ISSN:
0022-3832
Keywords:
Chemistry
;
Polymer and Materials Science
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
,
Physics
Notes:
The rates of decomposition of benzoyl, lauroyl, bis(p-chlorobenzoyl), and bis(2,4-dichlorobenzoyl) peroxides, 0.0133 molar in styrene, have been determined at 34.8, 49.4, 61.0, 74.8, and 100°C., and the corresponding rates of polymerization of styrene have also been determined. Assuming the initial rate of polymerization of styrene, produced by benzoyl peroxide at an initial concentration of 0.0133 m./l. at each of the five temperatures used to be unity, the relative initial rates of polymerization produced by the peroxides studied are as follows: bis(2,4-dichlorobenzoyl) 2.15, lauroyl 1.52, and bis(p-chlorobenzoyl) 0.87. The rate data have been subjected to an approximate kinetic analysis, from which one may conclude that the order of intrinsic effectiveness of the peroxides as chain-initiating agents in styrene is benzoyl 〉 bis(p-chlorobenzoyl) 〉 lauroyl 〉 bis(2,4-dichlorobenzoyl), and that the effectiveness increases with increasing temperature. The activation energy for the peroxide-initiated polymerization of styrene was found to be 21 kcal. per mole. The molecular weight of polystyrene appears to be an inverse function of the temperature, the polymerization rate, the peroxide decomposition rate, and the extent of wasteful decomposition of the peroxide.
Additional Material:
8 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/pol.1948.120030405
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