Toughening of epoxy resins with tetramethylbiphenyl containing soluble polyaryletherketone

The inherent brittleness of epoxy (EP) has long imposed limitations on its utilization within advanced field. This study synthesized a novel high-performance soluble polymer with a tetramethyl biphenyl structure (named tetramethyl biphenyl poly arylene ether ketone, S-TBPAEK) as a toughening agent for preparing EP composites. The aromatic structure in S-TBPAEK enhanced the heat resistance of composites, while its unique tetramethyl structure promoted excellent compatibility with EP. Additionally, it was observed that when S-TBPAEK content reached 12.5 phr, the impact strength of composite was significantly increased by 170 %. Additionally, the mechanical properties of the composite, such as flexural strength and tensile strength, have been enhanced by approximately 43.7 % and 55.8 % respectively. Finally, the fracture surfaces of the composites were analyzed using SEM to investigate the fracture mechanism. The results revealed that the fracture behavior of impact, flexural and tensile specimens transitioned from brittle to ductile fracture. The phenomenon suggested that the S-TBPAEK/EP composite absorbed more energy during fracturing process, thereby enhancing its toughness. In summary, S-TBPAEK shows great promise as a toughening agent for epoxy composites, offering new insights into the field of epoxy toughening.