ISSN:
0449-296X
Schlagwort(e):
Physics
;
Polymer and Materials Science
Quelle:
Wiley InterScience Backfile Collection 1832-2000
Thema:
Chemie und Pharmazie
Notizen:
It was found that the metallation of diene polymers with n-butyllithium in n-heptane takes place in the presence of a tert amine, i.e. N,N,N′,N′-tetramethylethylenediamine. Butyllithium was added to the diene polymer in n-heptane in the presence of an equimolar amount of the amine, and the mixture was allowed to react at 80°C. for 60 min. under nitrogen. As a result, 27% and 9% per monomer unit for polybutadiene and polyisoprene, respectively, were metallated. The effects of the concentrations of the diene polymer, butyllithium, and the amine on the reaction were studied at 80°C., and the reaction mechanism was discussed. The overall rate of metalation was proportional to the diene polymer concentration and to the square root of the butyllithium concentration. The overall activation energies of metalation were 6.6 and 8.4 kcal./mole for polybutadiene and polyisoprene, respectively. Many kinds of polymer derivative were obtained by treating the metalated polymers with various reagents, such as carbon dioxide, Michler's ketone, trimethylchlorosilane, triphenylchlorosilane, benzaldehyde, and pyridine.
Zusätzliches Material:
12 Ill.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1002/pol.1968.150060312
Permalink
