Soft body armor is usually made of fabrics such as aramid and ultra-high molecular weight polyethylene fibers. Their puncture resistance depends on the friction between the yarns and fibers inside these materials. To some extent, greater friction means greater protection.

Researchers reported in ACS Applied Nano Materials that carbon nanotubes and polyacrylates reinforced traditional aramid to produce lightweight, soft fabrics that provide better protection.

Additional components can be added to enhance the adhesion between yarns, such as pure thickener (STF) or polyurethane (PU) coating. The researchers tested polyacrylate lotion (PAE), STF and PU as coatings for aramid fabrics. In simulated puncture tests, aramid fabrics coated with PAE exhibit better performance than uncoated materials used alone or in combination with STF or PU.

As is well known, carbon nanotubes can make composite materials more tough, and adding them to aramid can further improve their impact resistance. The research team suggests that this is because carbon nanotubes establish bridges between fibers, thereby increasing friction. Carbon nanotubes also form a thin protective mesh, dispersing stress from the impact point and helping to prevent fiber disintegration.