thick) that act as heat conductors and perform even better than some metals. The study was recently published in the journal Nature Communications.

The findings are of great importance as such polymers can replace common metal conductors in electronic devices such as mobile phones, laptops, computers and in construction industry while being more lightweight, flexible and durable. "Our bigger vision is, these properties of polymers can create new applications and perhaps new industries, and may replace metals as heat exchangers," Gang Chen, senior co-author of the study and the Carl Richard Soderberg Professor of Power Engineering at MIT, stated.

The project comes after the team's successful attempt to produce highly conductive fibers of polyethylene in 2010. Back then, many industrial manufacturers and investors were attracted by the idea but there was a scale issue as the fiber were very thin to be used in common practices. Therefore, researchers had to find a manner to scale up their conductive polymer fibers. "At that time, we said, rather than a single fiber, we can try to make a sheet. It turns out it was a very arduous process," Prof. Chen, stated.

The team managed to produce thin films of conducting polymers beginning with the fabrication of a polyethylene powder. Typically, a polyethylene powder consists of a microscopic structure that includes tangled molecular chains from which heat cannot be transferred easily. This is why polymers are normally insulators. However, the researchers found a technique to untangle those chains increasing the materials' heat conduction by 60-120 times making it even more conductive than steel and ceramics.

In the future, the scientific crew will look into how to optimize the procedure of transforming polymers into heat conductors by investigating on the fabrication technique and on the utilization of different kind of polymers.