Aromatic thermosetting copolyester nanocomposite foams: High thermal and mechanical performance lightweight structural materials

In this study, we present carbon nanoparticle incorporated high-performance aromatic thermosetting copolyester (ATSP) nanocomposite foams. The ATSP nanocomposite foams were fabricated through a facile solid-state mixing method wherein carboxylic acid and acetoxy-functional group oligomers were initially combined with chemically pristine carbon nanofillers separately, while in powder form. The mixtures were then subjected to a thermal condensation polymerization reaction in which the constituent oligomers formed the ester backbone of the ATSP matrix and advanced the molecular weight while acetic acid was emitted as the by-product, and generated a porous nanocomposite morphology. As compared to a neat ATSP foam, the nanocomposite foams exhibited a reduced coefficient of thermal expansion by 25% to 75 × 10⁻⁶ °C⁻¹. Thermal stability temperature at 5% mass loss was increased by 30 °C exceeding 500 °C. Compressive mechanical strength was enhanced two-fold, reaching 16 MPa along with a nearly doubled fracture strain, which ultimately yielded improved material toughness.