Easy processable tris-phthalonitrile based resins and carbon fabric reinforced composites fabricated by vacuum infusion

Easy-pmcessable phthalonitrile resins were prepared from tris-phthalonitrile phosphate monomer TPP (tris(3-(3,4-dicyanophenoxy)phenyl)phosphate), bis-phthalonitrile RP (bis (3,4-dicyanophenoxy)benzene) and novel viscosity reducing comonomer CPN (4-(4-cyanophenoxy)benzene-1,2-dicarbonitrile). It was shown that TPP is more resistant to hydrolysis than reported phosphate based phthalonitriles (k =8.2.10(-4) s(-1) at 65 degrees C and pH 10). Two different type of curing agents: aromatic diamine DDS and 4-(4-aminophenoxy) phthalonitrile APN were used to study their effect on properties of the obtained resins and composites. Carbon fabric composites with APN-cured matrix fabricated by vacuum infusion demonstrated compression strength up to 633 MPa and 100% retention of ILSS after oxidative aging for 200 h at 300 degrees C. Post-curing of the matrix at 375 degrees C resulted in growth of Tg but at the same time micmcracking occurrence in the composite leading to decrease in mechanical properties and thermal aging sustainability.

Automated summary

Easy-processable phthalonitrile resins were prepared using novel viscosity reducing comonomer CPN. Different curing agents, aromatic diamine DDS and 4-(4-aminophenoxy) phthalonitrile APN, were used to study their effects on material properties. Carbon fabric composites with APN-cured matrix showed high compression strength and thermal aging sustainability, but post-curing at 375 degrees C resulted in decreased mechanical properties.