By Cameron Chai
Texas A&M University researchers have demonstrated that polymer-based 'nano intumescent' can be utilized as flame retardants for fabrics used in childrens wear as it is less toxic than existing retardants.
According to Jaime C. Grunlan, who heads the research team, the water-based elements in this novel nano coating are eco-friendly and have less toxicity to humans compared to existing brominated or halogenated flame retardants.
The research team has adopted ‘intumescence’, a technology that has been utilized for a long time to fireproof internal steel beams in buildings. When a flame touches an intumescent coating, it swells up and grows like beer foam, creating small bubbles in a protective shield that protects and insulates the material underneath.
The nanomaterial is made of alternate layers of negatively and positively charged polymers at the nanoscale. Due to their nanosize, the polymer liquid penetrates deep into the cotton fabric and forms a coating over every individual cotton fiber. During the exposure of the novel nano coating to a flame, it swells mildly and prevents the fire from burning the fabric ensuring that the fabric states white, excepting the tiny area where the cotton is in contact with the flame. Presently available flame retardants though may inhibit the flames spreading but the fabric gets completely burnt and truns black.
Grunlan stated that the texture and appearance of the cotton fabric would be based on the type of polymer utilized and the coating thickness. Exchanging one of the positively or negatively charged polymers with another polymer could make the fabric softer, while offering same anti-flammable protection.
At present, Grunlan's team is working on optimizing the flame retardant in order to retain it on cotton fabric even after regular laundering. The team also intends to experiment the nano coating on other materials, including foam and polyester, probably with commercial partners.