ISSN:
0360-6376
Keywords:
Physics
;
Polymer and Materials Science
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
Diallyl o-phthalate (DAP) has been polymerised by γ-radiation from a 60Co source and the kinetics of polymerization have been studied at several dose rates and temperatures. The results show that the rate of polymerization was proportional to I0.68, where I is the radiation dose rate. The net activation energy of the polymerization reaction (Ep - 1/2Et) was 5.02 kcal/mole, where Ep and Et are the activation energies for the propagation and termination steps, respectively. The radical yield GR for DAP was measured by the loss of diphenyl picryl hydrazyl (DPPH) used as a radical scavenger. GR in the solution after irradiation was 3.12. The ratio of the rate constants kp2/kt was calculated to be 4.09 times; 10-7 at 25.8°C and 15.0 × 10-7 at 55.4°C. At room temperature, the ratio of degradative chain transfer constant to kp, i.e., ku/kp was found to be 0.065 and ktr/ku as 0.032, where ktr is the nondegradative chain-transfer constant. Molecular weights of these polymers as determined by vapor pressure osmometry showed that the degree of polymerization was between 8 and 10. Infrared spectra of the polymers indicated that intramolecular cyclization took place during polymerization.
Additional Material:
9 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/pol.1975.170130203
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