ISSN:
0098-1273
Keywords:
Physics
;
Polymer and Materials Science
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
,
Physics
Notes:
The kinetics of the disappearance of propagating butadiene radicals produced in the grafting of butadiene to poly(vinyl chloride) was followed by electron spin resonance measurements. The radical species observed in the temperature range 213-298°K is the conjugated allylic radical: \documentclass{article}\pagestyle{empty}\begin{document}$$ \hbox{---} {\rm CH}_{2}\hbox{---}\rm{CH}\hbox{=\hskip-1pt=}{\rm CH}\hbox{---}{\rm CH}_2 \rightleftharpoons\hbox{---}{\rm CH}_2\hbox{---}{\rm CH}\hbox{---}{\rm CH}\hbox{=\hskip-1pt=}{\rm CH}_2 $$\end{document} The reaction conditions were adjusted to provide a highly viscous medium in which the propagation reaction took place. Under these conditions the radicals were stabilized and a precise ESR spectrum was obtained. Arrhenius plots of the second-order decay rate constants yield an activation energy of 5 kcal/mole. This suggests that the bimolecular termination reaction is controlled by the segmental motion of the grafted side chains.
Additional Material:
4 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/pol.1974.180120613
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