THE LOCATION OF XANTHATE GROUPS IN PARTIALLY SUBSTITUTED STARCH XANTHATES

Author:

Adamek E. G.,Purves C. B.

Abstract

The rate of xanthation of starch with carbon disulphide in 17.8% potassium hydroxide at 23° was followed by converting the potassium salts to the S-methyl xanthate esters, and analyzing the latter for sulphur. These esters were tritylated without changing the xanthate D.S., and unity minus the trityl D.S. was assumed to represent xanthate D.S. in the primary alcohol positions of the starch. About 62% of the xanthate groups occupied secondary positions after 100 minutes of xanthation, but after 3350 minutes about 58% of the surviving xanthate groups were primary.A sodium chlorite–pyridine–lactic acid mixture reduced the sulphur content of a fully acetylated starch S-methyl xanthate by about nine-tenths with little loss of acetyl groups, but the residual sulphur could not be eliminated and the resulting starch acetate could not be completely reacetylated or tosylated. The location of the hydroxyl groups in this acetate thus could not be studied by the tosylation–iodination method.

Publisher

Canadian Science Publishing

Subject

Organic Chemistry,General Chemistry,Catalysis

Cited by 9 articles. 订阅此论文施引文献 订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献

1. CHEMICAL MODIFICATION OF STARCH;Advances in Carbohydrate Chemistry and Biochemistry;2004

2. Substitution Patterns of Polysaccharide Derivatives;Polysaccharides - Syntheses, Modifications and Structure/Property Relations;1988

3. STARCH DERIVATIVES: PRODUCTION AND USES;Starch: Chemistry and Technology;1984

4. Sulfur Containing Starches;Starch - Stärke;1982

5. Physicochemical and macromolecular properties of sodium amylose xanthate in dilute solution;Journal of Polymer Science Part A-1: Polymer Chemistry;1968-05

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