Initiation of Retarded Styrene Anionic Polymerization Using Complexes of Lithium Hydride with Organometallic Compounds

• Published in: Macromolecules Vol. 36; no. 16; pp. 5988 - 5994
• Main Authors: Ménoret, Stéphane, Deffieux, Alain, Desbois, Philippe
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 12.08.2003
• Subjects: Applied sciences; Exact sciences and technology; Organic polymers; Physicochemistry of polymers; Polymerization; Preparation, kinetics, thermodynamics, mechanism and catalysts; One pot reaction; Styryl polymer; Breakdown initiation; Hydrogen; Hydrogenolysis; In situ; Priming activity; Magnesium Organic compounds; Experimental study; Solution polymerization; Chain transfer; Anionic catalyst; Reaction mechanism; Anionic polymerization; Styrene polymer; Aluminium Organic compounds; Chemical synthesis; Lithium hydride
• ISSN: 0024-9297; 1520-5835
• DOI: 10.1021/ma034256b

The hydrogenolysis of poly(styryllithium) species leads to the in situ formation of lithium hydride, which is able to reinitiate styrene anionic polymerization at 100 °C. However, the slow addition rate of LiH to styrene with respect to propagation yields incomplete initiation. The presence of an organometallic derivative such as dibutylmagnesium or triisobutylaluminum was found to improve both the solubility and the reinitiation efficiency of lithium hydride. This behavior is explained by the formation of bimetallic complexes which slow down the propagation and favor the initiation. Following these findings, the use of hydrogen as chain transfer agent in the anionic retarded polymerization of styrene was investigated.