358 Synthesis and Conformational Study in Good Solvent of An Asymmetric Polysiloxanes Series

Friday, November 6, 2009
Mezzanine (Camino Real Hotel)
Javier Vallejo Montesinos , Department of Chemistry, University of Guanajuato, Guanajuato, Mexico
Eulalia Ramirez Oliva , Department of Chemistry, University of Guanajuato, Irapuato, Mexico
Jorge Armando Cervantes Jáuregui , Department of Chemistry, University of Guanajuato, Irapuato, Mexico
José Antonio Villegas Gasca , Department of Chemistry, University of Guanajuato, Irapuato, Mexico
Previous conformational studies done on asymmetrical low molecular weight polysiloxanes containing a bulky alkyl side group revealed some difficulties when the conformational parameters are related to the thermodynamic properties, in particular with the second virial coefficient value [1] . In order to solve such inconsistencies, it is necessary to study systems composed of a series of high molecular weight asymmetrical polysiloxanes which have a bulky alkyl side group (hexyl-decyl) in order to have a complete conformational study to obtain a more accurate relationship between their conformational parameters as their radius of gyration with their thermodynamic properties as their second virial coefficient. In this work we pretend to show our progress in the synthesis of these polysiloxanes. Similar polysiloxanes have been synthesized before by kinetically controlled cationic ring opening polymerization [2] with successful results making this synthesis route an excellent option to obtain this kind of polysiloxanes useful for the conformational studies. [1]J.A. VILLEGAS AND J. CERVANTES, REVISTA MEXICANA DE FISICA 52 (6) 507_514 DICIEMBRE 2006. [2]QIONGHUA SHEN AND LEONARD V. INTERRANTE, MACROMOLECULES 1997, 30, 5485-5489