Scientists at North Carolina State University have found new ways to make protective fabrics - such as those used in flame-retardant children's clothing or odor-inhibiting socks and shirts - last longer and work better.
Instead of treating the surface of the fabrics with protective polymer coatings that can wear thin and lose effectiveness from use or repeated washing, the NC State researchers are imbedding the polymers that make up the fabric itself with various additives. Laboratory tests show that fabrics and films made this way provide greater protection and retain their flame-retardant or antibacterial qualities longer than materials treated with conventional surface coatings.
The new process could be used on fabrics and films in a wide range of products, from children's clothing and odor-inhibiting socks and shirts, to antibacterial medical gowns, dressings and sutures.
The research team is headed by Dr. Alan Tonelli, KoSa professor of polymer science at NC State's College of Textiles.
In the new process, Tonelli and his students first form an inclusion compound - a high-temperature crystal that contains the desired polymer additives. This "host crystal," as Tonelli calls it, typically is made of cyclodextrins, cyclic starch molecules composed of interlocked glucose sugar rings. Cyclodextrin molecules have a hole in their centers, much like doughnuts, and naturally stack one on top of another to form long tubes into which the additives are imbedded.
After Tonelli and his students form the cyclodextrin-inclusion compound, they melt-press the crystals into a polyester film. Tests have shown a significant increase in the flame retardancy of polyester films created this way.
"We were convinced, just based on these results, that this is much better, much more effective and should provide longer lasting protection," Tonelli said. Since the crystals are part of the film or fabric, washing would have far less of a
Contact: Dr. Alan Tonelli
North Carolina State University