Polymer Distribution in Grafted Starch Granules by Scanning Electron Microscopy

Autor: Robert C. Burr, J. A. Stolp, F. L. Baker, William M. Doane, George F. Fanta
Rok vydání: 1976
Předmět:
Zdroj: Starch - Stärke. 28:382-386
ISSN: 1521-379X
0038-9056
DOI: 10.1002/star.19760281105
Popis: The location of grafted polymer within the starch granule matrix was determined by scanning electron microscopy for two wheat starch graft copolymers prepared by 60Co-initiated graft polymerization of a mixture of acrylamide and N,N,N-trimethylaminoethyl metacrylate methyl sulfate (TMAEMA-MS). For a graft copolymer containing 16% synthetic polymer, prepared by the simultaneous irradiation of a starch-monomer mixture, grafting took place throughout most of the granule interior. However, a graft copolymer containing 31% synthetic polymer, prepared by reaction of preirradiated starch with a water solution of monomers, was grafted largely near the granule surface. In contrast to starch-g-poly(acrylamide-co-TMAEMA-MS) prepared by simultaneous irradiation, irradiation of a starch-styrene mixture gave predominantly surface grafting. All graft copolymers had the outward appearance of starch granules, and this appearance was retained even after removal of the starch moiety by hydrolysis. The size distribution of wheat starch granules, as determined by Coulter counter measurements, was not greatly altered by graft polymerization of acrylamide-TMAEMA-MS; however, graft polymerization of styrene onto corn starch significantly increased granule size.
Databáze: OpenAIRE
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