Cereal Chem 69:237-239   |  VIEW ARTICLE

Cationic Oat Starch: Preparation and Effect on Paper Strength.

W. J. Lim, Y. T. Liang, and P. A. Seib. Copyright 1992 by the American Association of Cereal Chemists, Inc. 

Cationic ethers were prepared from oat starch by reaction with 32-chloro-3- hydroxypropyltrimethylammonium chloride at alkaline pH. The reaction of starch (approximately 35% solids) in a mixture of 0.50 M Ca(OH)2 and 0.49M Cacl2 at 25 C for 20 hr with 50 mmol of cationic reagent per millmole of anhydroglucose unit gave cationic oat starch with a degree of substitution (DS) of 0.014. When the reaction was done in 0.48M NaOH and 2.43M Na2SO4, the DS of the product was 0.042. In the calcium ion system, reacting beyond 8 hr at 35 C, 3 hr at 40 C, or 24 hr at 25 C caused gelation of the mixture. Cationic oat starch, corn starch, and wheat starch, all with DS of approximately 0.013, improved the dry strength of paper handsheets to a comparable degree. Cationic oat and wheat starches prepared in CaCl2/Ca(OH)2 gave higher Scott bond and burst indices than those prepared in NaOH/Na2SO4.