Improvement of the mechanical and thermal properties of polyethersulfone-modified epoxy composites

The uniform dispersion of PES in epoxy resin and the formation of semi-interpenetrating polymer networks (semi-INP) from reaction of PES particle and epoxy resin influenced on improvement of mechanical properties. •The PES of various contents as additive was embedded into triglycidyl-p-aminophenol (TGAP) epoxy resin that has outstanding properties.•The maximum mechanical strength of PES/epoxy composites was observed in improvement by 44%.•The thermal stability of the PES/epoxy composites improved by 17%.•The formation of the semi-interpenetrating polymer networks (semi-IPNs) composed of the epoxy network and linear PES improves PES/epoxy composites properties. We evaluated the use of polyethersulfone (PES) as reinforcement material to increase the mechanical and thermal properties of triglycidyl-p-aminophenol (TGAP) epoxy resin. The enhancement of the mechanical properties of the PES/epoxy composites was indicated by 44%, 35%, and 11% increases in tensile strength, impact strength, and fracture toughness, respectively. TGA revealed that the thermal stability of the PES/epoxy composites also improved by 17%, which was calculated using the integral procedural decomposition temperature (IPDT). These results are attributed to the good distribution and formation of the semi-interpenetrating polymer networks (semi-IPNs) that composed the epoxy network and the linear PES.