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See detailThiophene derivatives with donor–π–acceptor structures for enhanced light-absorption properties and efficient cationic polymerization upon green-light irradiation
Telitel, Sofia; Ouhib, Farid ULg; Fouassier, Jean-Pierre et al

in Macromolecular Chemistry and Physics (2014), 215(16), 1514-1524

Positively charged thermoresponsive nanogels (NGs) are easily synthesized by precipitation polymerization of N-isopropyl­acrylamide and 2-dimethyl(aminoethyl)­methacrylate crosslinked with dendritic ... [more ▼]

Positively charged thermoresponsive nanogels (NGs) are easily synthesized by precipitation polymerization of N-isopropyl­acrylamide and 2-dimethyl(aminoethyl)­methacrylate crosslinked with dendritic polyglycerol. The NGs are characterized in terms of size, thermoresponsive properties, and Z potential. Their potential applications as drug delivery carriers are evaluated by the encapsulation and release of different anticancer drugs. As model drugs, doxorubicin and methotrexate are studied. [less ▲]

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See detailSurface-initiated controlled radical polymerization from silica nanoparticles with high initiator density
Chakkalakal, G. Louis; Alexandre, Michaël ULg; Abetz, Clarissa et al

in Macromolecular Chemistry and Physics (2012), 213(5), 513-528

The surface of silica nanoparticles is modified using the “grafting from” technique. A multi-step reaction is conducted to modify their surface properties. (3-glycidoxypropyl) trimethoxysilane (GPS) is ... [more ▼]

The surface of silica nanoparticles is modified using the “grafting from” technique. A multi-step reaction is conducted to modify their surface properties. (3-glycidoxypropyl) trimethoxysilane (GPS) is used as the coupling agent for the fixation of atom transfer radical polymerization (ATRP) initiator. The grafting efficiency of GPS mixed with aqueous suspension of silica nanoparticles is studied, followed by the coupling efficiency towards ATRP initiator. The bromide concentration of ATRP initiator is kept constant for comparative kinetic studies of styrene and MMA polymerizations. The consequences at high conversions and the particle size distribution are studied. The behaviour of the glass transition temperature of either polymer-modified particles and the nature of dispersion of polymer-coated silica particles are analyzed. [less ▲]

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See detailMultifunctional poly( ε-caprolactone)-forming networks by Diels–Alder cycloaddition: effect of the adduct on the shape-memory properties
Defize, Thomas ULg; Riva, Raphaël ULg; Jérôme, Christine ULg et al

in Macromolecular Chemistry and Physics (2012), 213(2), 187-197

Star-shaped poly(e-caprolactone)s are functionalized by various dienes (furan and anthracene) and a dienophile (maleimide), and the kinetics of network formation by melt-blending is compared for both ... [more ▼]

Star-shaped poly(e-caprolactone)s are functionalized by various dienes (furan and anthracene) and a dienophile (maleimide), and the kinetics of network formation by melt-blending is compared for both Diels–Alder adducts. When curing at 60 °C, the anthracene–maleimide network forms more rapidly and gives rise to a more crosslinked material than with the furan–maleimide adduct. Shape-memory properties of the networks are compared in terms of Diels–Alder adduct stability. Both materials exhibit excellent fixity and recovery ratios, but the relatively low retro Diels–Alder temperature of the furan–maleimide adduct perturbs the mechanical stability of the network during cyclic tensile testing between 0 and 60 °C, whereas the anthracene–maleimide adduct is shown to be stable up to 150 °C. [less ▲]

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See detailPolymerization of ortho-Substituted Phenylacetylenes with Well-Defined Ruthenium-Alkylidene Catalysts and Related Metathesis Initiators
Katsumata, T.; Shiotsuki, M.; Sanda, F. et al

in Macromolecular Chemistry And Physics (2009), 210(22), 1891-1902

The polymerization of (2-isopropoxyphenyl)acetylene was investigated using a wide range of well-defined ruthenium-alkylidene complexes and related olefin metathesis initiators. In view of its superior ... [more ▼]

The polymerization of (2-isopropoxyphenyl)acetylene was investigated using a wide range of well-defined ruthenium-alkylidene complexes and related olefin metathesis initiators. In view of its superior activity, the second generation Hoveyda-Grubbs catalyst was singled out for further studies. Only phenylacetylenes ortho-substituted with alkoxy, ester, fluoro, and silyl groups afforded polymers with moderate molecular weights. They were characterized by various analytical techniques, and their properties were pared with those of samples prepared using Rh and W initiators. The Ru-based polymers possessed high trans contents and took a helical conformation with predominantly one-handed screw sense when chiral side-chains were present. [less ▲]

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See detailMicellization of Poly(2-oxazoline)-Based Quasi-Diblock Copolymers on Surfaces
Fustin, Charles-André; Lefèvre, Nathalie ULg; Hoogenboom, Richard et al

in Macromolecular Chemistry and Physics (2007), 208

The micellization on surfaces of two series of quasi-diblock copoly(2-oxazoline)s consisting of 2-phenyl-2-oxazoline (PhOx) segments linked to either 2-methyl-2-oxazoline (MeOx) or 2-ethyl-2-oxazoline ... [more ▼]

The micellization on surfaces of two series of quasi-diblock copoly(2-oxazoline)s consisting of 2-phenyl-2-oxazoline (PhOx) segments linked to either 2-methyl-2-oxazoline (MeOx) or 2-ethyl-2-oxazoline (EtOx) segments is investigated in detail. Those micelles are not preexisting in the initial ethanol solution but are formed during the spin-coating process by the evaporation of the solvent inducing the precipitation of the less soluble PhOx segments. The morphology and size of the surface micelles vary according to the fraction of PhOx in the copolymers. Moreover, it is demonstrated that the chemical nature of the more soluble MeOx or EtOx segments also has an influence on the morphology of the resulting surface micelles. [less ▲]

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See detailAre electrografted polymers chemisorbed or physisorbed onto their substrate ?
Cuenot, Stéphane; Gabriel, Sabine ULg; Jérôme, Christine ULg et al

in Macromolecular Chemistry and Physics (2005), 206(12), 1216-1220

AFM-based single-molecule force spectroscopy was used to evaluate the mechanical strength of the link between a polymer and the substrate onto which the polymer is electrografted. Poly(N-succinimidyl ... [more ▼]

AFM-based single-molecule force spectroscopy was used to evaluate the mechanical strength of the link between a polymer and the substrate onto which the polymer is electrografted. Poly(N-succinimidyl acrylate) was electrografted onto gold substrates and brought into contact with an aminothiol-functionalized AFM tip. Bridging of single polymer chains resulting from the strong coupling between the activated esters on the polymer and amine groups on the tip was investigated. We found that the link between the polymer and the gold substrate can withstand a force far beyond the force characteristic for physisorption on gold. [less ▲]

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See detail(Plasticized) polylactide/(organo-)clay nanocomposites by in situ intercalative polymerization
Paul, Marie-Amélie; Delcourt, Cécile; Alexandre, Michaël ULg et al

in Macromolecular Chemistry and Physics (2005), 206(4), 484-498

Both intercalated and exfoliated poly(L,L-lactide) (P(L,L-LA)/organomodified montmorillonite nanocomposites were synthesized by in situ ring-opening polymerization Of L,L-lactide, in bulk, directly in the ... [more ▼]

Both intercalated and exfoliated poly(L,L-lactide) (P(L,L-LA)/organomodified montmorillonite nanocomposites were synthesized by in situ ring-opening polymerization Of L,L-lactide, in bulk, directly in the presence of the nanofiller. Intercalation of polyester chains was found to appear even for natural unmodified montmorillonite-Na+, while exfoliation occurred when the aluminosilicate layers were modified by ammonium cations bearing primary hydroxyl groups. Clay delamination was effectively triggered by the grafting reaction of the growing PLA chains onto the hydroxyl groups. Aluminium triisopropoxide, triethylaluminium, and stannous octoate, as initiating or co-initiating species, were compared in terms of polymerization control. The influence of nanoclay content (from 1 to 10 wt.-% in inorganics) on morphology and thermal behavior was also studied. In parallel, a highly filled nanocomposite (called masterbatch), prepared by in situ polymerization, was dispersed into a (plasticized) preformed polylactide matrix in the molten state, to reach a better clay delamination than that obtained by direct melt blending. Finally, L-,L-lactide and alpha,w-dihydroxylated poly(ethylene glycol) (PEG 1000) were copolymerized in presence of clay in order to study the behavior of the resulting triblocks towards nanocomposite formation. [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 detailDetermination of polyisoprene-block-poly(methyl methacrylate) domain sizes using 1H spin diffusion
Werkhoven, Thekla M; Mulder, Fokko M; Zune, Catherine et al

in Macromolecular Chemistry and Physics (2003), 204(1), 46-51

The microphase structure of polyisoprene-block-poly(methyl methacrylate) diblock copolymers was studied using solid-state NMR techniques. Wideline separation spectroscopy reveals a narrow interphase ... [more ▼]

The microphase structure of polyisoprene-block-poly(methyl methacrylate) diblock copolymers was studied using solid-state NMR techniques. Wideline separation spectroscopy reveals a narrow interphase between the two polymers. The domain sizes of a lamellar sample and a sample with hexagonally ordered cylinders were determined using 1H spin diffusion. The lamellar sample shows a domain size of 16 ± 2 nm for the minor polyisoprene phase and a long period of 33 ± 4 nm. The cylindrical structure has a long period of 38 ± 7 nm, the diameter of the PMMA cylinders is 21 ± 4 nm. These results are about 20% below the estimates obtained from theoretical calculations according to Helfand and Wasserman [less ▲]

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See detailControlled synthesis of anthracene-labeled omega-amine polystyrene to be used as a probe for interfacial reaction with mutually reactive PMMA
Yin, Zhihui; Koulic, Christian; Pagnoulle, Christophe et al

in Macromolecular Chemistry and Physics (2002), 203(14), 2021-2028

Anthracene-labeled polystyrene (PS) end-capped by a primary amine has been synthesized by atom transfer radical copolymerization of styrene with 3-isopropenyl-alpha,alpha-dimethylbenzyl isocyanate (m-TMI ... [more ▼]

Anthracene-labeled polystyrene (PS) end-capped by a primary amine has been synthesized by atom transfer radical copolymerization of styrene with 3-isopropenyl-alpha,alpha-dimethylbenzyl isocyanate (m-TMI). The m-TMI co-monomer (5.7 mol-%) does not perturb the control of the radical polymerization of styrene. The pendant isocyanate groups of the copolymer chains of low polydispersity (M-w/M-n = 1.25) and controlled molecular weight (up to 35 000) have been derivatized into anthracene by a reaction with 9-methyl(aminomethyl)anthracene. The anthracene-labeled PS (ca. 2 mol-% label) has been conveniently analyzed by size-exclusion chromatography with a UV detector (SEC-UV). Moreover, the omega-bromide end-group of the copolymer chains has been derivatized into a primary amine, making the labeled PS chains reactive towards non-miscible poly(methyl methacrylate) (PMMA) chains end-capped by an anhydride. The interfacial coupling of the mutually reactive PS and PMMA chains has been studied under static conditions (i.e., at the interface between thin PS and PMMA films) and successfully analyzed by SEC-UV. [less ▲]

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See detailThe use of epsilon-caprolactone as a polymerizable solvent for the atom transfer radical polymerization of MMA at low temperature
Wang, Wenxin; Yin, Zhihui; Detrembleur, Christophe ULg et al

in Macromolecular Chemistry and Physics (2002), 203(7), 968-974

This paper report on the decisive effect that solvent has on the atom transfer radical polymerization of methyl metacrylate (MMA) at low temperature. In buta-none and in the presence of a copper(I ... [more ▼]

This paper report on the decisive effect that solvent has on the atom transfer radical polymerization of methyl metacrylate (MMA) at low temperature. In buta-none and in the presence of a copper(I)/bipyridine com-plex the polymerization is controlled and the molecular weight distribution is narrow, at 0°C and even lower. This control is maintained when ε-caprolactone (CL) is substi-tuted for butanone. The use of this polymerizable solvent together with a novel dual initiator, 2-hydroxyethyl. 2'-methyl-2'bromopropionate, is an efficient strategy to pre pare PMMA-b-PCL diblock polymers in a one-pot process. [less ▲]

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See detailControl of the Radical Polymerization by 2,2,15,15-tetramethyl-1-aza-4,7,10,13-tetraoxacyclopentadecan-1-oxyl and its Sodium Salt
Olive, Gilles ULg; Rozanska, Xavier; Smulders, Wilfred et al

in Macromolecular Chemistry and Physics (2002), 203(12), 1790-1796

The control of the radical polymerization of styrene by 2,2,15,15-tetramethyl-1-aza-4,7,10,13-tetraoxacyclopentadecan-1-oxyl is reported here in bulk at 90 °C, 120 °C and in miniemulsion. Similarly, the ... [more ▼]

The control of the radical polymerization of styrene by 2,2,15,15-tetramethyl-1-aza-4,7,10,13-tetraoxacyclopentadecan-1-oxyl is reported here in bulk at 90 °C, 120 °C and in miniemulsion. Similarly, the control by its sodium complex is reported in bulk at 90 °C. [less ▲]

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See detailMetallocene catalyzed polymerization of ethylene in the presence of graphite. 1. Synthesis and characterization of the composites
Alexandre, Michaël ULg; Pluta, Miroslaw; Dubois, Philippe ULg et al

in Macromolecular Chemistry and Physics (2001), 202(11), 2239-2246

Polyethylene/graphite composites have been prepared by two different methods. In a first approach, the ethylene polymerization has been catalyzed by metallo-cene in the presence of neat graphite particles ... [more ▼]

Polyethylene/graphite composites have been prepared by two different methods. In a first approach, the ethylene polymerization has been catalyzed by metallo-cene in the presence of neat graphite particles (NGC composites). A second series of composites (TGC) has been prepared by the polymerization-filling technique, which requires that the metallocene/methylalumoxane catalyst is fixed onto the graphite surface prior to the ethylene polymerization. The two series of composites exhibit significantly different morphology and thermal properties. The filler distribution is very heterogeneous in the NGC series. The morphology changes from an intimate mixture of PE and filler particles at low graphite content to graphite covered by patches of PE at high filler loading. The graphite distribution is much more homogeneous in the TGC samples, and the morphology consists of particles covered by a layer of PE in the whole composition range. Differences in the thermal properties are discussed in relation to the morphology. [less ▲]

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See detailReactive compatibilization of SAN/EPR blends: Effect of rubber content and reactivity of the SAN functional groups
Pagnoulle, Christophe; Martin, Philippe; Jérôme, Robert ULg

in Macromolecular Chemistry and Physics (2000), 201(16), 2181-2194

SAN containing 20 wt.-% reactive SAN-X was melt blended with EPDM containing 50 wt.-% maleic anhydride EPR grafted chains (EP-g-MA). The rubber content was changed from 15 to 80 wt.-%, and 2 types of ... [more ▼]

SAN containing 20 wt.-% reactive SAN-X was melt blended with EPDM containing 50 wt.-% maleic anhydride EPR grafted chains (EP-g-MA). The rubber content was changed from 15 to 80 wt.-%, and 2 types of reactive groups (X) were attached to SAN (0.028 mol X/ wt.-%), i. e. primary amines and carbamates which are primary amine precursors at the processing temperature. Phase morphology, tensile properties and impact strength depend not only on the rubber content but also on the relative reactivity of the amine and the carbamate groups towards maleic anhydride, in a strong dependence on the reaction rate and the reaction completeness. The dispersion mechanism has been discussed, including formation of sub-inclusions. Dependence of the impact resistance on the rubber phase content for non-reactive blends (□) and blends modified by SAN-NH2 (;) and SAN-carb (o), respectively. [less ▲]

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See detailMorphology and rheology of poly(methyl methacrylate)-block-poly(isooctyl acrylate)-block-poly(mehtyl methacrylate) triblock copolymers, and potential as thermoplastic elastomers
Tong, Jiang-Dong; Leclère, Philippe; Rasmont, A. et al

in Macromolecular Chemistry and Physics (2000), 201(12), 1250-1258

The phase morphology and rheological properties of a series of poly(methyl methacrylate)-block-poly(isooctyl acrylate)-block-poly(methyl methacrylate) triblock copolymers (MIM) have been studied. These ... [more ▼]

The phase morphology and rheological properties of a series of poly(methyl methacrylate)-block-poly(isooctyl acrylate)-block-poly(methyl methacrylate) triblock copolymers (MIM) have been studied. These copolymers have well-defined molecular structures, with a molecular weight (MW) of poly(methyl methacrylate) (PMMA) in the range of 3 500-50 000 and MW of poly(isooctyl acrylate) (PIOA) ranging from 100 000 to 140 000. Atomic force microscopy with phase detection imaging has shown a two-phase morphology for all the MIM copolymers. The typical spherical, cylindrical, and lamellar phase morphologies have been observed depending on the copolymer composition. MIM consisting of very short PMMA end blocks (MW 3 500-5 000) behave as thermoplastic elastomers (TPEs), with however an upper-service temperature higher than the traditional polystyrene-block-polyisoprene-block-polystyrene TPEs (Kraton D1107). A higher processing temperature is also noted, consistent with the higher viscosity of PMMA compared to PS. [less ▲]

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See detailSynthesis of fully acrylic thermoplastic elastomers by atom transfer radical polymerization (ATRP), 2a effect of the catalyst on the molecular control and the rheological properties of the triblock copolymers
Moineau, Georges; Minet, Michaël; Teyssié, Philippe et al

in Macromolecular Chemistry and Physics (2000), 201(11), 1108-1114

The ATRP of MMA was initiated by α,ω-dibromo poly(n-butyl acrylate) in the presence of NiBr2(PPh3)2 leading to poly(MMA)-b-poly(nBuA)-b-poly(MMA) triblock copolymers (MnBM). The initiation of the MMA ... [more ▼]

The ATRP of MMA was initiated by α,ω-dibromo poly(n-butyl acrylate) in the presence of NiBr2(PPh3)2 leading to poly(MMA)-b-poly(nBuA)-b-poly(MMA) triblock copolymers (MnBM). The initiation of the MMA polymerization is slow compared to the chain propagation, which results in PMMA blocks of broad molecular weight distribution (MWD). In order to improve this situation, several experimental parameters were varied. CuBr/dNBipy was first substituted for NiBr2(PPh3)2, the results being, however, even worse. Then, the halide exchange was considered by substituting CuCl for CuBr. The CuCl/dNBipy catalyst proved superiority over the originally used NiBr2(PPh3)2 system. Finally, the addition of an excess of CuCl2 (deactivator) to the CuCl/dNBipy catalyst was very beneficial in decreasing the MWD of the PMMA blocks. Indeed, the SEC chromatograms are monomodal and narrow from the very beginning of the polymerization. The rheological analysis of the MnBM triblocks synthesized in the presence of each of the aforementioned catalytic systems confirmed differences in the molecular control of the copolymeriza-tion reaction. [less ▲]

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See detailSynthesis and characterization of non-covalent liquid crystalline diblock copolymers
Gohy, Jean-François; Antoun, Sayed; Sobry, Roger ULg et al

in Macromolecular Chemistry and Physics (2000), 201(1), 31-41

Poly(dimethylaminoethylmethacrylate)-b-poly(sodium methacrylate) diblocks, (polyDMAEMA-b-polyMA), were synthesized as precursors of liquid crystalline (LC) copolymers. These LC copolymers were prepared by ... [more ▼]

Poly(dimethylaminoethylmethacrylate)-b-poly(sodium methacrylate) diblocks, (polyDMAEMA-b-polyMA), were synthesized as precursors of liquid crystalline (LC) copolymers. These LC copolymers were prepared by pro-ton-transfer between a carboxylic acid-containing meso-gen (A) and the dimethylamino substituent of the poly-DMAEMA block and by electrostatic interactions between the polyMA subunits and an ammonium-contain-ing mesogen (B). When mesogen A is complexed with DMAEMA units, a dramatic enhancement of the meso-phase stability is noted. The mesogenic properties of these LC copolymers were compared to those ones of the parent LC homopolymers, in relation to the copolymer composi-tion. The supramolecular organization of the LC diblock copolymers was studied by small-angle X-ray scattering (SAXS), and smectic mesophases were observed in some LC (co)polymers. For samples containing a major LC block, a smectic mesophase coexists with microphases formed by the second amorphous block. Different organizations, including a body-centered lattice of spheres and a hexagonal array of cylinders, were observed, depending on the investigated copolymers and their composition. When the LC block is the minor component, it forms microdomains too small for a liquid crystalline order to emerge. Moreover, no supramolecular organization of these dispersed microdomains was detected by SAXS. A homogeneous smectic mesophase was observed when the two blocks are bearing liquid crystalline moieties. [less ▲]

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See detailFrom living to controlled aluminium alkoxide mediated ring-opening polymerization of (di)lactones, a powerful tool for the macromolecular engineering of aliphatic polyesters
Mecerreyes, David; Jérôme, Robert ULg

in Macromolecular Chemistry and Physics (1999), 200(12), 2581-2590

The aluminium alkoxide mediated ring-opening polymerization of (di)lactones offers a great versatility to the point where the main situations covered by the definition of living and controlled ... [more ▼]

The aluminium alkoxide mediated ring-opening polymerization of (di)lactones offers a great versatility to the point where the main situations covered by the definition of living and controlled polymerizations can be illustrated. Furthermore, substitution of a coordination-insertion mechanism for the traditional anionic polymerization of these monomers results in species of lower reactivity and in a kinetic control of the polyaddition reaction. This control, combined with the use of Al alkoxides of different structures and functionalities, has opened the way to the macromolecular design of a family of biocompatible and biodegradable polyesters, e.g., controlled synthesis of telechelic polymers, block and graft copolymers, and polymers of various molecular architectures. These polymers can be used as such, or as building parts of more sophisticated polymeric assemblies. [less ▲]

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See detailSynthesis of novel polybutadiene-graft-poly(sodium methacrylate) amphiphilic copolymers as precursors for liquid crystalline graft copolymers
Gohy, Jean-François; Charlier, Christelle; Zhang, Jian-Xin et al

in Macromolecular Chemistry and Physics (1999), 200(7), 1630-2638

Well-defined polybutadiene-graft-poly(tert-butyl methacrylate) (PBD-g-PtBMA) copolymers were prepared by reaction of PtBMA chains end-capped with a tert-butyl 4-vinylbenzoate (tBVB) anion, with the ... [more ▼]

Well-defined polybutadiene-graft-poly(tert-butyl methacrylate) (PBD-g-PtBMA) copolymers were prepared by reaction of PtBMA chains end-capped with a tert-butyl 4-vinylbenzoate (tBVB) anion, with the selectively hydrosilylated 1,2-units of anionically synthesized PBD. Substitution of the tBVB anion for the anion of living PtBMA chains is required for the formation of the expected C-silylation product instead of the unstable O-silylation one. Subsequent hydrolysis of the poly(tert-butyl methacrylate) grafts followed by neutralization of the carboxylic acid groups by sodium hydroxide leads to amphiphilic polybuta-diene-graft-poly(sodium methacrylate) (PBD-g-PNaMA) graft copolymers. These copolymers form unimeric micelles in water, as observed by dynamic light scattering (DLS). Non-covalent liquid crystalline graft copo-lymers were prepared by cation exchange between PBD-g-PNaMA copolymers and an ammonium containing smectic mesogen. These copolymers form a smectic mesophase which is microphase separated from PBD. [less ▲]

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See detailAnalysis of living tert-butyl methacrylate oligoanions in tetrahydrofuran by NMR spectroscopy, viscosity and light scattering
Zune, Catherine; Dubois, Philippe; Grandjean, Jean ULg et al

in Macromolecular Chemistry and Physics (1999), 200(3), 562-573

Previous kinetic studies concluded on the aggregation of the anionic chain ends of living tert-butyl methacrylate oligomers [PtBMA-, Li+] in THF at low temperature. This aggregation has been confirmed by ... [more ▼]

Previous kinetic studies concluded on the aggregation of the anionic chain ends of living tert-butyl methacrylate oligomers [PtBMA-, Li+] in THF at low temperature. This aggregation has been confirmed by viscosimetry, light scattering and gradient field NMR techniques in a range of temperature from 253 K to 298 K. These techniques have been systematically used for the analysis of both the living oligomers and the same chains recovered after hydrolysis of the anionic end groups. The structure of the growing anionic species was analyzed by means of 13C and 7Li NMR spectroscopy. 13C NMR required the selective labeling of the last monomer units by 13C atoms. [less ▲]

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