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Philippe Dubois - One of the best experts on this subject based on the ideXlab platform.
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Novel polyesteramide-based di- and triblock copolymers From thermo-mechanical properties to hydrolytic degradation
European Polymer Journal, 2011Co-Authors: Gaëlle Deshayes, Ingrid Verbruggen, Lise Trouillet-fonti, Franck Touraud, Rudolph Willem, Philippe Degée, Mathias Destarac, Etienne Fleury, Cécile Delcourt, Philippe DuboisAbstract:Two types of biodegradable poly(epsilon-caprolactone (CLo))-co-poly(epsilon caprolactam (CLa)) copolymers were prepared by catalyzed hydrolytic ring-opening polymerization For the first type of materials the respective cyclic comonomers were added simultaneously in the reaction medium leading to the formation of copolymers having a random distribution of co-units within the polyesteramide sequence as evidenced by H-1 and C-13 NMR For the second type of copolymers the cyclic comonomers were added sequentially in the reaction medium yielding diblock polyesteramides again evidenced by NMR The thermal and thermo-mechanical properties of the copolymers were investigated by DSC and DMA and correlated with the copolymer topology and composition The copolymers were char acterized by a storage modulus and alpha transition temperature intermediate to the modulus and T-g of the corresponding homopolymers The chemical composition and molecular weight of the copolymers proved to have only a limited effect on the thermo-mechanical properties of the materials The hydrolytic degradation of random copolymers was studied in a phosphate buffer at 60 degrees C and discussed in terms of chemical composition and molecular weight of the copolymers
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handbook of ring opening polymerization
2009Co-Authors: Philippe Dubois, Olivier Coulembier, Jeanmarie RaquezAbstract:THERMODYNAMICS AND KINETICS OF RING-OPENING POLYMERIZATION Introduction Thermodynamics of the Ring-Opening Polymerization Kinetics of Ring-Opening Polymerization GENERAL MECHANISMS IN RING-OPENING POLYMERIZATION Introduction Anionic Ring-Opening Polymerization Cationic Ring-Opening Polymerization Radical Ring-Opening Polymerization SILOXANE-CONTAINING POLYMERS Introduction Polydimethylsiloxanes Functional Silicones Polycarbosiloxanes SULFUR-NITROGEN-PHOSPHOROUS-CONTAINING POLYMERS Introduction Mechanism and Methods in Ring-Opening Polymerization (ROP) of Halogenated Cyclotriphosphazanes Ring-Opening Polymerization and Chemistry of Nonhalogenated Phosphazane Rings Incorporation of Sulfur into Phosphazane Ring Systems and Their Polymerization Chemistry POLYMERIZATION OF CYCLIC DEPSIPEPTIDES, UREAS AND URETHANES Introduction Polydepsipeptides Monomers Ring-Opening Polymerization Enzymatic Polymerization Ring Expansion Polyureas Polyurethanes POLYETHERS AND POLYOXAZOLINES Introduction Polyethers Polyoxazolines POLYAMIDES Introduction Mechanism of the Anionic Polymerization of Lactams Initiators for the Anionic Polymerization of Lactams Activators for Anionic Polymerization of Lactams Nonactivated Polymerization Cyclic Oligomers of Epsilon-Caprolactam Block Copolymers of Lactams Anionic Copolymerization of Epsilon-Caprolactam with Omega-Laurolactam Copolymerization of Lactams with Lactones (Epsilon-Caprolactone) Powdered Polyamide Nanocomposites Anionic Polymerization of 2-Pyrrolidone RING-OPENING METATHESIS POLYMERIZATION General Introduction Introduction to Ring-Opening Metathesis Polymerization (ROMP) Well-Defined Catalysts for ROMP 'Living? ROMP Selected Recent Applications and Developments POLYESTERS FROM BETA-LACTONES Introduction Beta-Lactones Preparation Ionic Polymerization Coordination Process Carbene-Based Polymerization Enzymatic Polymerization Illustrative Experimental Section POLYESTERS FROM DILACTONES Introduction General Concepts and ROP Promoted by Metallic Recent Advances in ROP Macromolecular Engineering Applications POLYESTERS FROM LARGE LACTONES Introduction Controlled Synthesis of Linear Polyesters Physical Properties of Polymers POLYCARBONATES Introduction Polymerization of Cyclic Carbonates: Homopolymers and Block Copolymers POLYMERIZATION OF CYCLOALKANES Introduction General Overview and Thermodynamic Requirements Structure-Reactivity Relationships Based on a Comprehensive Survey of the Current Literature METAL-FREE CATALYSIS IN RING-OPENING POLYMERIZATION Introduction Nucleophilic ROP Metal-Free Ionic ROP ENZYME-MEDIATED RING-OPENING POLYMERIZATION Introduction Characteristics of Enzymatic ROP Classes of Monomer Polymer Architectures Employing Enzymatic ROP
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Activation of the hydrolytic polymerization of Epsilon-Caprolactam by ester functions: Straightforward route to aliphatic polyesteramides
Reactive and Functional Polymers, 2008Co-Authors: Gaëlle Deshayes, Ingrid Verbruggen, Lise Trouillet-fonti, Franck Touraud, Rudolph Willem, Philippe Degée, Mathias Destarac, Etienne Fleury, Cécile Delcourt, Philippe DuboisAbstract:The hydrolytic polymerization of ε-caprolactam (CLa) was carried out in bulk (in absence of solvent) at 250 °C in the presence of carboxylic esters and aqueous H3PO2. It turned out that by conducting the ring opening polymerization (ROP) of CLa in the presence of PEO-C(O)-O-C5H11, a selected model ester (PEO = poly(ethylene oxide)), a remarkable activating effect of the ester function on the hydrolytic polymerization of the lactam was observed yielding PEO-b-PCLa diblock copolymers. The comparison of the CLa monomer conversions obtained with or without the model ester activated by H3PO2, as determined by 1H NMR spectroscopy, has enabled to propose a multi-step mechanism in which three major reactions occurred: (i) ester and lactam hydrolysis, (ii) aminolysis of the carboxylic ester by the resulting primary amine of the hydrolyzed/opened lactam ring and (iii) condensation reactions between carboxylic acids and both amine/hydroxyl functions. The overall result of this multi-step mechanism can be assimilated as an “insertion” of the opened lactam into the ester function. By conducting the hydrolytic polymerization of CLa in the presence of an aliphatic polyester chain, such as poly(ε-caprolactone) (PCLo), polyesteramides were recovered with high yields and random distributions of the CLa and CLo repetitive units as determined by 13C NMR.
Michele Parrinello - One of the best experts on this subject based on the ideXlab platform.
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hydrogen bond driven chemical reactions beckmann rearrangement of cyclohexanone oxime into epsilon caprolactam in supercritical water
Journal of the American Chemical Society, 2004Co-Authors: Mauro Boero, Tamio Ikeshoji, Chee Chin Liew, Kiyoyuki Terakura, Michele ParrinelloAbstract:Recent experiments have shown that supercritical water (SCW) has the ability to accelerate and make selective synthetic organic reactions, thus replacing the common but environmentally harmful acid and basic catalysts. In an attempt to understand the intimate mechanism behind this observation, we analyze, via first-principles molecular dynamics, the Beckmann rearrangement of cyclohexanone oxime into e-caprolactam in supercritical water, for which accurate experimental evidence has been reported. Differences in the wetting of the hydrophilic parts of the solute, enhanced by SCW, and the disrupted hydrogen bond network are shown to be crucial in triggering the reaction and in making it selective. Furthermore, the enhanced concentrations of H+ in SCW play an important role in starting the reaction.
Gaëlle Deshayes - One of the best experts on this subject based on the ideXlab platform.
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Novel polyesteramide-based di- and triblock copolymers From thermo-mechanical properties to hydrolytic degradation
European Polymer Journal, 2011Co-Authors: Gaëlle Deshayes, Ingrid Verbruggen, Lise Trouillet-fonti, Franck Touraud, Rudolph Willem, Philippe Degée, Mathias Destarac, Etienne Fleury, Cécile Delcourt, Philippe DuboisAbstract:Two types of biodegradable poly(epsilon-caprolactone (CLo))-co-poly(epsilon caprolactam (CLa)) copolymers were prepared by catalyzed hydrolytic ring-opening polymerization For the first type of materials the respective cyclic comonomers were added simultaneously in the reaction medium leading to the formation of copolymers having a random distribution of co-units within the polyesteramide sequence as evidenced by H-1 and C-13 NMR For the second type of copolymers the cyclic comonomers were added sequentially in the reaction medium yielding diblock polyesteramides again evidenced by NMR The thermal and thermo-mechanical properties of the copolymers were investigated by DSC and DMA and correlated with the copolymer topology and composition The copolymers were char acterized by a storage modulus and alpha transition temperature intermediate to the modulus and T-g of the corresponding homopolymers The chemical composition and molecular weight of the copolymers proved to have only a limited effect on the thermo-mechanical properties of the materials The hydrolytic degradation of random copolymers was studied in a phosphate buffer at 60 degrees C and discussed in terms of chemical composition and molecular weight of the copolymers
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Activation of the hydrolytic polymerization of Epsilon-Caprolactam by ester functions: Straightforward route to aliphatic polyesteramides
Reactive and Functional Polymers, 2008Co-Authors: Gaëlle Deshayes, Ingrid Verbruggen, Lise Trouillet-fonti, Franck Touraud, Rudolph Willem, Philippe Degée, Mathias Destarac, Etienne Fleury, Cécile Delcourt, Philippe DuboisAbstract:The hydrolytic polymerization of ε-caprolactam (CLa) was carried out in bulk (in absence of solvent) at 250 °C in the presence of carboxylic esters and aqueous H3PO2. It turned out that by conducting the ring opening polymerization (ROP) of CLa in the presence of PEO-C(O)-O-C5H11, a selected model ester (PEO = poly(ethylene oxide)), a remarkable activating effect of the ester function on the hydrolytic polymerization of the lactam was observed yielding PEO-b-PCLa diblock copolymers. The comparison of the CLa monomer conversions obtained with or without the model ester activated by H3PO2, as determined by 1H NMR spectroscopy, has enabled to propose a multi-step mechanism in which three major reactions occurred: (i) ester and lactam hydrolysis, (ii) aminolysis of the carboxylic ester by the resulting primary amine of the hydrolyzed/opened lactam ring and (iii) condensation reactions between carboxylic acids and both amine/hydroxyl functions. The overall result of this multi-step mechanism can be assimilated as an “insertion” of the opened lactam into the ester function. By conducting the hydrolytic polymerization of CLa in the presence of an aliphatic polyester chain, such as poly(ε-caprolactone) (PCLo), polyesteramides were recovered with high yields and random distributions of the CLa and CLo repetitive units as determined by 13C NMR.
Mauro Boero - One of the best experts on this subject based on the ideXlab platform.
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hydrogen bond driven chemical reactions beckmann rearrangement of cyclohexanone oxime into epsilon caprolactam in supercritical water
Journal of the American Chemical Society, 2004Co-Authors: Mauro Boero, Tamio Ikeshoji, Chee Chin Liew, Kiyoyuki Terakura, Michele ParrinelloAbstract:Recent experiments have shown that supercritical water (SCW) has the ability to accelerate and make selective synthetic organic reactions, thus replacing the common but environmentally harmful acid and basic catalysts. In an attempt to understand the intimate mechanism behind this observation, we analyze, via first-principles molecular dynamics, the Beckmann rearrangement of cyclohexanone oxime into e-caprolactam in supercritical water, for which accurate experimental evidence has been reported. Differences in the wetting of the hydrophilic parts of the solute, enhanced by SCW, and the disrupted hydrogen bond network are shown to be crucial in triggering the reaction and in making it selective. Furthermore, the enhanced concentrations of H+ in SCW play an important role in starting the reaction.
R. Abdelhedi - One of the best experts on this subject based on the ideXlab platform.
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Polyamide from lactams by reactive rotational molding via anionic ring-opening polymerization: Optimization of processing parameters
Express Polymer Letters, 2013Co-Authors: Najoua Barhoumi, Abderrahim Maazouz, Mohamed Jaziri, R. AbdelhediAbstract:A reactive rotational molding (RRM) process was developed to obtain a PA6 by activated anionic ring-opening polymerization of Epsilon-Caprolactam (APA6). Sodium caprolactamate (C10) and caprolactam magnesium bromide (C1) were employed as catalysts, and difunctional hexamethylene-1,6-dicarbamoylcaprolactam (C20) was used as an activator. The kinetics of the anionic polymerization of Epsilon-Caprolactam into polyamide 6 was monitored through dynamic rheology and differential scanning calorimetry measurements. The effect of the processing parameters, such as the polymerization temperature, different catalyst/ activator combinations and concentrations, on the kinetics of polymerization is discussed. A temperature of 150 degrees C was demonstrated to be the most appropriate. It was also found that crystallization may occur during PA6 polymerization and that the combination C1/C20 was well suited as it permitted a suitable induction time. Isoviscosity curves were drawn in order to determine the available processing window for RRM. The properties of the obtained APA6 were compared with those of a conventionally rotomolded PA6. Results pointed at lower cycle times and increased tensile properties at weak deformation.