Surface modification of kevlar fabric with a novel sulfonyl aryl containing monomer and its influence on inter yarn friction

Abstract

The ballistic impact response of Kevlar textiles is significantly influenced by the friction between the yarns. It increases the dissipation of energy when yarns begin to displace relative to one another and it also results in to transfer of load to a larger area during ballistic impacts. In the present work, a novel sulfonyl aryl group containing monomer acrylic acid-2-(toluene sulphonyl amine)-ethyl ester (AATSAEE) was synthesized by a three-step process with ethanol amine and p-toluene sulfonic acid as starting material. The monomer was homopolymerized and grafted on Kevlar fabric by UV-induced free radical polymerization technique. Benzoyl peroxide (BPO) was used as initiator. Utilizing spectroscopic and thermal gravimetric methods, the monomer, precursor, and the homopolymer were characterized. The yarn pull-out tests on unmodified and AATSAEE grafted Kevlar fabrics were performed on Universal Tensile Tester at a steady speed of the upper jaw of 50 cm min−1. Increases in yarn pull out force have been noted with grafting of AATSAEE on Kevlar fabric. The peak force increases around 284% with grafting which indicates an increase in friction forces. When these yarns start to move apart from one another due to friction factors, the fabric’s energy dissipation increases and it may results in to increase in energy absorption at the time of ballistic impacts.