Reinvestigation of the mechanism of polymerization of ss-butyrolactone from 1,5,7-triazabicyclo[4.4.0]dec-5-ene

S. Moins (1) , C. Henoumont (1) , J. de Winter (1) , A. Khalil (1, 2) , S. Laurent (1, 3) , S. Cammas-Marion (2) , O. Coulembier (1)

1 UMONS - University of Mons [Belgium]
2 ISCR - Institut des Sciences Chimiques de Rennes
3 CMMI

The questionable mechanism initially proposed to explain how 1,5,7-triazabicyclo[4.4.0]dec-5-ene (TBD) allows us to ring-open ss-lactones, such as ss-butyrolactone (BL), is reinvestigated here. With the use of a trisubstituted ss-lactone, i.e. (R,S)-benzylcarbonyl-3,3-dimethyl-2-oxetanone, and the association of techniques such as H-1/DOSY NMR and MALDI/ESI-MS, we demonstrated that BL is effectively polymerized by the TBD in bulk at 60 degrees C, minorly from the reported N-acyl-alpha,ss-unsaturated TBD species, and majorly from crotonate anions issued from the basic activation of BL. In contrast to what has been reported, the TBD is not covalently linked to the PBL chain but mainly plays the role of a counterion in the -C(O) O-, TBDH+ active site.

Domaines: Chimie

S. Moins, C. Henoumont, J. de Winter, A. Khalil, S. Laurent, et al.. Reinvestigation of the mechanism of polymerization of ss-butyrolactone from 1,5,7-triazabicyclo[4.4.0]dec-5-ene. Polymer Chemistry, 2018, 9 (14), pp.1840-1847. ⟨10.1039/c8py00206a⟩. ⟨hal-01771095⟩