alpha,omega-Bis(trialkoxysilyl) difunctionalized polycyclooctenes from ruthenium-catalyzed chain-transfer ring-opening metathesis polymerization

Xiaolu Michel (1) , Stéphane Fouquay (2) , Guillaume Michaud (3) , Frédéric Simon (3) , Jean-Michel Brusson (4) , Jean-François Carpentier (1) , Sophie M. Guillaume (1)

1 ISCR - Institut des Sciences Chimiques de Rennes
2 BOSTIK S.A
3 BOSTIK CRD
4 Total Corporate Research

The ring-opening metathesis polymerization/cross-metathesis (ROMP/CM) of cyclooctene (COE) using bis(trialkoxysilyl)alkenes as chain-transfer agents (CTAs) and Ru catalysts to afford difunctionalized polyolefins is reported. The formation of alpha,omega-bis(trialkoxysilyl) telechelic polycycloolefins (DF) with controlled molar mass values takes place quite selectively (>90 wt%), along with minor amounts of cyclic non-functionalized polymers (CNF), as evidenced by NMR, MALDI-ToF MS, SEC analyses and fractionation experiments. The nature of the CTA and catalyst influenced much the efficiency and selectivity of the reaction. (MeO)(3)SiCH2CH=CHCH2Si(OMe)(3) (2) and (MeO)(3)Si(CH2)(3)NHC(O)OCH2CH=CHCH2OC(O)NH (CH2)(3)Si(OMe)(3) (5) proved to be the most efficient CTAs in terms of reactivity, catalyst productivity and selectivity towards DF. Diurethane CTA 5 is easily prepared, and can also be conveniently generated in situ during the ROMP/CM. Grubbs' 2nd-generation catalyst (G2) and Hoveyda-Grubbs's catalyst (HG2) afforded the best compromise in terms of selectivity and productivity, with turnover numbers of up to 95 000 mol(COE) mol(Ru)(-1) and 5000 mol(CTA) mol(Ru)(-1).

Keywords: functional silyl groups; anionic living polymerization; terminated telechelic poly(butadiene)s; free-radical polymerization; aba triblock copolymers; transfer agents; glycerol carbonate; olefin metathesis; monomers; end

Domains: Chemical Sciences; Organic chemistry

Xiaolu Michel, Stéphane Fouquay, Guillaume Michaud, Frédéric Simon, Jean-Michel Brusson, et al.. alpha,omega-Bis(trialkoxysilyl) difunctionalized polycyclooctenes from ruthenium-catalyzed chain-transfer ring-opening metathesis polymerization. Polymer Chemistry, 2016, 7 (29), pp.4810--4823. ⟨10.1039/c6py00849f⟩. ⟨hal-01357417⟩