Effects of carboxyl content on the characteristics of TMP long fibers

This work examined the effects of carboxyl content on the characteristics of TMP long fibers. The carboxyl groups on TMP long fibers were generated by a TEMPO-mediated oxidation using different amounts of sodium hypochlorite. In general, the increases in carboxyl content improved the tensile and burst indices but reduced the tear index and fines retention. It was also found that low carboxyl content on oxidized long fibers could adsorb part of the dissoluble substance (DS) and other substances, reducing the DS and total organic carbon (TOC) in whitewater; the adsorption capacity decreased with increasing carboxyl content. Addition of cationic polymer increased the retention of fines and decreased the DS and other substances in whitewater.