Thermally Conductive Plastic Films Could Replace Metals in the Near Future

Plastics have always been the go-to choice when it comes to thermal insulation. For example, polymers like silicone and Styrofoam are good at trapping heat. However, the image of plastics as insulators has evolved. Researchers from the Massachusetts Institute of Technology (MIT) have created thin plastic films that have the ability to conduct heat. Compared to plastic wraps,  these films are thinner and conduct heat better than ceramics or metals.

The team is well on its way to create flexible, lightweight, and corrosion-resistant plastic insulators which could in the future replace traditional heat conductors. We could find applications that range from:

• Heat-dissipating elements in laptops and phones
• Cooling material for refrigerators
• Cooling for auotmobiles
• Heat-dissipating fabrics and textiles

According to one of the researchers, Gang Chen, thermally conductive plastic films could have the power to design innovative applications. This could enable many industries to replace alloys and metals as a medium of heat exchangers.

These plastic films were created using polyethylene’s molecular knots. These knots helped the researchers to parallel chains that conduct heat. A custom-built flow system was then built to untangle the chain of the molecules. A liquid-nitrogen-cooled plate was then used to create thick plastic films. These films were later heated and stretched to create ultra-thin plastic wraps.

The team then proceeded to design an apparatus that could measure the film’s heat conduction. Most plastics can usually conduct heat at 0.1-0.5 W/m⋅K. The thin polyethylene films ended up measuring at a whopping 60 W/m⋅K. Moreover, the new films were conductive than steel or ceramic.

The films were later imaged and the team noticed that the material displayed properties that were similar to nanofibres. This discovery could help the team to create microstructures that effectively conducted heat. It should not come as a surprise if we start seeing these thermal plastic films being used in heat conductors in automobiles, innovative electronic devices, and lightweight printed circuit boards for batteries.

Source:

https://news.mit.edu/2019/metal-like-polymer-films-conduct-heat-0430