References of "Lecomte, Philippe"
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See detailSynthesis of new substituted poly(ε-caprolactone)s by comination of ring-opening polymerization, atom transfer radical addition and click reaction
Lecomte, Philippe ULg; Riva, Raphaël ULg; Schmeits, Stephanie ULg et al

Poster (2005, May 19)

During the last few years, a great research effort has been devoted to the synthesis of aliphatic polyesters, e.g. poly(ε-caprolactone) and polylactides. Indeed, their remarkable properties of ... [more ▼]

During the last few years, a great research effort has been devoted to the synthesis of aliphatic polyesters, e.g. poly(ε-caprolactone) and polylactides. Indeed, their remarkable properties of biodegradability and biocompatibility pave the way to many new applications in the biomedical field and as substitutes for non degradable polymers. In order to tailor the polyester properties, the grafting of functional groups along the polymer backbone is highly desirable. For the last few years, CERM has reported on the synthesis and the (co)polymerization of novel ε-caprolactones γ-substituted by various functional groups, e.g., ketal, ketone, olefin, protected alcohol and carboxylic acid. Nevertheless, the grafting of a specific functional group onto the aliphatic polyester backbone requires the synthesis of the parent substituted ε-caprolactone. There is accordingly a need for a strategy that would use a unique substituted ε-caprolactone, followed by derivatization by well-established reactions, so making available a wide range of pendent functional groups, polymeric or not. The derivatization reactions have however to be quantitative under mild conditions to prevent the aliphatic polyester from degrading. Moreover, these reactions must be compatible with the functional groups of interest, e.g., hydroxyl and carboxylic acid, in order to avoid the use of cumbersome protection/deprotection reactions. This communication aims at reporting that a-chloro-e caprolactone (αCLεCL) can be easily copolymerized with εCL into poly(αCLεCL-co-εCL) copolymers, which are precursors for various aliphatic polyesters, by using either Atom Transfer Radical Addition (ATRA) or Click reactions. The number of steps is limited whatever the "Click" or the "ATRA" strategy under consideration. In both cases, mild conditions have been found, such that degradation is minimized. Pendent hydroxyl, carboxylic acid and epoxide groups have been attached without using any protection/deprotection reaction. This strategy has been implemented for the synthesis of amphiphilic poly(εCL-g-ethylene oxide) graft copolymers, that have been used to prepare poly(D,L-lactide) nanoparticles for drug delivery applications. [less ▲]

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See detailNew developments in the synthesis of aliphatic polyesters by ring-opening polymerisation
Jérôme, Robert ULg; Lecomte, Philippe ULg

in Smith, R. (Ed.) Biodegradable polymers for polymer industrial applications (2005)

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See detailPreparation, characterization and in vitro release properties of ibuprofen-loaded microspheres based on polylactide, poly(epsilon-caprolactone) and their copolymers
Zhu, K. J.; Li, Y.; Jiang, H. L. et al

in Journal of Microencapsulation (2005), 22(1), 25-36

In this paper, ibuprofen was encapsulated into microspheres by oil-in-water (o/w) emulsion solvent evaporation method. Biodegradable polymers with certain compositions and characteristics such as ... [more ▼]

In this paper, ibuprofen was encapsulated into microspheres by oil-in-water (o/w) emulsion solvent evaporation method. Biodegradable polymers with certain compositions and characteristics such as polylactide (PLA), poly(epsilon-caprolactone) (PCL) and their block copolymer were used to prepare the microspheres. The results indicate that, under the same processing conditions, the drug entrapment efficiency was similar (similar to 80%) for microspheres prepared with PLA and P(LA-b-CL) (78.7/21.3 by mole), but it was only 25.4% for PCL microspheres. The in vitro drug release rate decreased in the order of PCL, P(LA-b-CL) (78.7/21.3 by mole) and PLA microspheres. PCL microspheres showed more serious burst release during the first day (almost 80%) than P(LA-b-CL) (50%) and PLA microspheres (18%). The complete ibuprofen release duration from the last two kinds of microspheres exceeded I month. Characterization of the microspheres by differential scanning calorimetry (DSC), scanning electron microscopy (SEM) and polarized optical microscope (POM) revealed that ibuprofen was amorphous in PCL microspheres and partially crystalline in P(LA-h-CL) and PI-A microspheres. The different release behaviour of ibuprofen from the three kinds of microspheres could be attributed to the different crystallinity of the studied polymers and drug dispersion state in polymer matrices. All the above results suggest that the copolymer with a certain ratio of lactide to epsilon-caprolactone could have potential applications for long-term ibuprofen release. [less ▲]

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See detailVersatile functionalization and grafting of poly(epsilon-caprolactone) by Michael-type addition
Rieger, Jutta ULg; Van Butsele, Kathy ULg; Lecomte, Philippe ULg et al

in Chemical Communications (2005), (2), 274-276

The Michael-type addition of aliphatic (co)polyesters onto gamma-acryloyloxy epsilon-caprolactone units is a very straightforward technique of functionalization and grafting, which is tolerant to a ... [more ▼]

The Michael-type addition of aliphatic (co)polyesters onto gamma-acryloyloxy epsilon-caprolactone units is a very straightforward technique of functionalization and grafting, which is tolerant to a variety of functional groups and does not require intermediate protection/deprotection steps. [less ▲]

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See detailComparison of Sm complexes with Sn compounds for syntheses of copolymers composed of lactide and cyclic carbonates and their biodegradabilities
Nakayama, Yuushou; Yasuda, Hajime; Yamamoto, Katsuhiro et al

in Reactive & Functional Polymers (2005), 63(2), 95-105

The comparison of organolanthanide complexes, (C5Me5)(2)SmMe(THF) (Sm1) and [(C5Me5)(2)SM](2)(PhC=C=C=CPh) (Sm2), with tin compounds, Bu2Sn(OMe), (Sn1) and Bu2Sn(OCH2CH2CH2O) (Sn2), in the preparation of ... [more ▼]

The comparison of organolanthanide complexes, (C5Me5)(2)SmMe(THF) (Sm1) and [(C5Me5)(2)SM](2)(PhC=C=C=CPh) (Sm2), with tin compounds, Bu2Sn(OMe), (Sn1) and Bu2Sn(OCH2CH2CH2O) (Sn2), in the preparation of random, diblock, and triblock copolymers composed Of L-lactide (L-LA) or D,L-LA and cyclic carbonates, trimethylene carbonate (TMC) or 2,2-dimethyltrimethylene carbonate (DTC) is reported. The biodegradabilities of the resulting copolymers with proteinase K and a compost were examined. The copolymerization of L-LA with cyclic carbonates by Sm1 or Sm2 afforded copolymers with relatively low melting points (< 160 degrees C) due to the accompanying epimerization in comparison with those obtained with Su1 or Sn2. In the degradation of the polymers with a compost, the copolymers based on D, L-LA were more degradable than those based on L-LA. On the other hand, the effect of the incorporated cyclic carbonate on its degradability was more drastic in the copolymers based on L-LA than those in the copolymers based on D, L-LA. The introduction of only a small amount of the cyclic carbonates into PLLA significantly enhanced the degradability of PLLA with a compost or proteinase K. In the enzymatic degradation of L-LA-containing polymers, the copolymerization of L-LA with TMC was also quite effective to improve the degradability of PLLA. Triblock copolymerization tends to be effective to enhance the degradability of PLLA. [less ▲]

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See detailComparison of Sm complexes with Sn compounds for syntheses of copolymers composed of lactide and cyclic carbonates and their biodegradabilities
Yasuda, Hajime; Yamamoto, Katsuhiro; Nakayama, Yuushou et al

in Reactive & Functional Polymers (2004), 61

The comparison of organolanthanide complexes, (C5Me5)(2)SmMe(THF) (Sm1) and [(C5Me5)(2)SM](2)(PhC=C= C=CPh) (Sm2), with tin compounds, Bu2Sn(OMe)(2) (Sn1) and Bu2Sn(OCH2CH2CH2O) (Sn2), in the preparation ... [more ▼]

The comparison of organolanthanide complexes, (C5Me5)(2)SmMe(THF) (Sm1) and [(C5Me5)(2)SM](2)(PhC=C= C=CPh) (Sm2), with tin compounds, Bu2Sn(OMe)(2) (Sn1) and Bu2Sn(OCH2CH2CH2O) (Sn2), in the preparation of random and diblock copolymers composed Of L-lactide (L-LA) or D,L-LA and epsilon-caprolactone (CL), and the preparation of triblock copolymers composed Of L-LA/CL/L-LA was studied and the biodegradabilities of the resulting copolymers with proteinase K and a compost were examined. Poly(L-LA-ran-CL) shows much higher degradability than poly(L-LA) with proteinase K, and poly(L-LA), poly(L-LA-ran-CL) and poly(L-LA-b-CL) (b means block) prepared with Sm1 had better degradability than those synthesized with the Sn1 compound. The degradability Of Poly(L-LA-ran-CL) with proteinase K is higher than that Of poly(L-LA-b-CL). Poly(LA-ran-CL) and poly(LA-b-CL) prepared with Sml revealed higher degradability than those obtained with Sn1 using a compost. Triblock copolymers, poly(L-LA-b-CL-b-L-LA), synthesized with Sm2 revealed nearly the same degradability with those obtained with Sn2 using a compost. Finally, biocompatibility was studied with macrophage activation assay using RAW 264.7, and metabolic viability assay using Cell Titer Aqueous non-radioactive Cell. [less ▲]

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See detailRecent developments in the ring-opening polymerization of epsilon-caprolactone and derivatives initiated by tin(IV) alkoxides
Lecomte, Philippe ULg; Stassin, Fabrice; Jérôme, Robert ULg

in Macromolecular Symposia (2004), 215

The macromolecular engineering of aliphatic polyesters by Ring-Opening Polymerization (ROP) initiated by aluminum alkoxides is now well established. Tin (IV) alkoxides are less popular, mainly because of ... [more ▼]

The macromolecular engineering of aliphatic polyesters by Ring-Opening Polymerization (ROP) initiated by aluminum alkoxides is now well established. Tin (IV) alkoxides are less popular, mainly because of a poorer control of the chain growth. This paper discusses some recent examples from CERM, showing that tin (IV) alkoxides can advantageously replace the aluminum counterparts as ROP initiators. For instance, they can initiate successfully the Ring-Opening Polymerization of α-chloro-ε-caprolactone and dioxepane-2-one. They are also very promising initiators for ROP in supercritical CO2 and for the synthesis of clay/aliphatic polyester nanocomposites. [less ▲]

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See detailRing opening polymerization
Lecomte, Philippe ULg; Jérôme, Robert ULg

in Kroschwitz, Jacqueline (Ed.) Encyclopedia of Polymer Science and Technology, Third Edition (2004)

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See detailRecent progress in the macromolecular engineering of aliphatic polyesters
Jérôme, Robert ULg; Li, Haiying; Rieger, Jutta et al

Conference (2004, July 04)

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See detailRing-opening polymerization of alpha-chloro-epsilon-caprolactone and chemical modification of poly(alpha-chloro-epsilon-caprolactone) by atom transfer radical processes
Lenoir, Sandrine ULg; Riva, Raphaël ULg; Lou, Xudong et al

in Macromolecules (2004), 37(11), 4055-4061

A highly versatile strategy was implemented in order to attach a range of polymer grafts and functional groups along the backbone of poly(epsilon-caprolactone). alpha-Chloro-epsilon-caprolactone ... [more ▼]

A highly versatile strategy was implemented in order to attach a range of polymer grafts and functional groups along the backbone of poly(epsilon-caprolactone). alpha-Chloro-epsilon-caprolactone (alphaClepsilonCL) was first prepared by the Baeyer-Villiger oxidation of alpha-chlorocyclohexanone. This monomer (alpha-Cl-epsilon-CL) was then copolymerized with epsilon-caprolactone in the presence of 2,2-dibutyl-2-stanna-1,3-dioxepane. Finally, the pendant activated chlorides of the copolymer were used to initiate (i) the "grafting from" of poly(methyl methacrylate) by atom transfer radical polymerization and (ii) the grafting of benzoate groups by atom transfer radical addition of 3-butenyl benzoate. [less ▲]

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See detailMacromolecular engineering of aliphatic polyesters
Lecomte, Philippe ULg

Scientific conference (2003, September)

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See detailCharge transfer complex inimer: A facile route to dendritic materials
Wang, Wenxin; Yan, Deyue; Bratton, Daniel et al

in Advanced Materials (2003), 15(16), 1348-1352

A versatile approach to the preparation of hyperbranched polymers, in which an inimer is used to assemble a charge transfer complex (CTC) with conventional vinyl monomers, is reported. A novel ... [more ▼]

A versatile approach to the preparation of hyperbranched polymers, in which an inimer is used to assemble a charge transfer complex (CTC) with conventional vinyl monomers, is reported. A novel hyperbranched fluoro-polymer (see Figure) has been successfully synthesized through the copolymerization of chlorotrifluoroethylene (CTFE) and p-(chloromethyl)styrene (CMS) by atom transfer radical polymerization (ATRP). [less ▲]

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See detailRecent progress in ring-opening of ε-caprolactone and derivatives
Lecomte, Philippe ULg; Jérôme, Robert ULg

Conference (2003, July 02)

This oral communication was presented by Philippe Lecomte

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See detail2-oxepane-1,5-dione: a precursor of a novel class of versatile semicrystalline biodegradable (co)-polyesters
Lecomte, Philippe ULg; Latere Dwan'Isa, Jean-Pierre; Dubois, Philippe et al

Poster (2003, July 01)

2-oxepane-1,5-dione (OPD) was synthesized by Baeyer-Villiger oxidation of 1,4-cyclohexanedione and ring-opening polymerized by 1-phenyl-2-propanol / tin octoate with formation of a semicrystalline ... [more ▼]

2-oxepane-1,5-dione (OPD) was synthesized by Baeyer-Villiger oxidation of 1,4-cyclohexanedione and ring-opening polymerized by 1-phenyl-2-propanol / tin octoate with formation of a semicrystalline polyester of high melting temperature (Tm: 147°C). A crystallographic study showed that the polyester is orthorombic in the P212121 space with two molecules extended along the c-axis as is the case for poly(ε-caprolactone) (PCL). Dibutyltin dimethoxide and 2,2-dibutyl-2-stanna-1,3-dioxepane (DSDOP) proved to be efficient initiators for the random copolymerization of ε-caprolactone (εCL) and OPD. Random distribution of the comonomer units was confirmed by DSC, 1H and 13C NMR analyses. A single Tm was observed, which varies regularly and monotonically with the OPD content as result of a cocrystallisation phenomenon. The single glass transition temperature (Tg) obeys the Fox equation. It is noteworthy that a copolymer containing 30 mol % OPD exhibits a Tm of 90°C. It is stable up to 140°C under nitrogen for one hour, such that processing by extrusion is quite possible. The OPD decomposition is maximum at 223°C for a heating rate of 10°C/min. The mechanism of thermal degradation was investigated and cleared up. The ketone increases the copolymer hydrophilicity and thus sensitivity to hydrolysis. The mechanical properties are quite reminiscent of PCL of comparable molecular weight. Quite interestingly, OPD imparts sensitivity to photo-cross-linking to this novel class of materials. [less ▲]

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See detailHydrolytic and thermal degradation of random copolyesters of epsilon-caprolactone and 2-oxepane-1,5-dione
Dwan'Isa Latere, Jean-Pierre; Lecomte, Philippe ULg; Dubois, Philippe ULg et al

in Macromolecular Chemistry and Physics (2003), 204(9), 1191-1201

The hydrolytic and thermal stability of random copolyesters of epsilon-caprolactone (epsilon-CL) and ca. 30 mol-% 2-oxepane-1,5-dione (OPD) have been investigated. Compared with poly(epsilon-caprolactone ... [more ▼]

The hydrolytic and thermal stability of random copolyesters of epsilon-caprolactone (epsilon-CL) and ca. 30 mol-% 2-oxepane-1,5-dione (OPD) have been investigated. Compared with poly(epsilon-caprolactone) (PCL) of a comparable molecular weight, the hydrolytic degradation of the copolyester is faster in a phosphate buffer (pH = 7.4) at 37°C as confirmed by the time dependence of water absorption, weight loss, melting temperature, and molecular weight. This difference is a result of the higher hydrophilicity imparted to the copolyester by the ketone of the OPD units. The thermal degradation has been studied by thermogravimetric analysis (TGA), (HNMR)-H-1 spectroscopy, and size exclusion chromatography (SEC). The activation energy of the thermal degradation under nitrogen has been found to be lower for the copolyesters than for PCL, which indicates that the OPD co-units have a deleterious effect on the thermal stability of PCL. The thermal degradation primarily occurs by pyrolysis of the ester functions. [less ▲]

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See detailPoly(α-chloro-ε-caprolactone), a new precursor for functionalized and graft polyesters
Riva, Raphaël ULg; Lenoir, Sandrine; Lecomte, Philippe ULg et al

Poster (2003, May 16)

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