Starch‐g‐Poly(Methyl Acrylate) Latexes for Stabilizing Soil to Water Erosion: Extending the Range of Polymer Add‐On

Cationic starch‐ g ‐polymer latexes stabilize soil particles to water. To extend the study of such utility of starch latexes we prepared starch‐ g ‐poly(methyl acrylate) (S‐ g ‐PMA) and cationic starch‐ g ‐poly(methyl acrylate) (CS‐ g ‐PMA) latexes by the ceric‐initiation procedure, varying the weight ratio of starch or cationic starch to methyl acrylate from (10 to 1) to (1 to 1) in the preparation step. The percent add‐on (percent synthetic polymer in the graft copolymer) ranged from 0.5% to 41% for S‐ g ‐PMA, and from 4.6% to 43% for CS‐ g ‐PMA. Application rates required to obtain stable soil are dictated by the amount of PMA in the graft copolymer. For instance, wet sieve testing showed that 10S‐ g ‐1PMA and 10CS‐ g ‐1PMA latexes required dose levels of 0.4 g/100 g soil to fully stabilize the test soils. (6–8)S‐ g ‐1PMA and (6–8)CS‐ g ‐1PMA latexes gave full stabilization when applied at 0.1 g or 0.2 g/100 g soil rate. Latexes with highest (24.4%–43%) add‐on stabilized soil fully at an application rate of 0.1 g/100 g soil or less. There was no clear advantage of CS‐ g ‐PMA over S‐ g ‐PMA.