Abstract
Poly (ether ketone ketone) s were prepared and used to improve the brittleness of the cyanate ester resin The poly (ether ketone ketone) s include poly (phthaloyl diphenyl ether) (PPDE), poly (phthaloyl diphenyl ether-co-isophthaloyl diphenyl ether) (PPIDE) and poly (phthaloyl diphenyl ether-co-terephthaloyl diphenyl ether) (PPTDE). PPDE was more effective as a modifiers for improving the brittleness of the cyanate ester resin than were PPIDE (50 mol% isophthaloyl unit) and PPTDE (50 mol% terephthaloyl unit). When using 15 wt% of PPDE (MW 28,300), the modified resin had a particulate structure and the fracture toughness (KIC) increased 30% at a slight loss of flexural strength and no deterioration of flexural modulus and glass transition temperature, compared with those of the unmodified cured cyanate ester resin. The thermal stability of the modified resin was also comparable to that of the unmodified resin. Water absorptivity of the cured resin was not deteriorated by the modification with PPDE.
