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Investigation of the initiation reaction of isoprene polymerization with 2‐ethylhexylsodium in heptane
Author(s) -
Pakuro Natalia I.,
ArestYakubovich Alexander A.,
Shcheglova Larisa V.
Publication year - 1997
Publication title -
macromolecular chemistry and physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.57
H-Index - 112
eISSN - 1521-3935
pISSN - 1022-1352
DOI - 10.1002/macp.1997.021981207
Subject(s) - isoprene , polymerization , chemistry , heptane , polymer chemistry , induction period , kinetics , anionic addition polymerization , reaction rate constant , order of reaction , organic chemistry , copolymer , polymer , catalysis , physics , quantum mechanics
The kinetics of the initiation of isoprene polymerization in heptane with the hydrocarbon‐soluble alkylsodium compound 2‐ethylhexylsodium was studied. Initiation rates were estimated from the induction period and by measuring UV spectra of polyisoprenyl‐sodium (λ max = 304 nm) during the course of polymerization. The initiation reaction is first order in initiator both in the course of the reaction and with respect to the starting concentration of the initiator. The same result is obtained when 2‐ethylhexyllithium is used. The initiation rate constants are: k i = 1,6 · 10 −3 and 5,5 · 10 −4 L/(mol · s) for sodium and lithium compounds at 26°C, respectively. Aggregated forms of organoalkali compounds are suggested to take part in the initiation reaction of isoprene polymerization.