Copolymers of Starch and Polyacrylonitrile. Influence of Granule Swelling on Copolymer Composition under Various Reaction Conditions
作者:
GeorgeF. Fanta,
RobertC. Burr,
C.R. Russell,
C.E. Rist,
期刊:
Journal of Macromolecular Science: Part A - Chemistry
(Taylor Available online 1970)
卷期:
Volume 4,
issue 2
页码: 331-339
ISSN:0022-233X
年代: 1970
DOI:10.1080/00222337008063152
出版商: Taylor & Francis Group
数据来源: Taylor
摘要:
Molecular weights and grafting frequencies of graft copolymers prepared with ferrous ammonium sulfate-hydrogen peroxide initiation showed a dependence on granule swelling similar to that found with ceric ammonium nitrate (increased swelling of starch granules decreased the number of grafted polyacrylonitrile chains and increased their average molecular weight). As with unswollen starch, the composition of the copolymer prepared from swollen starch was not influenced by granule size. Molecular weights of polyacrylonitrile branches grafted to swollen and unswollen starch were independent of reaction time; however, grafting frequencies with swollen and unswollen starch tended to converge toward a common value with increased reaction time and increased dilution. Data suggest that the influence of granule swelling on copolymer composition is due to a faster termination rate for growing polyacrylonitrile chains in unswollen starch.
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