Dyeing of chemically modified celluloses. II. Effect of chemical modification of cellulose on the dyeing properties of some direct dyes

The behavior of partially acetylated cellulose, partially carboxymethylated cellulose, cyanoethylated cellulose, and cellulose grafted with polyacrylontrile toward three direct dyes, namely, Chlorantine Fast Red 6 BLL, Solophenyl Orange T4RL, and Diphenyl Brilliant Flavine 7GFF, was studied. Partially acetylated cellulose having 2.06% combined acetic acid showed higher dye uptake than the unmodified cellulose. The amount of dye uptake increased as the acetyl content increased up to 4% combined acetic acid. Beyond this, enhancement in the dye uptake was not significant. Whereas partially carboxymethylated cellulose showed a lower dye uptake than the control. The dye uptake decreased considerably as the carboxymethyl groups increased. The same holds true for cyanoethylated cellulose where increasing the cyanoethyl content caused a substantial reduction in the dye uptake. On the other hand, cellulose grafted with polyacrylonitrile up to 18.3% graft yield showed much higher dye uptake than the ungrafted cellulose.