Reversible covalent crosslinked polyurethane and epoxy resin composite and preparation method thereof

The invention discloses a reversible covalent crosslinked polyurethane and epoxy resin composite comprising two components: linear polyurethane and linear epoxy resin, wherein side chains of the reversible covalent crosslinked polyurethane and epoxy resin composite are respectively provided with a dienophile functional group and a diene functional group; the composite is a material with a crosslinked network structure, which is formed by connecting linear polyurethane and linear epoxy resin through a Diels-Alder reversible covalent bond; the Diels-Alder reversible covalent bond can be reversibly broken and bonded through temperature adjustment, so that the composite conversion between a linear polymer and the material with the crosslinked network structure has the characteristic of reversible covalent crosslinking. The reversible covalent crosslinked polyurethane and epoxy resin composite has the advantages that the mechanical and thermodynamic properties are excellent, and the mechanics can be adjusted within a relatively wide range; the preparation method is simple, convenient and controllable, the reversible covalent crosslinked polyurethane and epoxy resin composite is high in yield, good in quality and wide in application range, and the performance of the composite can be optimized through being re-modified by using filler.