Benzoxazine Resin Monomer Containing Nitrile Class Composites

The attractive characteristics of benzoxazine polymers include low melt viscosity, no release of volatiles during cure, no need for harsh catalysts, high thermal stability, good mechanical properties, excellent electrical properties and molecular design flexibility. By taking advantage of the molecular design flexibility of benzoxazine, we choose different hydroxybenzene or amine to synthesis different benzoxazine in order to improve the properties.In this paper, we synthesis two types of benzoxazine monomers containing cyano function, which can be crosslinked by heat and catalyst, and improved the nitrogen percentage of the polybenoxazine and heat-resistance.The diamine containing CN group, 2, 6-bis (4-diaminobenoxy) was synthesized by 4-aminophenol and 2, 6-dicholobenzonitrile in the polarity non-protonic solvent. The benzoxazine monomer containing CN group was synthesized by the diamine, phenol and formaldehyde in solution. The structure of the monomer is supported by FTIR,¹H-NMR,¹³C-NMR. At the same time, the curing behavior was researched by FTIR,DSC and rheometer. The thermal and thermo-oxidative stabilities of the benzoxzine were investigated by thermogravimetric analysis (TGA).The amine, 4-aminophenoxylphthalonitrile, was synthesis by 4-aminophenol, 4-nitrophthlonitrile and potassium carbonate.The novel bisphthalonitrile containing benzoxazine (BPNBZ) has been synthesized using bisphenol-A, 4-aminophenoxylphthalonitrile and paraformaldehyde. The structure of the monomer is supported by FTIR,¹H-NMR,¹³C-NMR. The curing behavior, the structures of the prepolymers and polymer, the Tg, the thermal and thermo-oxidative stabilities and the rheological behaviors were researched by FTIR DSC TG rheometer.The preparation and the properties of the BPNBZ/glass fiber/ multi-walled carbon nanotube (MWNTs) composites were investigated in this paper, useing the method of solution blend to disperse MWNTs in the matrix resin. We realized the dispersion of the MWNTs through scanning electron microscope (SEM) scan the fractured surface.Then we test the content of MWNTs on the mechanical properties, electrical properties, and chemical resistance, the thermal and thermo-oxidative stabilities of the glass fiber-resinforced resin composite materials.