Wool is popular in apparel, industrial applications and interior textiles due to its good comfort, absorbency, antistatic, colouration and warmth retention properties as well as a high degree of inherent non-flammability (1). However, some special products such as seat coverings in cars and buses, aircraft furnishings and blankets, and military textiles need additional treatment to impart higher flame-resistance to them.
Phosphorus-containing cellulosic flame retardants, halogen compounds, zirconium and titanium metal complexes and sulphur containing flame-retardants have been applied to the flame retardant treatments of wool textiles (4). As many halogenated products are carcinogenic or produce highly toxic and corrosive gases with great amounts of smoke in combustion, they have been legally banned. The Zirpro treatment, which is based on the exhaustion of negatively charged zirconium and titanium complexes onto positively charged wool under acid conditions, has become the most commonly used flame retardant process (5, 6). However,the heavy metal ions of zirconium/titanium existing in both Zirpro-treated wool textiles and effluent discharges could cause environmental issues. They should be gradually replaced by environmentally friendlier flame retardants. In this study, a bio-based phosphorus-containing phytic acid (PA) (Figure 1) as an eco-friendly agent was used to enhance the flame retardancy of wool fabric.
PA is extracted from beans, cereals, oilseeds and organic soils (7, 8). It has been successfully used as antioxidant,anticancer agent, biosensor, cation exchange resin and nanomaterial because of its special inositol hexaphosphate structure (8). PA contains 28 wt% phosphorus based upon molecular weight, and is promising as one of possible and effective flame retardant materials. Recently, PA as a nontoxic naturally occurring and phosphorus-containing compound has provoked people’s interest in the flame retardant finishing of textiles, and found its application in the flame retardant modification of cellulosic materials (cotton fabric and paper) via different methods (7, 8).
