Investigation of Properties of Polyimide-Grafted Erythritol Composites Filled with Oxidized Expanded Graphite by In Situ Fabrication for Advanced Phase Change Materials

Abstract

Owing to their high latent heat enabling thermal energy conservation upon heat absorption and release, phase change materials (PCMs) are attracting increasing interest for use in thermal energy storage systems and next-generation thermal management systems. However, they have limitations such as inherently poor thermal and mechanical properties, which hinder their practical use. To overcome these limitations, we prepared a novel PCM based on polyimide- (PI-) grafted erythritol (PIET) through in situ grafting and imidization using PI. PIET composites that were prepared using oxidized expanded graphite as a filler showed an improved thermal conductivity of 2.56 W·m-1·K-1 in the through-plane direction, a latent heat of 192.5 J·g-1, and a tensile strength enhanced by 119%. Thus, the prepared PCM composites showed the potential for the development of advanced PCMs.