Preparation method of high-strength fireproof wood-plastic window body material

The invention discloses a preparation method of a high-strength fireproof wood-plastic window body material, and relates to the field of preparation methods of fireproof wood-plastic window body materials. The technical problem to be solved is that an existing wood-plastic window frame material is poor in flame retardant capacity, and a general thermoplastic plastic matrix is low in mechanical property. The method comprises the following steps: preparing and synthesizing phosphorus-containing diamine; reacting dianhydride with phosphorus-containing diamine to obtain phosphorus-modified polyamide acid liquid; dispersing octa-aminophenyl POSS into phosphorus modified polyamide acid liquid, and carrying out thermal imidization treatment to obtain POSS-based phosphorus-containing polyimide; adding thermoplastic plastic, melting and mixing to form a plastic alloy; and extrusion molding. The novel engineering plastic-based wood-plastic composite material with high mechanical property and high flame retardance is ob