Evaluation of Laundering Durability of Electro-conductive Textile Dip-coated on Para Aramid Knit with Graphene/Waterborne Polyurethane Composite

This study aims to fabricate an electro-conductive textile dip-coated with graphene/waterborne polyurethane (WPU) composite, and an evaluation of the laundering durability of this composite was conducted in order to confirm the application of the protective clothing. Samples were coated five times on the para-aramid knit with the graphene/WPU composite by the dip-coating method, and then hot-pressed processes were applied with various temperatures. The samples were washed 5, 10, 15, and 20 times, and then, morphology, surface resistance, and surface temperature were measured. After five laundering cycles, control and hot-pressed samples maintained surface resistivity from 10 kΩ/sq to 100 kΩ/sq. The surface resistivity of the control sample, however, was gradually increased up to 20 laundering cycles. The sample that was hot-pressed at 120 °C showed the lowest value of about 15 kΩ/sq with almost no variation from zero laundering cycles to 20, thus, it is the most stable sample up to 20 laundering cycles. When applied voltage at 50V, the surface temperature of the nonlaundering samples was presented as over 40.0 °C. In the case of the control sample, there was almost no electrical heating performance remaining after the fifth laundering test, but the hot-pressed samples maintained 40.0 °C or more at 50 V after the 10th laundering test. The sample that was hot-pressed at 120 °C in particular could maintain electrical heating performance at about an 80 % level up to the 10th laundering cycle. Therefore, the sample that was hot-pressed at 120 °C was the most stable in terms of electrical properties after 20 laundering cycles, and its electrical heating performance could be maintained even after 10 laundering cycles. It is expected that this process can be applied and used to make functional clothes for apparel and other applications.