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Graft polymerization of styrene onto starch by simultaneous cobalt‐60 irradiation
Author(s) -
Fanta George F.,
Burr Robert C.,
Doane W. M.,
Russell C. R.
Publication year - 1977
Publication title -
journal of applied polymer science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.575
H-Index - 166
eISSN - 1097-4628
pISSN - 0021-8995
DOI - 10.1002/app.1977.070210209
Subject(s) - styrene , polystyrene , copolymer , polymerization , polymer chemistry , ethylene glycol , solvent , chemistry , dimethylformamide , starch , materials science , polymer , acetone , organic chemistry
Starch‐ g ‐polystyrene copolymers have been prepared by the simultaneous 60 Co‐irradiation of starch–styrene mixtures, and copolymers have been characterized with respect to weight per cent polystyrene (% add‐on) and also the molecular weight and molecular weight distribution of polystyrene grafts. In a typical polymerization, 4 g each of starch and styrene were blended with 1 ml water and 1.5 ml of an organic solvent; the resulting semisolid paste was irradiated to a total dose of 1 Mrad. With ethylene glycol, acetonitrile, ethanol, methanol, acetone, and dimethylformamide as the organic solvent, values for % add‐on ranged from 24% to 29%. The highest % add‐on (43%) and the highest conversion of styrene to grafted polymer (76%) were obtained when the organic solvent was omitted, and water alone was used. When water was also omitted, polymerization of styrene was negligible; however, graft copolymer was formed in the absence of water when either ethylene glycol or ethanol was added. Attempts were unsuccessful to achieve a % add‐on greater than 43% by doubling the amount of styrene in the polymerization recipe. Mixtures of equal weights of starch and styrene are relatively nonvicious, but these mixtures thicken when either water or ethylene glycol is blended in. Reasons for this thickening action and the possible influence of thickening on the graft polymerization reaction were explored.