Trans-stereospecific polymerization of butadiene and random copolymerization with styrene using borohydrido neodymium-magnesium dialkyl catalystsReportar como inadecuado




Trans-stereospecific polymerization of butadiene and random copolymerization with styrene using borohydrido neodymium-magnesium dialkyl catalysts - Descarga este documento en PDF. Documentación en PDF para descargar gratis. Disponible también para leer online.

1 CIMAP - UMR 6252 - Centre de recherche sur les Ions, les MAtériaux et la Photonique 2 UCCS - Unité de Catalyse et de Chimie du Solide 3 Service Commun de RMN 4 LSEO - Laboratoire de Synthèse et Electrosynthèse Organométalliques

Abstract : The combination of a neodymium borohydride, NdBH43THF3 1 or Cp*NdBH42THFx 2, with MgnBuEt BEM, affords an efficient and highly selective up to 96.7% 1,4-trans catalyst for butadiene polymerization. In the presence of excesses of Mg co-catalyst, polymer chain transfer takes place between neodymium and magnesium, and significant amounts of 1,2-units are observed. When considered for butadiene-styrene statistical copolymerization, the catalytic system based on 2 showed a good ability to produce poly1,4-trans-butadiene-co-styrene, with strong impact of the Mg-Nd ratio on the yield and on the copolymer microstructure, including the percentage of inserted styrene up to 16.9 mol%. Whatever the co-monomers concentration the polybutadiene backbone remained 1,4-trans. The precise microstructure of the polymers and copolymers was thoroughly analyzed by means of high resolution NMR spectroscopy 900 MHz and MALDI-ToF spectrometry.

Keywords : stereospecific polymerization styrene-butadiene copolymer trans-polybutadiene rare earths microstructure NMR





Autor: Aude Ventura - Thomas Chenal - Marc Bria - Fanny Bonnet - Philippe Zinck - Yvette Ngono-Ravache - Emmanuel Balanzat - Marc Vissea

Fuente: https://hal.archives-ouvertes.fr/



DESCARGAR PDF




Documentos relacionados