Revision on the Titration Method for Accurately Measuring the Amounts of Residual Monomers in Polyacrylic Sizes

Abstract

An attempt has been made to develop a revised titration method for accurately measuring the content of residual monomers in polyacrylic sizes. It was found that the conventional titration method widely used nowadays for the content measurement cannot determine the content accurately if a certain number of hydrophobic structural units are contained in the size macromolecules. Since most mills and size companies do not possess a chromatograph, a revised titration method is studied and proposed. By choosing three to four sample weights in the range of 0.1— 0.6 g to achieve three to four corresponding values of the monomer content, a straight regression line can be easily obtained in a coordinate. The ordinate value of intersection of the line with ordinate is just the measured value. A gas chromatograph demonstrates that the revised method is suitable for the determination of the content when the polymeric molecules of the sizing agents incorporate hydrophobic constitutional units. The effectiveness and accuracy of the revised method are examined by mixing a known amount of monomer into the sizes. The results demonstrate that the regression and chromatograph values are correlated well and the differences are relatively small. The accuracy of the revised method is much higher than that of the original one.