Study on impact resistance of Nano‐SiO2 reinforced STG/Kevlar composites

• Published in: Polymer engineering and science Vol. 62; no. 8; pp. 2569 - 2579
• Main Authors: Lin, Huan, Chen, Guojing, Li, Wanli, Cai, Lihai, Liu, Wenyan
• Format: Journal Article
• Language: English
• Published: Hoboken, USA John Wiley & Sons, Inc 01.08.2022; Blackwell Publishing Ltd
• Subjects: Aramid fiber reinforced plastics; Bearing capacity; composite material; Composite materials; Impact resistance; Impact tests; Impregnation; Kevlar (trademark); particle enhancement; Projectiles; Shear thickening (liquids); shear thickening gel (STG); Silicon dioxide; Thickening
• ISSN: 0032-3888; 1548-2634
• DOI: 10.1002/pen.26042

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. A novel STG/SiO2/Kevlar flexible protective composite was prepared by impregnating STG/SiO2 into Kevlar. SiO2 improved the integrity and impact resistance of STG/SiO2/Kevlar composites by enhancing the shear‐thickening properties of STG and the friction during yarn sliding.