Toughening effect of self-assembled thermoplastic particles on phthalonitrile containing benzoxazine and improved mechanical properties in the presence of fibers reinforcement

Phthalonitrile containing benzoxazine resin (BA-ph) was a new type of high-performance resin which could be used at high temperature by autocatalytic molding at low temperature. However, its brittleness after polymer-ization and weak interaction with fibers when it as the matrix of fiber reinforced composites (FRC) were ob-stacles to its wide application. In this study, Poly (arylene ether nitrile) containing phenolphthalein (PP-PEN) was introduced by solution blending to toughen BA-ph and its glass fiber (GF) FRC. The effects of PP-PEN on the crosslinking behavior and processability of BA-ph were studied by differential scanning calorimetry (DSC) and dynamic rheology analysis (DRA). The effect of PP-PEN on the structural strength and thermal stability of BA-ph/ GF was further studied by other characterization methods. The non-notchable impact strength of BA-ph/PP-PEN/ GF FRC formed at lower temperature (200 degrees C) could reach 148 kJ/m2, which was 91.4% higher than that of BA-ph/GF FRC. Furthermore, the fracture morphology showed that PP-PEN significantly enhanced the interfacial strength between BA-ph and GF. It has potential applications in aerospace, rail transportation and the fields requiring high-performance polymer matrix FRC.

Automated summary

Poly (arylene ether nitrile) containing phenolphthalein (PP-PEN) was introduced to enhance the toughness of phthalonitrile containing benzoxazine resin (BA-ph) and its glass fiber (GF) fiber reinforced composites (FRC). PP-PEN significantly enhanced the interfacial strength between BA-ph and GF, making it potentially applicable in high-performance polymer matrix FRC.