Polyamide copolymers with improved fire resistance
In the development of innovative textiles, one of the most important criteria for researchers is increased fire resistance. This is not only for the benefit of the consumer, but to keep pace with evolving European fire regulations. Consequently, the EU-funded NEREFITE project partners aimed to develop novel intrinsically flame retardant polyamides for testing on an industrial scale. Polyamide materials are basically composed of monomers (repeating units) joined by a peptide bond. This is a chemical arrangement that occurs naturally in wool and silk that has been mimicked and developed in materials such as nylon. NEREFITE aimed to improve on this by copolymerising another monomer with those that make up the Nylon architecture. In practice, manufacturers can choose from a huge range of monomers. The aim was to produce materials with low phosphorus content while incorporating a technique and chemical composition that eliminates problems of spinning as well as incorporating flame resistant properties. Project partners Rhodia, textile manufacturers, went on to search for appropriate monomers to add to the standard polyamide recipe and to refine the polymerisation process. Industrial trials were conducted on resultant materials and a yarn with a high degree of flame resistance containing an acceptable level of phosphorus and possessing spinnability was produced. Further research into the choice of monomer could pave the way towards developing innovative textiles with maximum safety features that can be manufactured on an industrial scale.
