ISSN:
0449-296X
Keywords:
Physics
;
Polymer and Materials Science
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
The radiation-induced copolymerization of ethylene and sulfur dioxide has been studied in the liquid and gas phases. In the liquid phase, the copolymer composition remained equimolar over a temperature range of 20-160°C. and ethylene pressures of 50-680 atm. The rate of copolymerization in the liquid phase at 680 atm. increased with temperature to a maximum value at ∼80°C. Above this temperature the rate steadily decreased to zero at 157°C. because of temperature-dependent depropagation reactions. In the gas phase, copolymers were formed that contained from 9 to 46 mole-% sulfur dioxide. Under constant conditions of temperature, pressure, and radiation intensity, the copolymerization rate in the gas phase increased with increasing sulfur dioxide in the initial gas mixture. The propagating species for the liquid-phase experiments is considered to consist of an equimolar complex molecule of ethylene and sulfur dioxide. For gas mixtures containing an excess molar concentration of ethylene, the propagating species are ethylene and the complex molecule. Infrared spectra show polysulfone structures. Calorimetric and x-ray diffraction analyses indicate crystalline structures for copolymers in the range 9-50 mole-% sulfur dioxide, although a melt transition temperature could not be observed for copolymer containing 〉31 mole-% sulfur dioxide. Clear uniform film was obtained with copolymers containing up to 31 mole-% SO2.
Additional Material:
9 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/pol.1968.150061201
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