Polyethylene (PE) is the most commonly used polymer because it is easy to manufacture and offers many options. Due to its low weight, its good electrical insulation properties and its excellent chemical resistance, there are thousands of applications, especially in packaging, foils, bottles and many more.
The plot above shows the LFA measurement of the thermal diffusivity of a 1 mm thick PE sample. For the measurement the sample was put into a liquid sample holder with a closed bottom and lid. To improve the heat transfer between sample and sample holder, both sides of the sample were coated in the middle with a very thin layer of zirconia coating paste. By that the sample can directly absorb the energy without great loss. The measurement was then performed under helium atmosphere up to 300 °C.
Up to the melting point (between 130 °C and 145 °C) the thermal diffusivity decreases. After the sample melted, the diffusivity slightly increases and starting from 200 °C the sample starts to decompose which can be seen in the decreasing thermal diffusivity.
