Research On Preparation And Performance Of Polyethylene/Aramid/Nano Hybrid Composites

Fibre-reinforced thermoplastic resin composites are widely used in aerospace,transportation and personal protection due to their high impact resistance,high designability and recyclability.But there was still room for improvement in the structure design of Low-velocity impact resistance.This paper was based on the design principles for the integration of structure and properties of composites.Kevlar fibers with high strength and high modulus and UHMWPE fibers with low density and high toughness were used as reinforcements.The thermoplastic resin EVA was used as the matrix and nanomaterials were used as the modifying materials.UHMWPE fibers/kevlar fibers hybrid composites with various laminated structures were prepared by hot pressing process.Through bending test,interlaminar shear test,low-velocity impact test,digital camera and scanning electron microscope observation,the influence of hybrid structure and nanomaterials modification on the mechanical properties and low-velocity impact properties of composite materials was analyzed.The low-velocity impact damage mode of composites was investigated.The results showed that the interlayer hybrid structure can effectively improve the mechanical properties of fiber-reinforced resin composites.Compared with single UHMWPE fiber-reinforced and single kevlar fiber-reinforced resin composites,the flexural strength of UHMWPE fibers/kevlar fibers interlayer hybrid structure composites were improved by 36% and 100%,respectively.It also showed more energy absorption and less impact damage at low-velocity impact,showing the "positive hybrid effect".The front and back hybrid structure had the highest mechanical properties in all ply structure designs,with a bending strength of 36.30 MPa and an interlaminar shear strength of 1.07 MPa.Nanomaterials modification was beneficial to improve the mechanical properties and low-velocity impact properties of fiber-reinforced resin composites.Among several nanomaterials,boron carbide nanoparticles had the best reinforcement effect on the composites.The highest mechanical properties and low-velocity impact properties were obtained with the addition of boron carbide nanoparticles at 5%,with bending strength of 42.43 MPa,interlaminar shear strength of 1.18 MPa,low-velocity impact load of 2653.35 N,and impact deflection of 17.55 mm.The impact response of fibers/nanoparticles/resin hybrid composites were manifested in the following aspects.High strength and high modulus kevlar fibers absorbed energy in tension and shear.Low density and high toughness UHMWPE fiber compression deformation and interlayer delamination absorbed energy.Thermoplastic resin EVA matrix cracking absorbed energy.Nanoparticles toughening improved fiber-resin interface,resisted microcracking and dispersed impact energy.