References of "Macromolecules"
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See detailStructure and properties of a semifluorinated diblock copolymer modified epoxy blend
Ocando, Connie; Serrano, Elena; Tercjak, Agnieszka et al

in Macromolecules (2007), 40(11), 4068-4074

Novel nanostructured thermosetting materials have been prepared by modification of an epoxy resin with a semifluorinated diblock copolymer, poly(heptadecafluorodecyl acrylate)-b-poly(caprolactone), PaF-b ... [more ▼]

Novel nanostructured thermosetting materials have been prepared by modification of an epoxy resin with a semifluorinated diblock copolymer, poly(heptadecafluorodecyl acrylate)-b-poly(caprolactone), PaF-b-PCL. In a first step, the phase behavior and linear viscoelasticity of PaF-b-PCL were investigated. According to the segregation regime, no order-order transitions were detected, being the order-disorder transition temperature beyond the degradation temperature. Atomic force microscopy (AFM) images of the block copolymer after different thermal treatments revealed that self-assembly takes place into spherical nanodomains, which is consistent with the copolymer composition. This block copolymer was further used to prepare a nanostructured thermoset blend with an epoxy resin. DSC and DMA analysis reveals microphase separation of PaF block from the epoxy-rich phase after curing. The PaF block self-assembled into wormlike and spherical micelles in the thermoset system. This nanostructured blend presented unique surface properties showing high hydrophobicity (upsilon = 109 degrees) and low surface energy (17 mN/m). [less ▲]

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See detailCombination of ring-opening polymerization and "click" chemistry for the synthesis of an amphiphilic tadpole-shaped poly(epsilon-caprolactone) grafted by PEO
Li, Haiying; Riva, Raphaël ULg; Jérôme, Robert ULg et al

in Macromolecules (2007), 40(4), 824-831

A tadpole shaped poly(epsilon-caprolactone) (PCL; Mn = 24 500) was made amphiphilic by grafting the two PCL tails with PEO. In the first step, a macrocyclic PCL was synthesized by ring-opening ... [more ▼]

A tadpole shaped poly(epsilon-caprolactone) (PCL; Mn = 24 500) was made amphiphilic by grafting the two PCL tails with PEO. In the first step, a macrocyclic PCL was synthesized by ring-opening polymerization of epsilon-caprolactone (epsilon-CL) initiated by a cyclic tin(IV) dialkoxide and stabilized by local intramolecular photo-cross-linking. In the second step, the polymerization of a mixture of epsilon CL and alpha-chloro-epsilon-caprolactone (alpha Cl epsilon CL) was resumed with formation of two activated chloride containing PCL tails. In the third step, the chlorides were converted into azides onto which alkynyl end-capped PEO was grafted by the copper-mediated Huisgen's cycloaddition [3 + 2], thus giving a "click" reaction. The thermal properties of the final copolymer and the precursors were analyzed by differential scanning calorimetry. The amphiphilicity of the final copolymer was confirmed by micellization in water. [less ▲]

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See detailCombination of ring-opening polymerization and "click chemistry": Toward functionalization and grafting of poly(epsilon-caprolactone)
Riva, Raphaël ULg; Schmeits, Stéphanie; Jérôme, Christine ULg et al

in Macromolecules (2007), 40(4), 796-803

A straightforward strategy is proposed for the derivatization of poly(epsilon-caprolactone) (PCL). First, statistical copolymerization of alpha-chloro-epsilon-caprolactone (alpha-Cl-epsilon-CL) with ... [more ▼]

A straightforward strategy is proposed for the derivatization of poly(epsilon-caprolactone) (PCL). First, statistical copolymerization of alpha-chloro-epsilon-caprolactone (alpha-Cl-epsilon-CL) with epsilon-caprolactone (epsilon-CL) was initiated by 2,2-dibutyl-2-stanna-1,3-dioxepane (DSDOP). In a second step, pendent chlorides were converted into azides by reaction with sodium azide. Finally, duly substituted terminal alkynes were reacted with pendent azides by copper-catalyzed Huisgen's 1,3-dipolar cycloaddition, thus a "click" reaction. According to this strategy, pendent hydroxyl and acrylate groups and atom transfer radical polymerization (ATRP) initiators were successfully attached to PCL. Similarly, amphiphilic graft copolymers were prepared by cycloaddition of an alkyne end-capped poly(ethylene oxide) (PEO) onto the azide substituents of the copolyester. The dependence of the grafting yield on the experimental conditions of the "click" reaction, i.e., temperature, solvent, and catalyst, was investigated. This strategy is very versatile because a large variety of aliphatic polyesters can be easily synthesized from a single precursor, easily prepared from commercially available compounds, merely by changing the alkyne involved in the Huisgen's 1,3-dipolar cycloaddition. Last but not least, PCL subsituted by azide groups does not have to be isolated after substitution of chlorides by sodium azide, and the "click" reaction can be carried out in a "one-pot" process. [less ▲]

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See detailCobalt-mediated radical polymerization (CMRP) of vinyl acetate initiated by redox systems: Toward the scale-up of CMRP
Bryaskova, Rayna ULg; Detrembleur, Christophe ULg; Debuigne, Antoine ULg et al

in Macromolecules (2006), 39(24), 8263-8268

A redox initiating system was developed in order to bypass 2,2'-azobis(4-methoxy-2,4-dimethylvaleronitrile) (V70) as the initiator of the cobalt-mediated radical polymerization (CMRP) of vinyl acetate ... [more ▼]

A redox initiating system was developed in order to bypass 2,2'-azobis(4-methoxy-2,4-dimethylvaleronitrile) (V70) as the initiator of the cobalt-mediated radical polymerization (CMRP) of vinyl acetate (VAc) in the presence of cobalt(II) acetylacetonate (Co(acac)(2)). It is indeed a problem to stock up with V70 because of needed storage at -20 degrees C during transportation. This paper reports on the controlled CMRP of VAc initiated by ascorbic acid combined with either lauroyl peroxide or benzoyl peroxide at 30 degrees C. Substitution of citric acid for ascorbic acid results in faster polymerization whereas the polymerization control is maintained. All these improvements facilitate the implementation of the vinyl acetate CMRP and open the door to the scale-up of the process. [less ▲]

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See detailExperimental and theoretical investigation of the lamellar structure of a styrene-butyl methacrylate diblock copolymer by fluorescence resonance energy transfer, small-angle X-ray scattering, and self-consistent-field simulations
Spiro, John G; Yang, Jiahn; Zhang, Jian-Xin et al

in Macromolecules (2006), 39(20), 7055-7063

We have investigated the repeat distance and interface thickness, at 160 degrees C, of a poly(styrene-b-butyl methacrylate) (PS-b-PBMA) diblock copolymer of similar to 180 000 molecular weight by small ... [more ▼]

We have investigated the repeat distance and interface thickness, at 160 degrees C, of a poly(styrene-b-butyl methacrylate) (PS-b-PBMA) diblock copolymer of similar to 180 000 molecular weight by small- angle X-ray scattering (SAXS) and fluorescence resonance energy transfer ( FRET). We have found a lamellar period of 47 nm and an interface thickness of 5 nm. A simple, hyperbolic secant model of the junction distribution appeared to be sufficient to analyze the fluorescence decay data on the junction-labeled polymer containing different acceptor/donor ratios, but simulations based on a numerical self- consistent-field (NSCF) formalism also allowed us to find a range of approximately 0.017-0.018 for the Flory-Huggins interaction parameter (chi(FH), defined with reference to the monomeric volume of polystyrene) and a PBMA Kuhn length (b(PBMA)) of 0.65-0.67 nm. We note that earlier values of chi(FH) and b(PBMA) reported in the literature vary considerably. The NSCF computations suggest that even modest levels of conformational asymmetry perturb the block copolymer morphology. A weakness of our theoretical (NSCF) approach is the compressible nature of PS-b-PBMA. However, lattice cluster, equation of state (EOS), or other models that allow for compressibility have not yet been developed to the level of sophistication needed to predict block copolymer repeat distances or interface thicknesses. Indeed, as detailed in the Supporting Information, current EOS methods leave much to be desired even in predicting the phase transitions of lower molecular weight PS-b-PBMA samples. [less ▲]

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See detailSynthesis of novel amphiphilic and pH-sensitive ABC miktoarm star terpolymers
Van Butsele, Kathy ULg; Stoffelbach, François; Jérôme, Robert ULg et al

in Macromolecules (2006), 39(17), 5652-5656

Novel amphiphilic ABC miktoarm star terpolymers were synthesized that consist of hydrophilic poly( ethylene oxide) (PEO), hydrophobic poly(is an element of-caprolactone) (PCL), and pH-sensitive poly(2 ... [more ▼]

Novel amphiphilic ABC miktoarm star terpolymers were synthesized that consist of hydrophilic poly( ethylene oxide) (PEO), hydrophobic poly(is an element of-caprolactone) (PCL), and pH-sensitive poly(2-vinylpyridine) (P2VP), thus a water-soluble block upon protonation. In the first step, poly( ethylene oxide monomethyl ether) (MPEO) was capped by one omega-epoxy end group by reaction of the original hydroxy end group with epichlorohydrin. MPEO-b-P2VP diblock copolymers were prepared by nucleophilic addition of living P2VP-Li+ chains onto the epoxy group of MPEO's. Finally, the hydroxy group formed at the junction of the MPEO and P2VP blocks was used to initiate the ring-opening polymerization of is an element of-caprolactone in the presence of tin octoate. The ABC starshaped triblocks were characterized by H-1 NMR spectroscopy and size exclusion chromatography. [less ▲]

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See detailStable free radical polymerization of acrylates promoted by α-hydroxycarbonyl compounds
Debuigne, Antoine ULg; Radhakrishnan, Thottackad; Georges, Michaël K.

in Macromolecules (2006), 39(16), 5359-5363

The living-radical polymerization of n-butyl acrylate, moderated with TEMPO, is shown to proceed in a controlled fashion in the presence of a series of α-hydroxycarbonyl compounds with different organic ... [more ▼]

The living-radical polymerization of n-butyl acrylate, moderated with TEMPO, is shown to proceed in a controlled fashion in the presence of a series of α-hydroxycarbonyl compounds with different organic bases. The best results were obtained with glyceraldehyde dimer in the presence of pyridine. These results further support the suggestion that the difficulty of polymerizing acrylate monomers in the presence of TEMPO is related to the excess buildup of TEMPO due to a small amount of polymer chain termination and to a lesser extent on the higher bond dissociation energy of the TEMPO acrylate bond relative to the TEMPO styrene bond at the chain's terminus. [less ▲]

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See detailpH-Responsive diblock copolymers prepared by the dual initiator strategy
Bernaerts, Katrien V.; Willet, Nicolas ULg; Van Camp, Wim et al

in Macromolecules (2006), 39(11), 3760-3769

Diblock copolymers poly(tetrahydrofuran-b-tert-butyl acrylate) (PTHF-b-PtBA) and poly(tetrahydrofuranb- 1-ethoxyethyl acrylate) (PTHF-b-PEEA) were successfully synthesized by the dual initiator 4 ... [more ▼]

Diblock copolymers poly(tetrahydrofuran-b-tert-butyl acrylate) (PTHF-b-PtBA) and poly(tetrahydrofuranb- 1-ethoxyethyl acrylate) (PTHF-b-PEEA) were successfully synthesized by the dual initiator 4-hydroxybutyl-2- bromoisobutyrate (HBBIB). The isobutyrate and alcohol function of HBBIB were used for the atom transfer radical polymerization of tBA ( or EEA) and the living cationic ring-opening polymerization of THF, respectively. Hydrolysis or thermolysis of the aforementioned diblock copolymers results in amphiphilic pH-responsive copolymers PTHF-b-poly( acrylic acid) ( PTHF-b-PAA). Matrix-assisted laser desorption/ ionization time-of-flight (MALDI-TOF) and nuclear magnetic resonance spectroscopy (H-1 NMR) were used to analyze the PTHF macroinitiator, while clear evidence for the formation of well-defined block copolymer structures was obtained by 1H NMR, gel permeation chromatography (GPC), and infrared spectroscopy (FT-IR). The amorphous PtBA block in PTHF-b-PtBA resulted in a decrease of the crystallinity and the melting point of PTHF, as shown by differential scanning calorimetry (DSC). Self-assembly of PTHF-b-PAA copolymers in water into aggregates and micelles when exposed to specific pH values was confirmed by dynamic light scattering, infrared, and NMR spectroscopies. [less ▲]

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See detailDithioesters and Trithiocarbonates as Anchoring Groups for the "Grafting-To" Approach
Duwez, Anne-Sophie ULg; Guillet, Pierre; Collard, Catheline et al

in Macromolecules (2006), 39

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See detailFirst insights into electrografted polymers by AFM-based force spectroscopy
Cuenot, Stéphane; Gabriel, Sabine ULg; Jérôme, Robert ULg et al

in Macromolecules (2006), 39(24), 8428-8433

The very first characterization of the structural properties of polymer films obtained by electrografting is reported. AFM-based force spectroscopy was used to investigate poly-N-succinimidyl acrylate ... [more ▼]

The very first characterization of the structural properties of polymer films obtained by electrografting is reported. AFM-based force spectroscopy was used to investigate poly-N-succinimidyl acrylate (PNSA) layers electrografted directly from a silicon substrate. Quantitative analysis of compression profiles obtained in a good solvent and single molecule bridging interaction, in light of the Alexander-de Gennes model, gave access to the grafting density and degree of polymerization. A high swelling capacity has been evidenced. This report is the first evidence that polymers obtained by cathodic electrografting are in fact brush systems, and consequently the first evidence that a polymer brush can be obtained from a direct "grafting from" method, without any intermediate layer. [less ▲]

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See detailControlled synthesis of an ABC miktoarm star-shaped copolymer by sequential ring-opening polymerization of ethylene oxide, benzyl beta-malolactonate, and epsilon-caprolactone
Rieger, Jutta ULg; Coulembier, Olivier; Dubois, Philippe ULg et al

in Macromolecules (2005), 38(26), 10650-10657

This paper reports on the synthesis of an amphiphilic miktoarm ABC star-shaped copolymer, s[(PEO)(PMLABz)(PCL)], consisting of biocompatible/bioresorbable arms. Indeed, PEO is a hydrophilic biocompatible ... [more ▼]

This paper reports on the synthesis of an amphiphilic miktoarm ABC star-shaped copolymer, s[(PEO)(PMLABz)(PCL)], consisting of biocompatible/bioresorbable arms. Indeed, PEO is a hydrophilic biocompatible poly(ethylene oxide) arm, PMLABz is a poly(benzyl beta-malolactonate) arm precursor of a pH-sensitive bioresorbable poly(beta-malic acid) block, and PCL is a hydrophobic bioresorbable poly(epsilon-caprolactone) arm. Each constitutive arm was prepared by ring-opening polymerization. A double-headed PEO macroinitiator [PEO-(OH)-COO-K+] was first prepared by selective hydrolysis of the alpha-lactone (2-oxepanone) end group of PEO chains end-capped by a omega-methoxy group. The anionic polymerization of benzyl beta-malolactonate (MLABz) was selectively initiated by the alpha-potassium carboxylate end group of PEO in the presence of 18-crown-6 ether. The polymerization of epsilon-caprolactone (epsilon-CL) was initiated by the hydroxyl group left at the junction of the two blocks of the as-prepared PEO-b-PMLABz diblock copolymer, in the presence of tin(II) bis(2-ethylhexanoate) (Sn(Oct)(2)). The macroinitiator, the intermediate diblock, and the final miktoarm. star-shaped copolymer were analyzed by H-1 NMR spectroscopy and size exclusion chromatography. [less ▲]

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See detailSynthesis of poly(vinyl acetate) and poly(vinyl alcohol) containing block copolymers by combination of cobalt-mediated radical polymerization and ATRP
Debuigne, Antoine ULg; Caille, Jean-Raphaël; Willet, Nicolas ULg et al

in Macromolecules (2005), 38(23), 9488-9496

Poly(vinyl acetate) (PVAc) chains of a low polydispersity (Mw/Mn similar to 1.1-1.2) have been prepared by cobalt-mediated radical polymerization of vinyl acetate (VAc). They have been end-capped by an ... [more ▼]

Poly(vinyl acetate) (PVAc) chains of a low polydispersity (Mw/Mn similar to 1.1-1.2) have been prepared by cobalt-mediated radical polymerization of vinyl acetate (VAc). They have been end-capped by an activated bromide by addition of an alpha-bromoester or an alpha-bromoketone containing nitroxide and converted into effective macroinitiators for the atom transfer radical polymerization of styrene (Sty), ethyl acrylate, and methyl methacrylate. Because each block is formed by a controlled process, well-defined PVAc containing diblock copolymers are easily prepared. The PVAc-b-PS copolymers synthesized from alpha-bromoketone end-capped PVAc can be converted into well-defined poly(vinyl alcohol)-b-polystyrene amphiphiles by methanolysis of the poly(vinyl acetate) block. Self-association of an amphiphilic poly(vinyl alcohol)(3500)-b-polystyrene(16 600) in a (4/1) water/tetrahydrofuran mixture results in the formation of vesicles as observed by transmission electron microscopy. [less ▲]

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See detailQuinone transfer radical polymerization of styrene catalyzed by metal complexes in the presence of various o-quinones
Debuigne, Antoine ULg; Caille, Jean-Raphaël; Jérôme, Robert ULg

in Macromolecules (2005), 38(15), 6310-6315

Several o-quinones have been tested as control agents for the quinone transfer radical polymerization (QTRP) of styrene in the presence of cobalt(II) acetylacetonate. In contrast to the commercially ... [more ▼]

Several o-quinones have been tested as control agents for the quinone transfer radical polymerization (QTRP) of styrene in the presence of cobalt(II) acetylacetonate. In contrast to the commercially available 3,5-di-tert-butyl-o-benzoquinone (3,5-DtBBQ) and tetrachloro-1,2-benzoquinone (tetrachloro-1,2-BQ), 3,6-dimethoxy-9,10-phenanthrenequinone (3,6-DMPhQ) imparts a better control to the radical polymerization of styrene compared to 9,10-phenanthrenequinone (PhQ) used as a reference. Indeed, whenever 3,6-DMPhQ is added with a catalytic amount of metal complexes (Co(acac)(2) or Al(acac)(3)), the evolution of the molar mass with the monomer conversion is linear, and low polydispersity (M-w/M-n similar to 1.1-1.2) is observed until very high monomer conversion (similar to 90%). Finally, the methoxy protons of 3,6-DMPhQ have been detected by H-1 NMR analysis of the polystyrene end groups, which is important mechanistic information. [less ▲]

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See detailSynthesis of end-functional poly(vinyl acetate) by cobalt-mediated radical polymerization
Debuigne, Antoine ULg; Caille, Jean-Raphaël; Jérôme, Robert ULg

in Macromolecules (2005), 38(13), 5452-5458

Poly(vinyl acetate) (PVAc) chains prepared by cobalt-mediated radical polymerization in the presence of cobalt(II) acetylacetonate (Co(acac)(2)) were quenched by radical scavengers, such as thiol ... [more ▼]

Poly(vinyl acetate) (PVAc) chains prepared by cobalt-mediated radical polymerization in the presence of cobalt(II) acetylacetonate (Co(acac)(2)) were quenched by radical scavengers, such as thiol compounds and nitroxides, to displace the covalently bonded Co(acac)(2) moiety and to end-cap them with a reactive group. The cobalt complex was completely removed by filtration, as confirmed by the induction coupled plasma (ICP) analysis of the polymer before and after treatment. Growing poly(vinyl acetate) chains can be end-functionalized either by addition of an appropriately functionalized nonpolymerizable olefin or by displacement of the Co(acac)(2) moiety by a functionalized nitroxide. This strategy allows PVAc to be synthesized with a predictable molecular weight, a reasonably low polydispersity (M-w/M-n similar to 1.1-1.3), and a functional omega end group, e.g., hydroxyl and epoxy. [less ▲]

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See detailControlled radical polymerization of styrene by quinone transfer radical polymerization (QTRP)
Caille, Jean-Raphaël; Debuigne, Antoine ULg; Jérôme, Robert ULg

in Macromolecules (2005), 38(1), 27-32

Radical polymerization of styrene falls under control when conducted at 100 degreesC, in the presence of an ortho-quinone, e.g., phenanthrenequinone (PhQ): and a catalytic amount of cobalt(II ... [more ▼]

Radical polymerization of styrene falls under control when conducted at 100 degreesC, in the presence of an ortho-quinone, e.g., phenanthrenequinone (PhQ): and a catalytic amount of cobalt(II) acetylacetonate. Criteria for a controlled chain polymerization are fulfilled at least until 50% of monomer conversion, i.e., molar mass increasing with monomer conversion. molar mass predictable from the styrene/ quinone molar ratio, linear time dependence of ln([M](o)/[M]), and effective resumption of Styrene polymerization by preformed oligopolystyrene. A tentative mechanism is proposed for this new System designated as quinone transfer radical polymerization (QTRP). [less ▲]

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See detailLactone end-capped poly(ethylene oxide) as a new building block for biomaterials
Rieger, Jutta ULg; Bernaerts, Katrien V.; Du Prez, Filip E et al

in Macromolecules (2004), 37(26), 9738-9745

This paper reports on the synthesis of a novel poly(ethylene oxide) (PEO) macromonomer, which can be copolymerized with epsilon-caprolactone (epsilon-CL) by ring-opening polymerization (ROP). PEO chains ... [more ▼]

This paper reports on the synthesis of a novel poly(ethylene oxide) (PEO) macromonomer, which can be copolymerized with epsilon-caprolactone (epsilon-CL) by ring-opening polymerization (ROP). PEO chains end-capped by an epsilon-caprolactone unit (gammaPEO(.)CL) have been synthesized by living anionic ring-opening polymerization of ethylene oxide (EO) initiated by the potassium alkoxide of 1,4-dioxaspiro[4.5]decan-8-ol, followed by derivatization of the acetal into a ketone and the Baeyer-Villiger oxidation of the ketone into a lactone. The end-capping of PEO by epsilon-CL was assessed by FTIR, MALDI-TOF, and H-1 NMR spectroscopy. This type of macromonomer is a precursor of amphiphilic comblike copolymers consisting of a biodegradable hydrophobic backbone of poly-(epsilon-caprolactone) (PCL) and hydrophilic PEO grafts. Copolymerization of gammaPEO(.)CL with epsilon-CL was successfully initiated by aluminum alkoxide. [less ▲]

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See detailFormation of polyamide 12-polyisoprene core-shell particles in polystyrene by reactive blending
Koulic, Christian; François, G.; Jérôme, Robert ULg

in Macromolecules (2004), 37(14), 5317-5322

Polyamide 12 (PA12)-polyisoprene (PIP) particles with a thermoplastic core and a rubbery shell have been prepared in a thermoplastic matrix (PS) by reactive blending. For this purpose, an anhydride-end ... [more ▼]

Polyamide 12 (PA12)-polyisoprene (PIP) particles with a thermoplastic core and a rubbery shell have been prepared in a thermoplastic matrix (PS) by reactive blending. For this purpose, an anhydride-end-capped PS-b-PIP diblock (PS-b-PIP-anh) has been reacted with PA12 chains end-capped (50% of them) by a primary amine and dispersed in PS. A PS-b-PIP-PA12 triblock has been formed at the interface between the PS matrix and the dispersed PA12 microdomains. Thus, the phase morphology consists of PA12 core-PIP shell particles dispersed in PS. The nonreacted PA12 with respect to PS-b-PIP-anh dictates the size of the polyamide (core) domains, and the reactive diblock (mainly the molecular weight of the PIP block) imposes the shell thickness and modulates the core size by its capacity to compatibilize PA12 and the thermoplastic matrix. [less ▲]

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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 detailNanostructured polyamide by reactive blending. 1. Effect of the reactive diblock composition
Koulic, Christian; Jérôme, Robert ULg

in Macromolecules (2004), 37(9), 3459-3469

Reactive blending of phthalic anhydride end-capped polystyrene-b-polyisoprene diblock (PS-b-PIP-anh) with 80 wt % of polyamide 12 (PA12) results in the very rapid formation of a PS-b-PIP-b-PA triblock ... [more ▼]

Reactive blending of phthalic anhydride end-capped polystyrene-b-polyisoprene diblock (PS-b-PIP-anh) with 80 wt % of polyamide 12 (PA12) results in the very rapid formation of a PS-b-PIP-b-PA triblock copolymer, which self-assembles with formation of characteristic nanoobjects, within the polyamide matrix. For instance, a vesicular nanostructure is formed in the particular case of a symmetric, lamellar-forming diblock copolymer. This morphology actually complies with the lower curvature possible for ABC lamellae diluted in a continuous C phase under shear. In contrast, when the diblock composition is typically asymmetric (at constant molecular weight), vesicles disappear in favor of a core-shell morphology with a cucumber-like suborganization. This spontaneous nanostructuration of the PA12 matrix is quite general. Indeed substitution of an amorphous primary amine end-capped styrene/acrylonitrile random copolymer (SAN-NH2) for PA12 results in exactly the same phase morphology upon reactive blending with PS-b-PIP-anh. [less ▲]

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See detailNanostructured PMMA: from lamellar sheets to double-layered vesicles
Koulic, Christian; Jérôme, Robert ULg

in Macromolecules (2004), 37(3), 888-893

PMMA was nanostructured by similar to100 nm liposome-like vesicular objects by melt blending with 20 wt % of a symmetric poly(styrene)-b-poly(isoprene)-b-poly(methyl methacrylate) (PS-b-PIP-b-PMMA ... [more ▼]

PMMA was nanostructured by similar to100 nm liposome-like vesicular objects by melt blending with 20 wt % of a symmetric poly(styrene)-b-poly(isoprene)-b-poly(methyl methacrylate) (PS-b-PIP-b-PMMA) triblock copolymer in the dry-brush regime. Whenever the blend was prepared by casting toluene solution, thus under zero-shear conditions, a continuous network of lamellar copolymer sheets was formed in PMMA, which however underwent a transition to the aforementioned vesicles upon application of large amplitude oscillatory shear. [less ▲]

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