A new cyano-based resin with high curing reactivity and unexpectedly lower melting point: Pyrazine-2,3-dicarbonitrile resin

Abstract

The processing difficulties of aromatic cyano-based resins have always been a challenging issue in this field. Currently, a new approach to solving this problem is the modification of the chemical environment of the cyano group. In this work, a bifunctional pyrazine-2,3-dicarbonitrile resin 5,5'-((propane-2,2-diyl)bis(4,1-phenylene))bis(oxy))bis(pyrazine-2,3-dicarbonitrile) (BPQCN) was successfully synthesized and compared to the control resin 4,4'-((propane-2,2-diyl)bis(4,1-phenylene))bis(oxy))bis(phthalonitrile) (BPAh). Thermal analysis and spectroscopic analysis together demonstrate that the pyrazine moiety endow the resin with higher cross-linking reactivity and a lower melting point. Meanwhile, spectroscopic analysis results show that the major cured products of the BPQCN are azaisoindoline and azaphthalocyanine. In addition, thermal gravimetric analysis (TGA) and dynamic mechanical analysis (DMA) show that the cured resin has the typical characteristics of high-performance thermosetting resins, with excellent thermal stability and heat resistance. The successful preparation of pyrazine-2,3-dicarbonitrile resin is promising to bring new members to the family of aromatic cyano-based resins.