Polymérisation anionique amorcée par les composés lamellaires du graphite et du lithium

Autor: J. P. Pascault, Jean Golé, A. Hérold, Q.T. Pham, I.M. Panayotov, Robert Salle, G. Merle, C. Pillot, Iliya Rashkov, D. Guérard
Rok vydání: 1977
Předmět:
Zdroj: Journal of Polymer Science: Polymer Chemistry Edition. 15:2067-2074
ISSN: 1542-9369
0360-6376
DOI: 10.1002/pol.1977.170150903
Popis: In the present work, we use the binary insertion compound LiC12 to polymerize styrene, methyl methacrylate, butadiene, isoprene, and to copolymerize isoprene and styrene in various hydrocarbon solvents (aromatics and aliphatic) and etheral solvents. We show that the styrene polymerization in aromatic solvents gives better yields than in the etheral solvents, the polymer being atactic. Methyl methacrylate does not polymerize in toluene but does so completely in DME. More generally, the yields of polymerization are better with KC37 than with LiC12 because of the different capacities of the monomer to get into the carbon layers. The polymerization of dienes with LiC12 shows that the microstructures of the polymer obtained in π-or n-donor solvents are similar to the ones obtained by homogenous polymerization with Li cation in such solvents. However, for isoprene in cyclohexane, the results are different. The isoprene styrene copolymers are statistical ones and the mean length of styrene blocks is less than 5. The monomer interaction with the insertion compound and the growing chain geometry between the carbon layers are the facts which control either the stereospecificity of the polymerization or the selectivity of the copolymerization.
Databáze: OpenAIRE
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