Research On Ultra High Molecular Weight Polyethylene Fiber Reinforced Epoxy Resin-Based Bulletproof Composite Material

Due to its excellent mechanical properties and impact resistance,Ultra High Molecular Weight Polyethylene Fiber(UHMWPE)is widely used in the field of bulletproof composite materials.However,its surface lacks polar groups,so there is no suitable resin matrix to compound with it.And its heat resistance is very low,so it is necessary to select appropriate resin matrix with high temperature resistance and strong toughness when using it.In this paper,solvent-free modification of epoxy resin was carried out,and curing process of epoxy resin,interfacial bonding property between matrix resin and fiber,and the bulletproof performance of composite material were studied,and the following conclusions were drawn:In this paper,14 polyethersulfone epoxy resin,including two polymers and twelve oligomers,were synthesized by copolymerization of eight kinds of diphenyl phenols and bis(4-chlorophenyl)sulfone and performed end-capping of polymerization.Their structures were determined by infrared characterization,and the results showed that end-capping cannot be performed on the polymer,while the end-capping of the oligomer can be successful.The four long-and short-chain formulations(BPASE32,BPASE21,RESE2 and RESE21)synthesized from bisphenol A and resorcin and the two shortchain formulations(HQSE21 and THQSE21)synthesized from hydroquinone and omethylhydroquinone both can be solvent-free and miscible with epoxy resin,the maximum miscibility ratio is 60%.Among them,the four formulations synthesized from bisphenol A and resorcin have the best comprehensive thermal performance,with a glass transition temperature of 171 to 186°C and a thermal decomposition temperature of 453°C to 484°C.BPASE32 solvent-free and miscible epoxy matrix resin was prepared with different curing agents,the results show that: The epoxy matrix resin mixed with anhydride curing agent(MTHPA,MNA)and a small amount of polyether amine(CAD-2000)has the best comprehensive.Its apparent activation energy is 62.3?66.6 KJ/mol,relative permittivity is between 4.22?4.56,water absorption is about 0.7%,indicating that gelation time is short,reaction activity is high,and it can adapt to humid environment.The tensile shear strength at200? is more than 16 MPa,which is nearly 15% higher than that of pure anhydride curing agent,and can fully meet the resin based strength and heat resistance of bulletproof composites.Among them,the epoxy matrix resin system prepared by MTHPA has the lowest viscosity,which is conducive to coating at room temperature.By mixing different polyethersulfone epoxy resin and MTHPA/CAD-2000,different epoxy matrix resins were prepared,among which,the addition of bisphenol A and resorcin polyethersulfone epoxy resin(BPASE32,BPASE21,RESE21)made the epoxy matrix resin with the best comprehensive properties.Its viscosity is low at room temperature and 50 m Pa·s above 70?.It can be fully infiltrated with UHMWPE.The apparent activation energy is 64KJ/mol,the reaction water absorption is within 0.8%,and the dielectric constant is between 3.9and 4.6.The tensile shear strength is more than 16 MPa at room temperature,the tensile shear strength is increased by 15% at 200?,and the elongation at break is 13-17%.Compared with the formulation without polyethersulfone epoxy resin,the tensile shear strength is increased by33% at room temperature and 110% at 200?.The interfacial bond strength of epoxy matrix resin modified by polyethersulfone epoxy resin reaches 1.20?1.29 MPa.The tensile strength and elongation at break of UHMWPE/ epoxy resin based composite filament after curing at 90? for 60 min were the highest,reaching 40 c N/dtex and 4.7%,respectively.UHMWPE/epoxy resin based unidirectional board has the best tensile strength when the fiber volume fraction is 85%,which is 1413 MPa.The composite material was prepared by 0°/90°UD structure,and was fired with 7.62 mm bullet at a velocity of 435 m/s.The composite material was not punctured,the height of the convex back was 25 mm,and the absorption energy of the target plate was 529.83 J,which met the requirements of the convex back of bulletproof composite material.