References of "Halleux, Olivier"
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See detailAmphiphilic copolymers of epsilon-caprolactone and gamma-substituted epsilon-caprolactone. Synthesis and functionalization of poly(D,L-lactide) nanoparticles
Gautier, Sandrine; D'Aloia, Violetta; Halleux, Olivier et al

in Journal of Biomaterials Science. Polymer Edition (2003), 14(1), 63-85

Fully biodegradable and surface-functionalized poly(D,L-lactide) (PLA) nanoparticles have been prepared by a co-precipitation technique. Novel amphiphilic random copolyesters P(CL-co-gamma XCL) were ... [more ▼]

Fully biodegradable and surface-functionalized poly(D,L-lactide) (PLA) nanoparticles have been prepared by a co-precipitation technique. Novel amphiphilic random copolyesters P(CL-co-gamma XCL) were synthesized by controlled copolymerization of epsilon-caprolactone and epsilon-caprolactone substituted in the gamma-position by a hydrophilic X group, where X is either a cationic pyridinium (gamma-Py-CL) or a non-ionic hydroxyl (gamma-OH-CL). Nanoparticles were prepared by co-precipitation of PLA with the P(CL-co-gamma-XCL) copolyester from a DMSO solution. Small amounts of cationic P(CL-co-gamma-Py-CL) copolymers are needed to quantitatively form stable nanoparticles (ca. 10 mg/100 mg PLA), although larger amounts of non-ionic P(CL-co-gamma-OH-CL) copolymers are needed (ges12.5 mg/100 mg PLA). Copolymers with a low degree of polymerization (ca. 40) are more efficient stabilizers, probably because of faster migration towards the nanoparticle-water interface. The nanoparticle diameter decreases with the polymer concentration in DMSO, e.g. from ca. 160 nm (16 mg/ml) to ca. 100 nm (2 mg/ml) for PLA/P(CL-co-gamma-Py-CL) nanoparticles. Migration of the P(CL-co-gamma-XCL) copolyesters to the nanoparticle surface was confirmed by measurement of the zeta potential, i.e. ca. +65 mV for P(CL-co-gamma-Py-CL) and -7 mV for P(CL-co-gamma-OH-CL). The polyamphiphilic copolyesters stabilize PLA nanoparticles by electrostatic or steric repulsions, depending on whether they are charged or not. They also impart functionality and reactivity to the surface, which opens up new opportunities for labelling and targeting purposes. [less ▲]

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See detailRing-opening polymerization of epsilon-caprolactone in Supercritical Carbon Dioxide
Stassin, Fabrice; Halleux, Olivier; Jérôme, Robert ULg

in Macromolecules (2001), 34(4), 775-781

The ring-opening polymerization of ε-caprolactone (CL) initiated by dibutyltin dimethoxide was studied in supercritical carbon dioxide at 40 °C, under a pressure of 210−215 bar. The polymerization is ... [more ▼]

The ring-opening polymerization of ε-caprolactone (CL) initiated by dibutyltin dimethoxide was studied in supercritical carbon dioxide at 40 °C, under a pressure of 210−215 bar. The polymerization is controlled as assessed by the linear dependence of Mn,SEC on conversion and of ln([CL]0/[CL]) on time. Moreover, there is a good agreement between Mn,SEC and Mn,calc, at least until 20 000 g/mol. The apparent rate constants of polymerization in different media increase as follows: sc CO2, CFC-113, toluene, bulk. The kinetic order in initiator for the polymerization in solution and in sc CO2 was extracted from the slope of ln kapp vs ln [Sn]0. It appears to depend on the initiator concentration in solution, which is not the case in sc CO2. [less ▲]

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See detailNew Functional Aliphatic Polyesters by Chemical Modification of Copolymers of ε-Caprolactone with γ-(2-Bromo-2-methylpropionate)- ε-caprolactone, γ-Bromo- ε-caprolactone, and a Mixture of β-and γ-Ene- ε-caprolactone
Detrembleur, Christophe ULg; Mazza, Michaël; Lou, Xudong et al

in Macromolecules (2000), 33(17), 7751-7760

New functional aliphatic polyesters were prepared by chemical modification of brominated copolyesters. Poly(epsilon-caprolactone)-co-poly(gamma-(2-bromo-2-methylpropionate)-epsilon-caprolactone) copolymer ... [more ▼]

New functional aliphatic polyesters were prepared by chemical modification of brominated copolyesters. Poly(epsilon-caprolactone)-co-poly(gamma-(2-bromo-2-methylpropionate)-epsilon-caprolactone) copolymer was prepared and successfully converted into copolyester bearing methacrylate double bonds by dehydrohalogenation of the pendant tertiary alkyl bromides, thus leading to cross-linkable polyester. The tertiary alkyl bromide groups of the original copolyester were also quaternized by reaction with pyridine, although some side reactions occurred which Limited the reaction yield. Nevertheless, quaternization of the bromide groups of the poly(epsilon-caprolactone)-co-poly(gamma-bromo-epsilon-caprolactone) copolymer proved to be quantitative and to occur without degradation of the polyester chains. This general strategy paves the way to either amphiphilic copolyesters or water-soluble polyesters. The poly(epsilon -caprolactone)-co-poly(gamma -bromo-epsilon-caprolactone) lactone) copolymer was also quantitatively converted into unsaturated copolyester by dehydrohalogenation with formation of double bonds including acrylic-type double bonds. As an alternative, gamma-bromo-epsilon-caprolactone was first dehydrohalogenated, and the unsaturated cyclic monomer was copolymerized with epsilon-caprolactone. Finally, the nonconjugated double bonds of the copolyesters were oxidized into epoxides, except for the acrylic-type unsaturations which remained unchanged. [less ▲]

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See detailSynthesis of new hydrophilic γ-substituted poly-ε-caprolactones
Lecomte, Philippe ULg; D'aloia, Violetta; Mazza, Michaël et al

Conference (2000, August 20)

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See detailγ-bromo-ε-caprolactone, a versatile lactone for the synthesis of new functional aliphatic polyesters
D'Aloia, Violetta; Gautier, Sandrine; Halleux, Olivier et al

Poster (2000, May 02)

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See detailRing opening copolymerization of ε-caprolactone, γ-(triethylsilyloxy)-ε-caprolactone and γ-ethylene ketal-ε-caprolactonelactone: a route to hetero-graft copolyesters
Stassin, Fabrice; Halleux, Olivier; Dubois, Philippe ULg et al

in Macromolecular Symposia (2000), 153

ε-Caprolactone (ε-CL) has been copolymerized with two precursors of γ-hydroxy-ε-CL, i.e., γ-ethylene ketal-ε-caprolactone (TOSUO) and γ-(triethylsilyloxy)-ε-caprolactone (TeSCL). The triethylsilyloxy ... [more ▼]

ε-Caprolactone (ε-CL) has been copolymerized with two precursors of γ-hydroxy-ε-CL, i.e., γ-ethylene ketal-ε-caprolactone (TOSUO) and γ-(triethylsilyloxy)-ε-caprolactone (TeSCL). The triethylsilyloxy pendant groups can be selectively deprotected into hydroxyl groups followed by the deprotection of the acetal substituents. Each series of hydroxyl groups can be used to initiate the polymerization of cyclic monomers so leading to hetero-graft copolyesters with, for instance, poly-ε-CL and polylactide grafts. [less ▲]

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See detailRing-Opening Polymerization of γ-bromo-ε-caprolactone : A novel route to functionalized aliphatic polyesters
Detrembleur, Christophe ULg; Mazza, Michaël; Halleux, Olivier et al

in Macromolecules (2000), 33(1), 14-18

The synthesis, characterization, and polymerization of a new cyclic ester, gamma-bromo-epsilon-caprolactone (gamma-BrCL), are reported. The ring-opening polymerization (ROP) of this new monomer initiated ... [more ▼]

The synthesis, characterization, and polymerization of a new cyclic ester, gamma-bromo-epsilon-caprolactone (gamma-BrCL), are reported. The ring-opening polymerization (ROP) of this new monomer initiated from Al((OPr)-Pr-i)(3) as initiator in toluene at 0 degrees C was found to be living and proceeds by a coordination-insertion mechanism. Random and block copolymerizations of this gamma-BrCL with epsilon-caprolactone (epsilon-CL) were also found to be living as evidenced by the experimental molecular weight which is consistent with that expected from the monomer to initiator molar ratio, the narrow polydispersity, and the good agreement between the comonomers molar fraction in the comonomer feed and the copolymer. The thermal transitions (Tg and Tm) in the epsilon-CL/gamma-Br-CL random copolymers depend strongly on the gamma-BrCL content. Increasing the gamma BrCL content in the copolymer [F(BrCL)] increased the Tg of the copolymer from -61 degrees C for poly(epsilon-caprolactone) to -16.5 degrees C for the poly( gamma-BrCL) homopolymer but decreased the Tm of the PCL to contents of similar to 30 mol % of gamma BrCL [F(BrCL) =0.3]Beyond this value, the copolymers were found to be amorphous and exist as viscous liquids. [less ▲]

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See detailSynthesis of new hydrophilic γ-substituted poly(ε-caprolactone)s
Lecomte, Philippe ULg; D'aloia, Violetta; Mazza, Michaël et al

in Polymer Preprints (2000), 41(2), 1534-1535

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See detailNovel functionalization routes of poly(ε-caprolactone)
Lecomte, Philippe ULg; Detrembleur, Christophe ULg; Lou, Xudong et al

in Macromolecular Symposia (2000), 157

The aluminum alkoxide mediated ring opening polymerization of functional lactones, such as γ-ethylene ketal-ε-caprolactone (TOSUO), γ-(triethylsilyloxy)-ε-caprolactone (SCL) and γ-bromo-ε-caprolactone ... [more ▼]

The aluminum alkoxide mediated ring opening polymerization of functional lactones, such as γ-ethylene ketal-ε-caprolactone (TOSUO), γ-(triethylsilyloxy)-ε-caprolactone (SCL) and γ-bromo-ε-caprolactone (γBrCL), is a versatile route to polyesters containing ketal, ketone, alcohol and bromide groups. As result of living polyaddition mechanism, random and block copolymerization of εCL and γBrCL has been successfully carried out. The reactivity ratios are quite similar (1.08 for ε-CL, and 1.12 for γBrCL). These random copolymers are semicrystalline when they contain less than 30 mol% of γBrCL, otherwise they are amorphous. No transesterification reaction occurs during the sequential polymerization of ε-CL and γBrCL leading to block copolymers. Reaction of poly(εCL-co-γBrCL) with pyridine provides quantitatively a polycationic polyester. Furthermore, the reaction of this random copolymer with l,8-diazabicyclo[5.4.0] undec-7-ene (DBU) is a route to unsaturated polyesters, whose the non conjugated double bonds can be quantitatively converted into epoxides by reaction with m-chloroperbenzoic acid (mCPBA). No chain degradation is detected during these derivatization reactions of poly (εCL-co-γBrCL). [less ▲]

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See detailPoly(2-oxepane-1,5-dione) : a highly crystalline modified poly (epsilon-caprolactone) of a high melting temperature
Tian, Dong; Halleux, Olivier; Dubois, Philippe ULg et al

in Macromolecules (1998), 31(3), 924-927

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