Solvent‐Free Ring‐Opening Metathesis Polymerization of Norbornene over Silica‐Supported Tungsten–Oxo Perhydrocarbyl Catalysts. Issue 22 (12th September 2016)

• Record Type: Journal Article
• Authors: Larabi, Cherif; Szeto, Kai C.; Bouhoute, Yassine; Charlin, Marc O.; Merle, Nicolas; Mallmann, Aimery De; Gauvin, Regis M.; Delevoye, Laurent; Taoufik, Mostafa
• Is Part Of: Macromolecular rapid communications. Volume 37:Issue 22(2016)
• Page Start: 1832
• Page End: 1836
• Publication Date: 2016-09-12
• Subjects: heterogeneous catalysis -- metathesis -- norbornene -- polymerization -- tungsten–oxo complexes; Macromolecules -- Periodicals; Polymers -- Periodicals; Chemistry -- Periodicals; 547.705
• DOI: 10.1002/marc.201600419
• Languages: English
• ISSNs: 1022-1336

Abstract

Abstract : Ring opening metathesis polymerization (ROMP) of bicyclo[2.2.1]hept‐2‐ene (norbornene) is carried out over silica‐supported catalysts based on tungsten complexes bearing an oxo ligand (1 : [(SiO)W(O)(CH2 SiMe3 )3, 2 : [(SiO)W(O)(CHCMe2 Ph)(dAdPO)], dAdPO  2, 6 diadamantyl‐4‐methylphenoxide, 3 : [(SiO)2 W(O)(CH2 SiMe3 )2 ]). The evaluation of the catalytic activities of the aforementioned materials in ROMP indicates that at low reaction time (0.5 min), the highest polymer yield is obtained with catalyst2 . However, for longer reaction time (>2 min), complex3, a model of the industrial catalyst, exhibits a better monomer conversion. The polymers obtained are characterized. Moreover, these catalysts are shown to be rather preferentially selective to give the cis polynorbornene (>65%), characterized by high melting points (≈300 °C). The experimental values of the average molecular weight (M n ) of polynorbornenes are found to be close to the theoretical ones for the polymers prepared using catalyst2 and higher for those originated from catalyst3 . Abstract : Catalytic activities of well‐defined silica‐supported tungsten–oxo complexes, prepared via surface organometallic chemistry, are evaluated in ring opening metathesis polymerization of norbornene. [(SiO)2 W(O)(CH2 SiMe3 )2 ], a model of the industrial catalyst, shows the best catalytic performances. Its activity is five times higher compared to the one measured in the presence of toluene. In addition, this material leads to a better control of the polydispersity.