Technique for Measuring the Oxygen Index of Fibrous and Powdered Cellulose Derivatives

Abstract

A technique to assess the flame resistance of small quantities of fibrous or powdered derivatives of cotton cellulose was developed. The procedure is an adaptation of the oxygen index (OI) fabric flammability test. Cellulose fibers or powders were pressed into 0.5-g discs, 1 1/4 in. in diameter which were used to measure the OI's in the instrument employed for fabric OI determinations. Comparison of OI's of discs and fabrics representing untreated and conven tionally treated FR cottons resulted in a linear relationship; disc OI values were higher due to higher fiber density and lower accessibility of oxygen to the substrate. Among the experimental treatments of cotton cellulose, OI values of fibrous and powdered celluloses were uniformly low with increasing tritylation, peaked and dropped with increasing tosyl concentration and rose with increas ing mesylation. Some derivatives would be considered flame resistant.