Collect. Czech. Chem. Commun. 2000, 65, 352-360

Effect of Lithium tert-Alkoxides on Anionic Polymerization of Butadiene Initiated with a Bifunctional Initiator

Luděk Tomana, Petr Vlčeka,*, Miloslav Sufčákb, Alexander Pleskab, Jiří Spěváčeka and Petr Hollera

a Institute of Macromolecular Chemistry, Academy of Sciences of the Czech Republic, Heyrovského nám. 2, 162 06 Prague 6, Czech Republic
b Synthetic Rubber Research Institute, Kaučuk, Inc., 278 52 Kralupy nad Vltavou, Czech Republic


Polymerization of buta-1,3-diene initiated by bifunctional dilithium initiator in tert-butyl methyl ether, hexane and hexane-toluene mixtures was studied in the presence of Li tert-butoxide, 2-methylpentan-2-olate, 3-methylpentan-3-olate or 2,3-dimethylbutan-2-olate. The alkoxides lower the overall polymerization rate and affect, to a certain extent, microstructure of formed polymers. When applied in a concentration equal to that of the initiating centres, they lower the content of vinyl structures in polybutadiene by 10-12%. Increasing concentration of the alkoxide has no perceptible effect and, if used in 12-fold excess over the initiator, the content of 1,2-structures even increases. Polymers prepared in the presence of an alkoxide mostly have unimodal and narrow MWDs.

Keywords: Anionic polymerization; Polybutadiene; tert-Alkoxides; Microstructure; Polymers.

References: 40 live references.