The Study Of Anti-impacted Composite Materials Based On Aramid And High Strength Polyethylene

Aramid fiber and high strength polyethylene fiber belong to high performance fibers. The study of using two kinds of fiber raw materials to weave three dimensional woven fabric complexed with shear thickening fluid(STF) is currently very few. In this paper,the double layer spacing, three interval and triangular cross section hollow tructure fabric were developed with two kinds of high performance fiber. At the same time, the fabric surface was modified by silane coupling agent and the anti-impacted composite materials was formed by the shear thickening fluid(STF).The fabrics were weaved by 1670 dtex aramid fiber and high-strength polyethylene fiber. The single-tightness of fabric was 33%, the weft tightness was 25% and metric reed number was 20. Three different structures were weaved by the two sample looms in the laboratory, including double spacer fabric, three layer interval fabric and a triangular cross-section hollow fabric.The surface of aramid fiber and high strength polyethylene fiber was modified by silane coupling agent, and the optimum scheme of two fibers modification was obtained by the single factor analysis. The concentration of silane coupling agent was 5%, the processing temperature was 62.5 ℃ and the processing time was 5h. The optimum scheme was used to deal with the fiber of the aramid fiber and high strength polyethylene. At the same time, the changes of the surface structure and wettability of two kinds of fibers were compared by SEM and fiber contact angle measuring instrument. The results show that the aramid fiber after modified, fiber surface vertical engraved mark and adhering to the surface of some of the material. But the high-strength polyethylene after treatment, the groove of the surface become more, deeper, more regular and obvious longitudinal notch.The surface roughness of the fibers has been increased, and its wettability is improved by different degrees of increase.In order to form the shear thickening fluid, the nano Si O2 particles that was used as dispersed phase and polyethylene glycol 400(PEG400) that was used as the dispersion medium. By mechanical agitation, ultrasonic dispersion and mechanical oscillation joint action forming different concentrations 9%, 12%, 15%, 17%, 20% shear thickening fluid(STF). It is found that different dispersed phase particle concentration, dispersion medium and temperature changes affect rheological properties of dispersion system the dispersionsystem. The good shear thickening effect was made, and good shear thickening effect STF system was obtained.The tensile properties of the fabric and STF flexible composites were tested by universal testing machine and analyzed the data. The results is as follows:For double spaced structure, the warp average tensile strength of the STF treated fabrics are increased by 82.254 MPa than the fabric. But the weft average tensile of the STF treated fabrics are increased by 106.064 MPa than the fabric. For three interval structure, the warp average tensile strength of the STF treated fabrics are increased by 92.322 MPa than the fabric, but the weft average tensile of the STF treated fabrics are increased by 74.352 MPa than the fabric. For triangular cross section hollow structure, the warp average tensile strength of the STF treated fabrics are increased by 61.064 MPa than the fabric, but the weft average tensile of the STF treated fabrics are increased by 41.174 MPa than the fabric. And then,The dynamic impact properties of three different structural fabrics are tested by the self-made drop hammer test device and analyzed. The experimental results show that: after the low impact resistance ability of STF treated fabrics is better than the fabric. When the hammer fell on the fabric surface, shear thickening fluid appear shear thickening phenomenon so that the fibers friction between the filaments and the beam have increased.Thereby its dynamic stab impact properties is improved.