▎ 摘　　要

NOVELTY - Graphene-based sheet comprises 75-99 wt.% graphene nanoplatelets and 1-25 wt.%, preferably no more than 20 wt.% polymeric matrix. USE - The graphene-based sheet is useful for incrementing the protection to fire, mechanical damping and/or thermal dissipation of composite material and/or for shielding against electromagnetic waves (all claimed). ADVANTAGE - The graphene-based sheet has: a surface electric resistance greater than or equal to 1x 10-4 Ohm/square (claimed); high protection under fire conditions by means of flame ignition delay, decreases in flow of toxic volatiles, and in case self-extinction, an improves electric and thermal conductivity and mechanical damping of the structure/component or of the material, especially for composites with polymeric matrix and polymers. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are also included for: (1) preparing graphene-based sheets comprising (a1) mixing graphene nanoplatelets with polymeric matrix, where weight ratio the graphene nanoplatelets and the polymeric matrix is 75:25- 99:1 and the nanoplatelets comprises carbon content of greater than 98%, thickness of 5-30 nm, average surface sizes of 1-200 mu , bulk density of 0.01-0.05 g/cm3, (a2) depositing by means of spraying or squeegee or roller spreading the mixture obtained, (a3) pressing by means of lamination or press the material deposited with the step (a2) and (a4) optionally repeating at least one time previous steps to obtain sheet with the wished grammage; and (2) composite material, preferably in carbon fibers with epoxy resin, where on its inner or outer surface the graphene-based sheet is applied.