can lead to the production of unique and well defined polyolefin based materials
exhibiting original properties. ... Vasile, in Handbook of Polyolefins, 2nd ed.
CHIMIE CATALYSE POLYMERES ET PROCEDES (LCPP Team) C2P2 – UMR 5265 CNRS/CPE/UCBL – 43, Bd. Du 11 Novembre 1918 – 69616 VILLEURBANNE Cedex
END FUNCTIONALIZATION OF POLYOLEFIN CHAINS. APPLICATION TO THE DESIGN OF MACROMOLECULAR ARCHITECTURES Polymerization by coordination chemistry is the system of choice for the production of polyolefins which are the most important class of thermoplastics.1 The resulting materials (principally polyethylene (high density (PEHD) and linear low density (LLDPE)), isotactic-polypropylene (i-PP)) exhibit such unique mechanical properties that they remain unavoidable for many applications. In addition to the favourable mechanical properties, the very high productivity related to the catalytic feature of the polymerization system gives to this route an invaluable attractiveness for the industry. Among the catalytic systems used, Ziegler/Natta catalysts are by definition formed by combination of a transition metal complex with a main group organometallic compound. During the growth of the chains, chain transfer reactions such as chain transfer to the organometallic compound can occur (Scheme 1). CH 2 CH R
Met + R ' Met' n
CH 2 CH
Met' + R ' Met n
R
Scheme 1: Chain transfer reaction to a main group organometallic compound (R’-Met’) during olefin coordination polymerization in the presence of a transition metal catalyst (Met).
Indeed, such transfer reactions can for example become advantageously very rapid and/or reversible. When reversible and in absence of another transfer reaction, the polymerization is best described as pseudo living and all the chains are then bound to a metal (Catalyzed Chain Growth or CCG). Recently, the Dow Chemical company was the first to discover2 that the use of such systems can lead to the production of unique and well defined polyolefin based materials exhibiting original properties. Taking advantage of the reactivity of the carbon metal bond, our group found that these systems can indeed be turned into very original functionalization tools for polyethylene chains (Scheme 2).3 The aim of the project is to use the resulting end functionalized polyolefins as building blocks for the design of macromolecular architectures incorporating poly(ethylene oxide) (PEO) segments. The association of a very crystalline and hydrophobic polymer such as PE together with the commercially Scheme 2: General overview of applications of end available hydrophilic PEO is meant to lead to original functionalized polyethylene obtained after CCG on Mg. materials exhibiting unique properties in water or polar media. The project will then take advantage of the strong expertise of the C2P2 group both in (i) the design of polyolefin based macromolecular architectures and (ii) the self-assembly of amphiphilic structures. The work program will include organic chemistry, polymer chemistry and physico-chemistry providing the candidate with a large culture in the field of polymer. Contact: Dr. Muriel Lansalot (
[email protected]), Dr. Christophe Boisson (
[email protected]), Dr. Franck D’Agosto (
[email protected]), Tel: 33 4 72 43 17 70 ou : 33 4 72 43 17 80. www.lcpp-cpe.com 1
C. Vasile, in Handbook of Polyolefins, 2nd ed.(Ed. Marcel Dekker) 2000 (New York). D. J. Arriola, E. M. Carnahan, P. D. Hustad, R. L. Kuhlman, T. T. Wenzel, Science, 2006, 312, 714-719; M. Zintl, B. Rieger, Angew. Chem., Int. Ed., 2007, 46, 333-335; R. L. Kuhlman, T. T. Wenzel, Macromolecules, 2008, 41, 4090-4094. 3 Briquel, R.; Mazzolini, J.; Bris, T. L.; Boyron, O.; Boisson, F.; Delolme, F.; D'Agosto, F.; Boisson, C.; Spitz, R. Angew. Chem. Int. Ed. 2008, 47, 9311-9313. Mazzolini, J.; Espinosa, E.; D'Agosto, F.; Boisson C. Polym. Chem. 2010, 1, 793-800, D'Agosto, F.; Boisson, C. Aust. J. Chem. 2010, 63, 1155-1168. E. Espinosa, M. Glassner, C. Boisson, C. Barner Kowollik, F. D’Agosto Macromol. Rapid Commun. 2011, 32, 1447-1453. M. Unterlass, E. Espinosa, F. Boisson, F. D’Agosto, C. Boisson, K. Ariga, I. Khalakhan, R. Charvet, JP. Hill Chem. Commun. 2011, 47, 7057-7059. 2
