The rapid advancement of aerospace and wind power industries necessitates epoxy resin matrices with simultaneous high strength and high toughness. However, conventional modification methods struggle to mitigate the trade-off between strength and toughness in epoxy resins, rendering the development of epoxy resins with both high strength and high toughness a persistent challenge. In this study, two Xylok epoxy resins (X-PPEP and X-BPEP) were synthesized utilizing para-xylene dimethyl ester (PXDM) and 4,4′-bis(methoxymethyl)biphenyl (BMMB) as raw materials, respectively. Subsequently, with 4,4′-diaminodiphenylmethane (DDM) serving as the curing agent, the properties of the corresponding castings and composites were investigated. The results reveal that the crosslinked networks of X-PPEP/DDM and X-BPEP/DDM exhibit highly rigid backbones and substantial free volume fraction, thereby endowing them with exceptional mechanical properties. Specifically, the tensile strength and elongation at break of both systems exceeded 90 MPa and 7%. The impact strength of X-BPEP/DDM reached 49.72 kJ/m2. Furthermore, the glass fiber-reinforced composites based on these resins also exhibited excellent mechanical properties. These findings provide a viable strategy for fabricating epoxy resins with balanced strength and toughness, highlighting the significant application potential of X-PPEP and X-BPEP in high-performance sectors such as aerospace and wind power generation.
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