ISSN:
0022-3832
Keywords:
Chemistry
;
Polymer and Materials Science
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
,
Physics
Notes:
Butadiene-styrene copolymers have been prepared at subfreezing temperatures by means of redox recipes employing inorganic salts as freezing point depressants. Specific salt-emulsifier combinations are required for optimum rates of polymerizations. With a sufficient amount of the inorganic salt to lower the freezing point of water 10°C., the sodium chloride-potassium caprylate combination resulted in a 60% conversion in 4.6 hours, the calcium chloride-sodium hexyl sulfate combination resulted in a 41% conversion in 24 hours, and the calcium chloride-alkyl aryl polyether alcohol combination resulted in a 58% conversion in 18.5 hours.Low molecular weight mercaptans such as tert-butyl mercaptan can be employed as practical modifiers for this recipe.Certain of the physical properties of the salt antifreeze copolymers prepared at -10°C. are superior to those of copolymers prepared at the same temperature by means of conventional recipes. The ease of processing and the heat-aged properties are exceptional. One copolymer after 24 hours of aging at 100°C. withstood 118,000 flexures before a puncture increased to one inch in length at 99°C. The superiority of the product is attributed to the precipitation of the copolymer during the course of the polymerization.
Additional Material:
10 Tab.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/pol.1951.120070206
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