Maleimido Terminal Triaryl Pyridine Core Skeletal Modified Benzoxazine/Cyanate Ester Co-Cured Polymer (PBZ/CE) Hybrid Blends

Three new types of skeletal modified maleimido terminal benzoxazine monomers (MI-BZs) were structurally designed and synthesized using N-(4-hydroxyphenyl) maleimide and formaldehyde solution through Mannich condensation reaction and were characterized by physico-chemical methods. Thermosetting polymer blends composed of benzoxazine-cyanate ester (PBZ/CE) were successfully prepared via co-curing of benzoxazines with cyanate esters such as biscyanate ester (BCE) and methylene diphenyl dicyanate (MDE). The cured new thermosetting blends from benzoxazine and cyanate ester resin exhibited good thermal stability, improved flame retardancy, low dielectric constant and better water uptake resistance. The shift in the luminescence emission has revealed the clear indication of formation of hybrid network via co-curing of benzoxazine matrices with cyanate ester. This was ascribed to the cycloaddition reaction between the two groups followed by the ring-opening of benzoxazine and cyclotrimerization of cyanate ester. The molecular level dispersion of the cyanate ester onto the benzoxazine matrices was evidenced by SEM analysis.