Research Group Leader : Pr Olivier Coulembier

Phone :+32(0)

Secretariat : +32(0)

The interest of our research is mainly focused on the preparation of (biocompatible/biodegradable) polymers presenting complex architectures. Specific initiators, living/controlled polymerization procedures, quantitative organic transformations and new monomers are prepared in our group and used for the construction of complex materials including cyclic, star-shaped, dendrimer-like star or hyperbranched architectures. For the sake of greening the chemistry, our approach relies on a biomimetic inspiration from Nature. By corollary, the activation of carbon dioxide to enable its use as a synthon or a participating polymerization molecule is arousing our interest.”

Projects :

  • SOLIDYE (EU, Région wallonne)
  • BIORGEL (EU, Région wallonne)
  • BATWAL : Région wallonne
  • HYB2HYB : Région wallonne

Top selected papers

Reinvestigation of the Mechanism of Polymerization of b – Butyrolactone from 1,5,7-Triazabicyclo[4.4.0]dec-5-ene.

Abstract The questionable mechanism initially proposed to explain how the 1,5,7-triazabicyclo[4.4.0]dec-5ene (TBD) allows to ring-open b-lactones, such as b-butyrolactone (BL), is here reinvestigated. Thanks to the use of a trisubstituted b-lactone, i.e. (R,S)-benzylcarbonyl-3,3-dimethyl-2-oxetanone,  and the association of techniques such as 1H/DOSY NMR and MALDI/ESI-MS, we demonstrated that BL is effectively polymerized by the TBD in bulk at 60°C, minorly from the reported N-acyl-a,b-unsaturated TBD species, and majorly from crotonate anions issued from the basic activation of BL. On the contrary to what has been reported, the TBD is not covalently linked to the PBL chain but mainly plays the role of
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Influence of chain topology (cyclic versus linear) on the nucleation and isothermal crystallization of poly(L-lactide) and poly(D-lactide).

Abstract In this paper, ring closure click chemistry methods have been used to produce cyclic c-PLLA and c-PDLA of a number average molecular weight close to 10 kg/mol. Linear precursors (before ring closure) with similar molecular weights were employed for comparison purposes. The effects of stereochemistry of the polymer chains and their topology on their structure, nucleation and crystallization were studied in detail employing Wide Angle X-ray Scattering (WAXS), Small Angle X-ray Scattering (SAXS), Polarized Light Optical Microscopy (PLOM) and standard and advanced Differential Scanning Calorimetry (DSC).   More information
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Isotactic Degradable Polyesters derived from O-Carboxyanhydrides of L-lactic and L-malic acid using a Single Organocatalyst/Initiator System

Abstract The preparation of stereoregular isotactic P(L-BnMA) and PLLA by ring-opening polymerization (ROP) of 5-(S)-[(benzyloxycarbonyl)methyl]-1,3-dioxolane-2,4-dione (L-malOCA) and (S)-5-methyl-1,3-dioxolane-2,4-dione (L-lacOCA) is reported. The polymerization process was shown to be well controlled using two easily accessible single organocatalyst/initiator systems, pyridine/Lbenzyl(Bn)malate and pyridine/lactic acid (Py·LA) ion pair adducts respectively. The obtained biodegradable polymers displayed narrow dispersity (ĐM) and excellent molar mass control. All ROP reactions were conducted at ambient temperature. The stereoregularity and thermal properties of the materials were thoroughly studied, demonstrating the retention of high levels of isotactic enrichment.   More information
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Cyclic Polymers by the Ring-Closure Strategy: an Updated Review

Abstract The preparation of cyclic macromolecules has always represented a challenging task in polymer science mainly due to difficulties in connecting chain extremities together. Initiated with the pioneering works of Jacobson and Stockmayer, preparative pathways to cyclic polymers have been considerably improved within the last two decades thanks to the advent of both controlled polymerization mechanisms and efficient coupling reactions in organic chemistry. This review aims at providing a critical up-to-date overview and illustration of the considerable efforts that have been furnished in the past few years to improve the availability of macrocycles for industrial and academia investigations by means of
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Synthesis and characterization of double crystalline cyclic diblock copolymers of poly(e-caprolactone) and poly(L(D)-lactide) (c(PCL-b- PL(D)LA)).

Abstract The synthesis of symmetric cyclo poly(ε-caprolactone)–block–poly(L(D)-lactide) (c(PCL–b–PL(D)LA)) by combining ROP of ε-caprolactone and lactides and subsequent click chemistry reaction of the linear precursors containing antagonist functionalities is presented. The two blocks can sequentially crystallize and self-assemble into double crystalline spherulitic superstructures. The cyclic chain topology significantly affects both the nucleation and the crystallization of each constituent, as gathered from a comparison of the behavior of linear precursors and cyclic block copolymers. The stereochemistry of the PLA block does not have a significant effect on the non-isothermal crystallization of both linear and cyclo PCL-b-PDLA and PCL-b-PLLA copolymers.  More information
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