The US Army has announced a competition to design a new military uniform that can withstand fire and insect bites. A team of scientists at the University of Massachusetts managed to create a suitable material based on an existing nylon-cotton blend, treated with non-toxic chemicals.
A 50/50 nylon-cotton blend is commercially available and inexpensive, while the fabric is comfortable to wear, durable and resistant to wear and tear. To impart flame retardant properties, the mixture was treated with phytic acid, which is obtained from seeds, nuts and cereals. Scientists have focused on the cotton part of the blend because cotton has many hydroxyl groups on its surface that can be activated with readily available chemicals. This allows the hydroxyl groups to more easily bond with phosphorus-containing compounds, which impart fire resistance to the fabric.
The second step was the treatment of the tissue with permethrin, which by its action is a synthetic analogue of the natural repellent - chrysanthemum extract. The substance was applied to the fibers of the fabric by plasma deposition. Final tests showed that the nylon-cotton blend was 20% more fireproof and 98% more effective in repelling insects than untreated fabric. At the same time, it successfully retained its breathability, which is extremely important for all people subject to high physical exertion. Now scientists are planning to add antimicrobial properties to fabrics and improve the dyeing process, making it more resistant.