▎ 摘　　要

NOVELTY - Preparing polyimide-based co-carbonized carbon fiber complex material with high thermal conductivity and electromagnetic shielding, comprises (i) preparing modified polyimide fiber felt by using pyromellitic dianhydride as dianhydride monomer, and diamine monomer selects diamine monomers containing benzene rings, obtaining polyimide fiber mats through thermal imidization, (ii) functionalization and co-carbonization of modified polyimide felt by making prepared polyimide felt, impregnating polyimide felt in two-dimensional layered nanomaterial dispersions including graphene, graphene oxide, Mxene, molybdenum disulfide, etc. by roll-to-roll process, and drying and rolling, co-carbonizing modified polyimide needle felt, co-carbonizing or graphitizing polyimide fibers or with two-dimensional layered nanofillers, and (iii) preparing high-performance resin-based carbon fiber composite material, immersing three-dimensional co-carbonized carbon fiber reinforcement in high-performance resin. USE - The method is useful for preparing high thermal conductivity electromagnetic shielding polyimide co-carbonized carbon fiber complex material, which is useful in military, aviation, aerospace, machinery and energy fields. ADVANTAGE - The co-carbonization process can improve the conductivity of the skeleton, and the co-carbonization between the two-dimensional nanofiller and the carbon fiber produces a heterogeneous structure, which can greatly improve the electromagnetic shielding performance of the material; The three-dimensional co-carbonized carbon fiber reinforcement is impregnated with high-performance resin, the three-dimensional reinforcement structure is well maintained in the composite material. The composite material has good mechanical properties, we have prepared a three-dimensional high-performance resin-based co-carbonized carbon fiber composite material that can simultaneously take into account excellent thermal conductivity, ultra-high electromagnetic shielding and mechanical properties. DETAILED DESCRIPTION - Preparing polyimide-based co-carbonized carbon fiber complex material with high thermal conductivity and electromagnetic shielding, comprises (i) preparing modified polyimide fiber felt by using pyromellitic dianhydride as the dianhydride monomer, and the diamine monomer selects diamine monomers containing benzene rings such as p-phenylenediamine and biphenylenediamine to prepare polyamic acid PAA, adding 0.1-3 wt.% graphene, graphene oxide, Mxene, molybdenum disulfide and other two-dimensional layered nanomaterials into PAA to disperse evenly to obtain a modified PAA solution, and prepare a modified polyamide Acid spinning solution precursor, the solid content of modified PAA in the spinning solution is 20%, preparing randomly or orderedly arranged modified polyamic acid spinning fiber mats by electrospinning, and then obtain polyimide fiber mats through thermal imidization, (ii) functionalization and co-carbonization of modified polyimide felt by making prepared polyimide felt into a three-dimensional polyimide needle felt by a three-dimensional needle punching process, impregnating polyimide felt in two-dimensional layered nanomaterial dispersions including graphene, graphene oxide, Mxene, molybdenum disulfide, etc. by a roll-to-roll process, and then drying and rolling, co-carbonizing the modified polyimide needle felt at high temperature or graphitized at a higher temperature, co-carbonizing or graphitizing polyimide fibers or with two-dimensional layered nanofillers to obtain a perfect and connected structure three-dimensional co-carbonization network structure, (iii) preparation of high-performance resin-based carbon fiber complex material, immersing three-dimensional co-carbonized carbon fiber reinforcement in a high-performance resin, so that the three-dimensional co-carbonized carbon fiber reinforcement is composited with the high-performance resin, and a super high-performance resin with excellent thermal conductivity is prepared high-performance resin-based carbon fiber complex material with electromagnetic shielding and good mechanical properties. Due to the formation of polyimide-based carbon fibers after carbonization of polyimide and the co-carbonization of functional fillers, the three-dimensional co-carbonized network structure has good three-dimensional connectivity, which reduces the interfacial thermal resistance between fillers and makes it have excellent thermal conductivity. An INDEPENDENT CLAIM is included for high thermal conductivity electromagnetic shielding polyimide-based co-carbonized carbon fiber complex material has a three-dimensional co-carbonized network structure, which is formed while polyimide-based carbon fibers are formed during the co-carbonized process, form a heterogeneous structure with two-dimensional nanomaterials, and jointly build a well-formed, a connected three-dimensional co-carbonized network structure, the network structure makes the complex material have excellent thermal conductivity, as well as excellent electrical conductivity and ultra-high electromagnetic shielding performance.