Determination of Trivalent Phosph rus in Flame-Retardant Textiles

Abstract

The concentration of trivatent phosphorus P(III) in flame-retardant (FR) cotton and FR cotton/polyester blends can be determined indirectly by measurement of iodide with an iodide-ion-selective electiode. The amount of iodide measured is directly related to the H 2O2 used to oxidize the P(III) of the FR finish to pentavalent phosphorus P(V). The electrode method eliminates problems associated with the titrimetric determination of I2. The electrode method is applicable to the determination of P(III) in FR finishes prepared by THPC/urea, THPOH/urea/TMM, and THPOH/ NH3 processes.