References of "Yin, Zhihui"
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See detailDependence of the interfacial reaction and morphology development on the functionality of the reactive precursors in reactive blending
Yin, Zhihui; Koulic, Christian; Pagnoulle, Christophe et al

in Macromolecular Symposia (2003), 198

PMMA containing 50 wt% of anthracene-labeled PMMA chains end-capped by a phthalic anhydride group (anth-PMMA-anh) has been melt blended at 180°C with PS containing 33 wt% of chains end-capped by an ... [more ▼]

PMMA containing 50 wt% of anthracene-labeled PMMA chains end-capped by a phthalic anhydride group (anth-PMMA-anh) has been melt blended at 180°C with PS containing 33 wt% of chains end-capped by an aliphatic primary amine (PS-NH2) and PS bearing 3.5 pendant amine groups (as an average) along the chains (PS-co-PSNBH2), respectively. The reactive chains have been synthesized by atom transfer radical polymerization. Conversion of anth-PMMA-anh into PS-b-PMMA and PS-g-PMMA copolymers has been monitored by SEC with a UV detector. The interfacial reaction mainly occurs in the initial melting and softening stage (<1.0 mm), although at a rate which strongly depends on the number of reactive groups attached to PS chains, the higher conversion being observed for the PS-co-PSNH2 containing blends. The phase morphology depends on the architecture of the in-situ formed copolymer Indeed, a coarser phase dispersion is observed in case of the graft copolymer compared to the diblock. [less ▲]

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See detailProbing of the reaction progress at a PMMA/PS interface by using anthracene-labeled reactive PS chains
Yin, Zhihui; Koulic, Christian; Pagnoulle, Christophe et al

in Langmuir (2003), 19(2), 453-457

The progress of the interfacial reaction of polystyrene chains end-capped by a primary amine (PS-NH2) and PMMA chains end-capped by an anhydride (PMMA-anh) has been monitored by SEC-UV, by using ... [more ▼]

The progress of the interfacial reaction of polystyrene chains end-capped by a primary amine (PS-NH2) and PMMA chains end-capped by an anhydride (PMMA-anh) has been monitored by SEC-UV, by using anthracene-labeled polystyrene chains (anth-PS-NH2) as a probe. Assemblies of an anth-PS-NH2 layer and a PMMA-anh layer were annealed at 200 degreesC for various periods of time. The interfacial reaction rate depends on the molecular weight (MW) of the reactive precursors in relation to the gammaN value of the chains. For chains of low gammaN (chiN = 6), the reaction is faster because the interface becomes more diffuse with time, as observed by TEM and AFM, consistent with compatibilization of the weakly immiscible polymers by the copolymer formed in-situ. For chains of higher molecular weight and chiN (10, instead of 6), the interface is much sharper and the residence time at the interface of the symmetric diblock copolymer of higher molecular weight is also increased, which dramatically restricts the progress of the interfacial reaction under the annealing conditions used in this work. [less ▲]

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See detailEffect of molecular weight of the reactive precursors in melt reactive blending
Yin, Zhihui; Koulic, Christian; Jeon, H. K. et al

in Macromolecules (2002), 35(24), 8917-8919

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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 detailVesicular nanostructures prepared by reactive melt blending
Koulic, Christian; Yin, Zhihui; Pagnoulle, Christophe et al

in Angewandte Chemie (International ed. in English) (2002), 41(12), 2154-2156

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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 detailReactive blending of functional PS and PMMA: interfacial behavior of in situ formed graft copolymers
Yin, Zhihui; Koulic, Christian; Pagnoulle, Christophe et al

in Macromolecules (2001), 34(15), 5132-5139

ω-Isocyanate PMMA, α-anhydride PMMA, and PS-co-PSNH2 have been prepared by atom transfer radical polymerization (ATRP) with controlled molecular weights (104 and 3.5 × 104) and low polydispersity (1.2 ... [more ▼]

ω-Isocyanate PMMA, α-anhydride PMMA, and PS-co-PSNH2 have been prepared by atom transfer radical polymerization (ATRP) with controlled molecular weights (104 and 3.5 × 104) and low polydispersity (1.2). They have been used as precursors of PS-g-PMMA copolymers and let to react in the melt (170 °C, for 10 min) under moderate shear rate. The well-controlled molecular characteristics of these precursors are a substantial advantage to study the effect of the kinetics of the interfacial reaction on the phase morphology. When the grafting reaction is fast (NH2/anhydride pair) and low molecular weight chains are used, the interfacial reaction is quasi-complete and a nanophase morphology is observed, whereas limited reaction and formation of microphases are observed in all the other cases. A high reaction yield requires not only that the functional groups are highly mutually reactive but also that the interface is anytime made available to the functional polymers for the reaction to progress. Then, a nanophase morphology may be observed, which is that of the copolymer formed by the interfacial reaction. A low reaction yield is dictated by either a slow interfacial reaction or a slow diffusion of the copolymer away from the interface. In the latter case, the phases formed by the unreacted precursors are stabilized by the copolymer which resides at the interface. [less ▲]

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See detailPremade versus in situ formed compatibilizer at the PS/PMMA interface: contribution of the Raman confocal microscopy to the fracture analysis
Koulic, Christian; Yin, Zhihui; Pagnoulle, Christophe et al

in Polymer (2001), 42(7), 2947-2957

The interface of a two-layer assembly of polystyrene (PS) and poly(methyl methacrylate) (PMMA) was modified by an intermediate layer of either a premade poly(styrene-g-methyl methacrylate) copolymer (P(S ... [more ▼]

The interface of a two-layer assembly of polystyrene (PS) and poly(methyl methacrylate) (PMMA) was modified by an intermediate layer of either a premade poly(styrene-g-methyl methacrylate) copolymer (P(S-g-MMA)) or a preblend of mutually reactive PS and PMMA synthesized by atom transfer radical polymerization (ATRP). No significant difference was found in the interfacial fracture toughness measured by the double cantilever beam test, although the morphology of the interfacial region was not the same when observed by transmission electron microscopy. The premade copolymer formed a distinct interphase, in contrast to the sharp interface that was observed in the case of the reactive system. The analysis of the fracture surfaces by Raman confocal microscopy showed that the fracture occurred alternatively in the PS phase and either at the PS/copolymer interface for the non reactive system or at the PS/PMMA interface for the reactive one. [less ▲]

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