Study On Preparation And Properties Of STF/CNTs Enhanced Composite Protective Materials

Kevlar fiber and ultra-high molecular weight polyethylene（UHMWPE）fiber are widely used in the field of protection because of their high strength,low density,good toughness and puncture resistance.In order to further improve the protective properties of fiber materials,make it have better protective effect.In this paper,STF/CNTs/Kevlar and STF/CNTs/UHMWPE composites were prepared by synergizing STF with CNTs to strengthen high-performance Kevlar and UHMWPE fiber materials.STF with dispersion medium of PEG400 and Si O₂mass fraction of 10%,20%and30%was prepared by mechanical stirring method combined with ultrasonic dispersion.The influence of viscosity-shear rate relationship on STF was studied.CNTs were prepared with concentrations of 6mg/m L,8mg/m L,10mg/m L and 12mg/m L,respectively.The absorbance of CNTs was tested by ultraviolet spectroscopy to analyze the dispersion of CNTs.CNTs/Kevlar and CNTs/UHMWPE composites were obtained by spraying the CNTs dispersion solution with a concentration of 10mg/m L on the surface of Kevlar and UHMWPE.CNTs/Kevlar and CNTs/UHMWPE composites were impregnated into STF with Si O₂mass fraction of 20%by impregnation method to obtain STF/CNTs/Kevlar and STF/CNTs/UHMWPE composites.The morphology of the composites was characterized by scanning electron microscopy（SEM）,and the structure of the composites was characterized by Fourier infrared spectroscopy.It was determined that CNTs were attached to Kevlar and UHMWPE fibers,and STF was well combined with CNTs/Kevlar and CNTs/UHMWPE composites.The static tensile test of Kevlar,UHMWPE fiber and CNTs/Kevlar,CNTs/UHMWPE,STF/CNTs/Kevlar,STF/CNTs/UHMWPE composite was carried out.The results show that STF/CNTs/Kevlar and STF/CNTs/UHMWPE composites have better tensile strength than single Kevlar and UHMWPE fibers.The drop weight impact test was used to test single Kevlar,UHMWPE fiber and CNTs/Kevlar,CNTs/UHMWPE,STF/CNTs/Kevlar,STF/CNTs/UHMWPE composites.The results show that compared with single Kevlar and UHMWPE fibers,the composite can resist impact more effectively.LS-DYNA finite element analysis software was used to perform numerical simulation of impact tests on composites.The initial velocity was set to 2.135m/s,and the composite did not penetrate the phenomenon,and compared with the results of the drop weight impact experiment,the absorption energy curve was basically consistent with the change of the remaining velocity curve of the punch,and the data error was within 15%.Compared with single Kevlar and UHMWPE fibers,the impact resistance of STF/CNTs/Kevlar,STF/CNTs/UHMWPE composites is significantly improved,and the impact resistance is more effective.