Microstructure Analysis Based on Gas Isotherms of N2, H2O and CO2 and 3D Imaging Using X-Ray CT into Extruded Polystyrene foam Adding Graphite

A type of foamed plastic insulation that improves thermal performance while maintaining the original durability by adding fillers with low radiation rates in foamed plastic insulation is investigated. The thermal conductivity of extruded polystyrene foam (XPS) adding graphite is reduced by 14% compared to without graphite additives. The study investigates that mechanism by comparing the properties of XPS and XPS containing graphite (graph XPS) through the gas isotherm method and 3D imaging analysis by X-ray CT. First, the specific surface area of the insulation's resin is examined through the gas isotherm method using N2, H₂O, and CO₂. The results confirmed that graph XPS has a more increased specific surface area than XPS. Second, the internal structure of the insulation and its strut/pore distribution is confirmed through X-ray CT, which showed an increase in surface area with a thinning of the strut. The improved thermal performance due to the addition of graphite may contribute to an increase in the surface area of the insulation.