ISSN:
0022-3832
Keywords:
Chemistry
;
Polymer and Materials Science
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
,
Physics
Notes:
The emulsion copolymerization of butadiene (75)-styrene (25) is initiated by redox systems containing potassium chromate as oxidizing constituent. In alkaline (soap) recipes, the system chromate-arsenic trioxide is especially effective, giving a rate of conversion of about 20% per hour at 30°C. with 5 parts of potassium myristate (0.3 part of potassium chromate and 0.07 part of arsenic trioxide per 100 parts of monomers). Other fatty acid soaps or sodium alkyl sulfate may be used instead of myristate, although no other soap or emulsifier tested gives a rate as large as does myristate. Mercaptan has a slight accelerating effect but the presence of mercaptan is not necessary for initiation of polymerization. The use of arsenic trisulfide as reducing agent gives rise to rapid polymerization but the rates vary with different suspensions of arsenic trisulfide. Potassium antimonyl tartrate also may be used in combination with chromate to give rapid polymerization at 40°C. with fatty acid soap. Tin(II) is much less effective than either arsenic(III) or antimony(III). Inorganic reducing agents which in combination with chromate are inefficient in initiating the copolymerization include iron(II), thallium(I), dithionite, hydrazine, hydroxylamine, and sulfide.
Additional Material:
1 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/pol.1952.120090405
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