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Darstellung der Carboxymethylstärke
Author(s) -
Čeh M.
Publication year - 1972
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.19720240406
Subject(s) - starch , chemistry , sodium hydroxide , acetone , aqueous solution , solubility , salt (chemistry) , viscosity , alkali metal , nuclear chemistry , sodium , yield (engineering) , maize starch , intrinsic viscosity , polymer chemistry , inorganic chemistry , organic chemistry , polymer , materials science , metallurgy , composite material
Abstract Synthesis of Carboxymethyl Starch. Maize starch was carboxymethylated by monochloracetic acid in a mixture of 25 % aqueous sodium hydroxide solution and acetone. Using a ratio of starch to monochloracetic acid of 2:1 at 20 °C for 11 h the yield was 60 % (DS 0.59), and at 40 °C 82 % (DS 0.81). The synthesis of the sodium salt of carboxymethylated starch in aqueous alkali solution without acetone at room temperature gave poor results. Reaction of the substances in solid, ground state resulted in ethers with low solubility in water. Viscosity measurements of 2% solutions of the sodium salt of carboxymethylated starch in 1 N NaOH without elimination of the electrolytes revealed a correlation between viscosity and degree of substitution only in case when the ethers have been synthesized and isolated by the same method.