Abstract
In previous papers, desirable conditions for cotton and viscose rayon fabrics were investigated on two representative durable flame retardant finishes, Pyrovatex and Proban finishes. The present paper reports the conditions for and the performance of an alternative durable flame retardant finish, namely heat cure of tetrakis (hydroxymethyl) phosphonium sulfate (THPS) monomer, for the fabrics.
The most adequate concentrations of THPS were found to be 25% for cotton and 30-32% for viscose, respectively, with some additives included. Effective additives were triethanolamine for pH adjustment, resins, glyoxal type one for cotton and melamine type one for viscose, for fixation of THPS on the fibers, and urea as an additional nitrogen source. As for the heating conditions, relatively long time heating, namely 20 min., at comparatively low temperature, 140°C, was found to be preferable compared with short time heatings, e.g., 5 min. at 150-160°C or higher. LOI values and tensile strengths of the fabrics finished by the three methods mentioned were compared. It was shown that the present finish gave better flame retardancies than Proban finish, and better tensile strengths than Provatex finish.
These results indicate that the heat cure method has certain advantages for practical applications.
