A study on sisal fiber-reinforced benzoxazine/epoxy copolymer based on diamine-based benzoxazine

A diamine-based benzoxazine monomer has been synthesized via the Mannich condensation reaction of ethylenediamine, phenol and formaldehyde. The effect of solvent was investigated. The chemical structure and thermal properties of the diamine-based benzoxazine were characterized by FT-IR, NMR, DSC and TGA. Sisal fibers are incorporated in a mixture of benzoxazine and bisphenol-A type epoxy resins to form a unidirectionally reinforced composite. The effects of varying fiber contents and matrix composition on the mechanical properties of the composites are studied.