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As a flexible protective material, shear thickening gel (STG)/Kevlar composite still has great potential to improve its impact resistance. In this paper, a novel STG/Si[O.sub.2]/Kevlar flexible protective composite was prepared by impregnating STG/Si[O.sub.2] into Kevlar. Due to the excellent Si[O.sub.2] enhancement effect, the STG/Si[O.sub.2]/Kevlar exhibited a higher safeguarding property than the STG/Kevlar. The maximum yam pull-out force of STG/Si[O.sub.2]/Kevlar reached 61.7 N, which was higher than the 41.9 N of STG/Kevlar. The uniform puncture results showed that the maximum bearing capacity of STG/Kevlar and STG/Si[O.sub.2]/Kevlar increased by 116.8% and 215.3%, respectively, compared with pure Kevlar. The impact test results indicated that 20 layers of STG/Si[O.sub.2]/Kevlar could not be penetrated by the knife stab and 24 layers of STG/Si[O.sub.2]/Kevlar could not be penetrated by 7.62 mm pistol bullets. Finally, the enhancement mechanism of impact resistance of STG/Si[O.sub.2]/Kevlar composites was studied. KEYWORDS composite material, impact resistance, particle enhancement, shear thickening gel (STG), 1 | INTRODUCTION Body armor or stab-resistant clothing is usually made of layers of high-performance fiber fabrics superimposed and sewn to achieve a protective effect, which seriously reduced the comfort [...]

As a flexible protective material, shear thickening gel (STG)/Kevlar composite still has great potential to improve its impact resistance. In this paper, a novel STG/SiO2/Kevlar flexible protective composite was prepared by impregnating STG/SiO2 into Kevlar. Due to the excellent SiO2 enhancement effect, the STG/SiO2/Kevlar exhibited a higher safeguarding property than the STG/Kevlar. The maximum yarn pull‐out force of STG/SiO2/Kevlar reached 61.7 N, which was higher than the 41.9 N of STG/Kevlar. The uniform puncture results showed that the maximum bearing capacity of STG/Kevlar and STG/SiO2/Kevlar increased by 116.8% and 215.3%, respectively, compared with pure Kevlar. The impact test results indicated that 20 layers of STG/SiO2/Kevlar could not be penetrated by the knife stab and 24 layers of STG/SiO2/Kevlar could not be penetrated by 7.62 mm pistol bullets. Finally, the enhancement mechanism of impact resistance of STG/SiO2/Kevlar composites was studied. [ABSTRACT FROM AUTHOR]

In order to understand the effect of structure on the tensile properties of lay-flat hose fabric reinforcement layer, the weft tensile process of fabrics with different structures was simulated by finite element method. The accuracy of the simulation method is verified by comparing the results of tensile test and finite element simulation. The effects of warp spacing, weft thickness, weave pattern and weft shrinkage on the tensile properties of the fabric are studied. Combined with the simulation results, the influence of fabric structure on the compression strength of lay-flat hose is analyzed. The results show that the larger the warp spacing, the finer the weft, the smaller the weft crimp rate, the greater the weft tensile modulus of the fabric, and the less prone to tensile deformation. The weft tensile modulus of twill fabric is greater than that of plain fabric. The crimp rate of double-layer twill fabric is smaller than that of single-layer plain fabric and twill fabric, and it is not easy to deform, so the pressure bearing strength of lay-flat hose with double-layer twill fabric as reinforcement layer is higher. [ABSTRACT FROM AUTHOR]

A poly(butylene succinate-co-butylene adipate)/TiO2 (PBSA/TiO2) nanocomposite was prepared by a melt-blending process. The effect of TiO2 nanoparticles on the photodegradation behaviors of the nanocomposite was investigated by transmission electron microscopy (TEM), differential scanning calorimetry (DSC), Fourier-transform infrared spectroscopy (FT-IR), field-emission scanning electron microscopy (FE-SEM), rheological measurements, and mechanical tests. TEM images of the PBSA/TiO2 revealed that the TiO2 nanoparticles were well dispersed in the matrix without obvious aggregation. The FT-IR results indicated that the TiO2 nanoparticles can block high-energy ultraviolet (UV) light and reduce the degradation of the PBSA matrix. The viscosity analysis results indicated that the TiO2 nanoparticles inhibited the chain scission of PBSA matrix under irradiation. In addition, the surface of the PBSA/TiO2 films and their mechanical properties change less than that of untreated PBSA films during the photoaging process. The obtained results imply that the TiO2 nanoparticles can be considered as an efficient photodegradation-resistant additive to PBSA for reducing photodegradation. [ABSTRACT FROM AUTHOR]