The phosphorus-containing poly(arylene ether ketone) (P-PAEK) with the advantage of insolubility in BMI resin at the injection temperature was chosen as the toughener of RTM resin.The U3160 carbon fiber reinforced BMI resin composites interlaminar toughened by P-PAEK particles was fabricated via RTM process.Through research on the influence of P-PAEK particles with different contents on the impact strength properties of BMI resin

it was found that the toughness of matrix resin could be greatly improved by adding a few thermoplastic resin particles.The impact strength was increased from 10.3 kJ/m2 to 30.3 kJ/m2.The microscopic morphology was observed by SEM and toughening mechanism was analyzed.When the content of P-PAEK increased

the microstructure of TP/TS system experienced sea-island

co-continuous and phase inversion transition.The sea-island structure could absorb more energy than the other one

which attributed to the toughening mechanism of rigid particles.The interlaminar fracture properties of the composite were characterized by Mode Ⅰ and Mode Ⅱ fracture toughness tests.It was found that the GⅠC and GⅡC of toughened U3160/BMI composites were well improved when the areal density of P-PAEK particles was 2 g/m2.It was improved 56% of GⅠC and 42% of GⅡC compared to the U3160/BMI composites.The mechanical properties of composites were well kept

as the CAI increased by 29% and interlaminar shear strength was 111.7 MPa.