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Polymérisation anionique de l'acroléine, 2. Influence de la nature du contre-ion et de la température sur la cinétique de la réaction by Gulino, Danièle ;Golé, Jean ;Pascault, Jean Pierre is a Chemistry article available to read on EtoBox.

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In tetrahydrofuran, with Na' and Li+ as counter-ions, the kinetic order of the anionic polymerization of acrolein is unity for monomer and for initiator. These results indicate that the living ends are not associated at the studied concentrations of initiator. The polymerization rate depends on the nature of the counter-ion. Transfer reactionst0 monomer do not affect the polymerkation rate but greatly change the molecular weights M,, of polyacroleins. The experimental M,, are much lower than the theoretical M,,. The propagationconstants k,, and the transfer constant h, are determined using these experimental values of M,,. From these results, we can conclude that with Li' as counter ion, transfer reactions are much more numerous than with Na+ . Furthermore, the polymerization rate increases with temperature. The activation energies of the propagation and transfer reactions (Ea,J can be determined separately. When the temperature increases the propagation reaction is promoted in comparison to the transfer reaction to monomer, and simultaneously transfer reactions to polymer take place. This last phenomenon restricts the upper value of the polymerization temperature.

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Author

Gulino, Danièle ;Golé, Jean ;Pascault, Jean Pierre

Publisher

Wiley (John Wiley & Sons); Wiley (ISSN 0025-116X)

Published

1981

Language

FR

Field

Chemistry (Physical Sciences)