ISSN:
0098-1273
Schlagwort(e):
Physics
;
Polymer and Materials Science
Quelle:
Wiley InterScience Backfile Collection 1832-2000
Thema:
Chemie und Pharmazie
,
Physik
Notizen:
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.
Zusätzliches Material:
4 Ill.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1002/pol.1974.180120613
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