Hydrolyzed starch–polyacrylonitrile graft copolymers: Effect of structure on properties

Authors

  • M. O. Weaver,

    1. Northern Regional Research Laboratory, Northern Marketing and Nutrition Research Division, Agricultural Research Service, U.S. Department of Agriculture, Peoria, Illinois 61604
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  • L. A. Gugliemelli,

    1. Northern Regional Research Laboratory, Northern Marketing and Nutrition Research Division, Agricultural Research Service, U.S. Department of Agriculture, Peoria, Illinois 61604
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  • W. M. Doane,

    1. Northern Regional Research Laboratory, Northern Marketing and Nutrition Research Division, Agricultural Research Service, U.S. Department of Agriculture, Peoria, Illinois 61604
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  • C. R. Russell

    1. Northern Regional Research Laboratory, Northern Marketing and Nutrition Research Division, Agricultural Research Service, U.S. Department of Agriculture, Peoria, Illinois 61604
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  • Presented at the Fifth Great Lakes Regional Meeting of the American Chemical Society, Peoria, Illinois, June 10–11, 1971.

Abstract

Three starch–polyacrylonitrile (S–PAN) graft copolymers containing ratios of S:PAN of 1:1.90, 1:1.16, and 1:0.64 were prepared by graft polymerization of acrylonitrile onto gelatinized starch. A fourth graft, made from granular starch, had an S:PAN ratio of 1:2.16. These grafts were hydrolyzed in potassium hydroxide under various conditions to give a series of products with varying amounts of carboxylic acid and amide groups. Maximum conversion of nitrile to carboxyl was 65%. Aqueous dispersions of the hydrolyzed S–PAN's at pH 7–8.5 were viscous, and, in general, their viscosities reflected the amount of PAN add-on, with the highest add-on giving the highest viscosity. Plots of the η/C versus C show that hydrolyzed S–PAN's from gelatinized starch behave as normal polyelectrolytes on dilution to low concentration but that S–PAN from granular starch does not.

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