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Kinetics of the Benzylation of Potato Starch
Author(s) -
Free H. W. Homan,
Joosten G. E. H.,
Roelfsema W. A.,
Stamhuis E. J.
Publication year - 1985
Publication title -
starch ‐ stärke
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.62
H-Index - 82
eISSN - 1521-379X
pISSN - 0038-9056
DOI - 10.1002/star.19850370105
Subject(s) - starch , chemistry , potato starch , benzyl alcohol , suspension (topology) , ether , organic chemistry , ion , electrolyte , base (topology) , kinetics , polymer chemistry , catalysis , mathematical analysis , physics , mathematics , electrode , quantum mechanics , homotopy , pure mathematics
The formation of benzyl ethers of potato starch by etherification with benzyl chloride is base catalyzed and is therefore carried out at high pH. In a suspension of starch granules the rate of starch ether formation is found not to be linearly related to the concentration of hydroxyl ions in the water phase of the suspension. At the same pH widely different rates of reaction can be observed, to be due to the tendency of the starch granules to “absorb” hydroxyl ions when electrolytes are added to the suspension. The rate of formation of the benzyl ether of starch is found to be linearly related to the amount of hydroxyl ions “absorbed” by the starch. The rate of the side reaction leading to benzyl alcohol turned out to be higher in the presence of starch than in water of the same pH.