Research On The Compounding Technology Of High Performance Fiber For Bulletproof Laminate

To solve the problem of poor surface bonding performance of high-performance fibers used in bulletproof inserts and failure of composite systems during use,and to strengthen the structural integrity of bulletproof insertion plates after impact,surface modification and bonding performance of aramid Ⅲ and ultra-high molecular weight polyethylene(UHMWPE)fiber materials are carried out.The aramid fibre Ⅲ phosphate and coupling agent modification,UHMWPE fiber for the chromic acid and silica sol modified research.The surface properties and morphology changes of modified fiber materials were characterized by infrared spectroscopy(FT-IR),scanning electron microscope(SEM)and water contact angle test.The influence of the modification conditions and the composite process on the bonding performance were studied by tensile shear and T peeling strength tests,and compared and studied.The comprehensive properties of different adhesive composite systems are introduced.The main findings are as follows:(1)When phosphoric acid-modified aramid Ⅲ fiber is used,the oxidation of phosphoric acid introduces hydroxyl groups to the surface of aramid Ⅲ fibers to improve its infiltration;etching changes the structure of aramid Ⅲ fiber core to increase its surface roughness,which is conducive to improving its bonding strength.The phosphoric acid concentration has a greater impact on the bonding performance.When the phosphoric acid concentration is 30%,the bonding strength is the largest;the modification temperature and time of phosphoric acid have little effect on the bonding performance.The aramid Ⅲ fiber is pretreated with NaOH and then coated with the silane coupling agent KH550.The coupling coating and aramid Ⅲ fiber can form covalent bonds,improve the adhesion of the coupling coating,and also increase the surface roughness of the aramid Ⅲ fiber.The modified effect of coupling agent concentration of 5% and 40℃ is best.The bonding strength of aramid Ⅲ fiber after coupling agent modification is greater than that of phosphoric acid modification,so coupling agent modification of aramid Ⅲ fiber is selected(2)When using chromic acid to modify UHMWPE fibers,the oxidation of chromic acid introduces hydroxyl and carbonyl groups to the surface of the fiber,and the etching produces a gully on the surface of the fiber,which improves the infiltration performance.When the treatment temperature of chromic acid solution is less than 60 ℃,there is only etching effect on the fiber;when the temperature is higher than 60 ℃,the bond strength increases with the increase of temperature;the bond strength increases with the processing time,and the bond strength increases slightly after 7 minutes.The modified silicon sol coats the UHMWPE fiber and forms a water-friendly film on the surface of the fiber,which can improve the performance of its bonding interface and greatly improve the bonding strength of UHMWPE fibers.UHMWPE fiber is compounded with chromic acid and modified silicon sol,which has the best modification effect.The tensile shear strength has been increased from 1.27 MPa to2.49 MPa.(3)The results show that the tensile shear strength of aramid fiber Ⅲ modified by silane coupling agent and UHMWPE treated by composite treatment increases from 1.14 MPa to2.16 MPa,and the peel strength increases from 1.18n/mm to 2.20N/mm.(4)The composite system of EVA,TPU and PES has better low temperature resistance and water resistance,and the bond strength of the composite system of the three adhesives decreases greatly under the cycling temperature.In EVA is more suitable for three kinds of adhesive bonded aramid Ⅲ and UHMWPE fiber.(5)Research on the bonding process using EVA binder shows that the thicker the adhesive layer is,the lower the bonding strength will be.Good bonding strength can be obtained when the adhesive layer thickness is controlled at 0.1mm.The bonding strength of EVA adhesive for 3h curing at 90℃ is less than 1h curing at 120℃.Therefore,increasing temperature can shorten the curing time.When the curing temperature is 120℃,the curing time has little influence on the bond strength.