▎ 摘　　要

NOVELTY - A poly-4-methylpentene nanosheet composite film is prepared by using 40-55 pts. wt. poly-4-methyl-1-pentene, 10-15 pts. wt. amino-terminated hyperbranched polybenzimidazole, 3-6 pts. wt. surface-modified graphene nanosheet/ceramic nanosheet composite, 1-3 pts. wt. allyl glycidyl ether, and 0.5-1.5 pts. wt. N-(4-cyano-3-(trifluoromethyl)phenyl)methylepoxyacrylamide. USE - Poly-4-methylpentene nanosheet composite film. ADVANTAGE - The poly-4-methylpentene nanosheet composite film has low dielectric loss, large dielectric constant, excellent thermal stability, high breakdown field strength and excellent flexibility, and is easy to process. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for preparation of the poly-4-methylpentene nanosheet composite film, which involves mixing the raw materials, obtaining mixture, adding the mixture to high boiling point solvent, stirring, pouring into mold, placing the mold in a blast drying oven at 85-95 degrees C to dry, placing under normal temperature and inert gas atmosphere, and performing radiation grafting and crosslinking by electron beam radiation equipment.