ISSN:
0449-296X
Keywords:
Physics
;
Polymer and Materials Science
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
The kinetics of γ-radiation-induced free-radical polymerization of styrene were studied over the temperature range 0-50°C at radiation intensities of 9.5 × 104, 3.1 × 105, 4.0 × 105, and 1.0 × 106 rad/hr. The overall rate of polymerization was found to be proportional to the 0.44-0.49 power of radiation intensity, and the overall activation energy for the radiation-induced free-radical polymerization of styrene was 6.0-6.3 kcal/mole. Values of the kinetic constants, kp2/kt and ktrm/kp, were calculated from the overall polymerization rates and the number-average molecular weights. Gelpermeation chromatography was used to determine the number-average molecular weight M̄n, the weight-average molecular weight M̄w, and the polydispersity ratio M̄w/M̄n, of the product polystyrene. The polydispersity ratios of the radiation-polymerized polystyrene were found to lie between 1.80 and 2.00. Significant differences were observed in the polydispersity ratios of chemically initiated and radiation-induced polystyrenes. The radiation chemical yield, G(styrene), was calculated to be 0.5-0.8.
Additional Material:
15 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/pol.1969.150070715
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