| The main goal of this research project was to compare the retention and drainage enhancement characteristics of commercial amphoteric starch with cationic pulp fines. The pulp fines were cationized by reacting them with 3-chloro-2-hydroxypropyl trimethylammonium chloride. The amphoteric starches used in these experiments had a degree of substitution (DS) of 0.021 and 0.028. Two samples of pulp fines were prepared, having a DS equal to that of the starch and another ten times greater. The retention and drainage characteristics of two different papermaking stocks (one containing clay at pH 4.5, another with CaCO;The maximum degree of substitution for the pulp fines of 0.8 approximately was achieved. In all cases, the addition of either cationic fines or starch improved the retention. No correlation was seen between the zeta potential of the fines and the colloidal titration ratio of those fines. (Abstract shortened by UMI.)... |
