Tri-functional phthalonitrile monomer as stiffness increasing additive for easy processable high performance resins

A new tri-functional phthalonitrile monomer tris(3-(3,4-dicyanophenoxy)phenyl) phosphate (TPP) was first synthesized and characterized with the intent of increasing the cross-linking rate of phthalonitrile resins. By combining TTP and di-functional phthalonitrile with aromatic diamine easy-processable formulations (eta < 200 mPa.s at 150 degrees C) were developed. Thermosets were derived from the formulations by curing at 330 and 375 degrees C. The polymers that were post-cured at 375 degrees C demonstrated Young's moduli up to 7.2 - GPa which is the highest value reported for phthalonitriles. Thermal stability of these materials was on the high level featured to phthalonitriles (T-g > 450 degrees C, T-5% > 500 degrees C, TOS5% > 500 degrees C, Yc at 900 degrees C > 80%). TPP, the introduced monomer, can be used as a stiffness increasing additive with common di-functional phthalonitriles, and easyprocessable formulations for cost-effective techniques of composites manufacturing.