ISSN:
0022-3832
Keywords:
Chemistry
;
Polymer and Materials Science
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
,
Physics
Notes:
Redox recipes containing nitroprusside are described for the emulsion copolymerization of butadiene (75)-styrene(25). Approximately 65% conversion is reached in 8 hours at 25° with a recipe containing 5 parts of fatty acid soap, 0.3 part of sodium nitroprusside dihydrate, 0.1 part of hydroxylamine hydrochloride, 0.1 part of diisopropylbenzene hydroperoxide, 0.5 part of n-dodecyl mercaptan, and 0.5 part of potassium chloride per 180 parts of water and 100 parts of monomers. If alkali is added to the polymerization system the polymerization is accelerated markedly and the addition of 0.1 part of hydroxylamine does not affect the rate. Approximately 60% conversion is reached in 12 hours at 5°C. with a recipe similar to that given above, but without hydroxylamine, provided that the aqueous phase is 0.01 M in trisodium phosphate or alkali hydroxide. From the effect of various factors upon the rate of conversion it is postulated that in the low temperature recipe (with added alkali) the initiation occurs by RO · radicals: In the recipe without added alkali but with hydroxylamine hydrochloride the initiation apparently occurs by RS · radicals (RSH is mercaptan) formed by interaction of the oxidation product of nitroprusside with primary mercaptan.
Additional Material:
2 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/pol.1953.120110107
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