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S. Magnet - One of the best experts on this subject based on the ideXlab platform.
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amphiphilic gradient poly styrene co Acrylic Acid Copolymer prepared via nitroxide mediated solution polymerization synthesis characterization in aqueous solution and evaluation as emulsion polymerization stabilizer
Polymer, 2006Co-Authors: C. Lefay, B. Charleux, M. Save, C. Chassenieux, O. Guerret, S. MagnetAbstract:Abstract A well-defined, amphiphilic poly(styrene- co -Acrylic Acid) Copolymer was synthesized in a single step by nitroxide-mediated controlled free-radical Copolymerization of styrene and Acrylic Acid, without protection of the Acid groups: M n =6500 g mol −1 , M w / M n =1.5 and a composition of F AA =0.70±0.03 in Acrylic Acid. In addition to the good control over molar mass and molar mass distribution, the Copolymer exhibited a narrow composition distribution with a slight gradient. Such Copolymer was an efficient stabilizer for the emulsion polymerizations of styrene and of mixtures of methyl methacrylate and n -butyl acrylate, until 45 wt% solids. A low amount (typically 3–4 wt% based on the monomer(s)) was needed for a good stabilization. This is approximately a decade lower than the required amount of random, amphiphilic Copolymers prepared via conventional free-radical polymerization. The performances were, however, below those of analogous diblock Copolymers, but the great advantage is the very easy synthetic procedure.
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Amphiphilic gradient poly(styrene-co-Acrylic Acid) Copolymer prepared via nitroxide-mediated solution polymerization. Synthesis, characterization in aqueous solution and evaluation as emulsion polymerization stabilizer
Polymer, 2006Co-Authors: C. Lefay, B. Charleux, M. Save, C. Chassenieux, O. Guerret, S. MagnetAbstract:A well-defined, amphiphilic poly(styrene-co-Acrylic Acid) Copolymer was synthesized in a single step by nitroxide-mediated controlled free-radical Copolymerization of styrene and Acrylic Acid, without protection of the Acid groups: Mn=6500 g mol-1, Mw/Mn=1.5 and a composition of FAA=0.70±0.03 in Acrylic Acid. In addition to the good control over molar mass and molar mass distribution, the Copolymer exhibited a narrow composition distribution with a slight gradient. Such Copolymer was an efficient stabilizer for the emulsion polymerizations of styrene and of mixtures of methyl methacrylate and n-butyl acrylate, until 45 wt% solids. A low amount (typically 3-4 wt% based on the monomer(s)) was needed for a good stabilization. This is approximately a decade lower than the required amount of random, amphiphilic Copolymers prepared via conventional free-radical polymerization. The performances were, however, below those of analogous diblock Copolymers, but the great advantage is the very easy synthetic procedure. © 2006 Elsevier Ltd. All rights reserved.
Roberto Scaffaro - One of the best experts on this subject based on the ideXlab platform.
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On the Preparation and Characterization of Polyethylene/Polyamide Blends by Melt Processing in the Presence of an Ethylene/Acrylic Acid Copolymer and of New Phosphazene Compounds
Macromolecular Chemistry and Physics, 2006Co-Authors: Roberto Scaffaro, Francesco Paolo La Mantia, Maria Chiara Mistretta, Mario Gleria, Roberta Bertani, Filippo Samperi, Concetto PuglisiAbstract:Samples of HDPE and PA6 have been melt-processed in the presence of two new phosphazene compounds, CP-2EPOX and CP-20XA together with an ethylene/Acrylic Acid Copolymer. The blends have been prepared in an industrial twin-screw extruder by using PA6 and PE in weight ratios of 25/75 and 75/25. When used, 5 phr of EAA and 0.2 phr of CP have been added. The materials have been completely characterized from a rheological, morphological, and mechanical point of view. The results indicate that the additives used caused an increase in the rupture tensile properties, of the impact strength and viscosity especially in the PE-rich blend in the presence of CP-2EPOX. This result can be attributed both to a chain extension reaction on EAA and PA6 phases and on compatibilization effect due to the possible formation of EAA-g-PA6 Copolymers. This latter occurrence is suggested by an improved adhesion between the phases and by an increased turbidity observed in the Molau tests. Between the two compatibilizers, the CP-2EPOX displays the overall best results, especially for the PE-based blends.
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Reactive Compatibilization of PBT/EVA Blends with an Ethylene‐Acrylic Acid Copolymer and a Low Molar Mass Bis‐Oxazoline
Macromolecular Chemistry and Physics, 2004Co-Authors: Roberto Scaffaro, Francesco Paolo La Mantia, Claudia CastronovoAbstract:Polyesters and polyolefins form highly incompatible blends with poor properties and gross morphology that hinder any pratical applications. In this work, the possibility to compatibilize an incompatible blend of poly(butylene terephthalate) (PBT) with ethylene vinyl acetate (EVA) by adding a bis-oxazoline compound, 2,2'-(1,3-phenylene)-bis(2-oxazoline) (PBO), and an ethylene Acrylic Acid Copolymer (EAA) as comptabilizer precursors has been studied. The results indicate that the binary uncompatibilized blends show poor mechanical properties and a bad morphology with sarce adhesion between the phases. The situation is only slightly improved when the EEA is added while the best performance is achieved when quaternary PBT/EVA/EAA/PBO blends are prepared. In this latter case the elongation at break and the impact strength are doubled and the morphology is deeply improved. The formation of EAA-g-(PBO)-PBT Copolymers in the presence of PBO can be invoked to explain the results and it is demonstrated that the eventual chain extension of PBT or EAA is negligibel.
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reactive compatibilization of pa6 ldpe blends with an ethylene Acrylic Acid Copolymer and a low molar mass bis oxazoline
Polymer, 2003Co-Authors: Roberto Scaffaro, Francesco Paolo La Mantia, Loredana Canfora, Giovanni Polacco, Sara Filippi, Pierluigi MagagniniAbstract:Abstract A sample of polyamide-6 (PA) was blended with low density polyethylene (LDPE) in the 80/20 wt/wt ratio, either without and with 2 phr of an ethylene–Acrylic Acid Copolymer (EAA), Which was known to behave as a compatibilizer precursor, and the effect of the addition of small amounts (0.2 or 0.35 phr) of a fourth component, 2,2′-(1,3-phenylene)-bis(2-oxazoline) (PBO), was investigated. The reactions of PBO with EAA, PA and their blends were studied by recording as a function of time the torque applied to the blending apparatuses and by studying the solubility behavior of the products in formic Acid. The PALDPE blends were prepared in a co-rotating twin screw extruder and were characterized by Molau tests, differential scanning calorimetry, scanning electron microscopy, rheology, and determination of the ultimate mechanical properties, including impact tests. The results indicate that the effectiveness of EAA as a compatibilizer precursor is considerably enhanced when PBO is added into the blends. It is thought that the reactions of PBO with the free carboxyl groups of EAA and with the amine or carboxyl end groups of PA run, at least in part, toward the formation of PA- g -EAA Copolymers acting as the true compatibilizers for these blends.
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reactive compatibilization of pa6 ldpe blends with an ethylene Acrylic Acid Copolymer and a low molar mass bis oxazoline
Polymer, 2003Co-Authors: Roberto Scaffaro, Francesco Paolo La Mantia, Loredana Canfora, Giovanni Polacco, Sara Filippi, Pierluigi MagagniniAbstract:Abstract A sample of polyamide-6 (PA) was blended with low density polyethylene (LDPE) in the 80/20 wt/wt ratio, either without and with 2 phr of an ethylene–Acrylic Acid Copolymer (EAA), Which was known to behave as a compatibilizer precursor, and the effect of the addition of small amounts (0.2 or 0.35 phr) of a fourth component, 2,2′-(1,3-phenylene)-bis(2-oxazoline) (PBO), was investigated. The reactions of PBO with EAA, PA and their blends were studied by recording as a function of time the torque applied to the blending apparatuses and by studying the solubility behavior of the products in formic Acid. The PALDPE blends were prepared in a co-rotating twin screw extruder and were characterized by Molau tests, differential scanning calorimetry, scanning electron microscopy, rheology, and determination of the ultimate mechanical properties, including impact tests. The results indicate that the effectiveness of EAA as a compatibilizer precursor is considerably enhanced when PBO is added into the blends. It is thought that the reactions of PBO with the free carboxyl groups of EAA and with the amine or carboxyl end groups of PA run, at least in part, toward the formation of PA- g -EAA Copolymers acting as the true compatibilizers for these blends.
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Reactive compatibilization of PA6/LDPE blends with an ethylene -Acrylic Acid Copolymer and a low molar mass bis-oxazoline
Polymer, 2003Co-Authors: Roberto Scaffaro, Francesco Paolo La Mantia, Loredana Canfora, Giovanni Polacco, Sara Filippi, Pierluigi MagagniniAbstract:Abstract A sample of polyamide-6 (PA) was blended with low density polyethylene (LDPE) in the 80/20 wt/wt ratio, either without and with 2 phr of an ethylene–Acrylic Acid Copolymer (EAA), Which was known to behave as a compatibilizer precursor, and the effect of the addition of small amounts (0.2 or 0.35 phr) of a fourth component, 2,2′-(1,3-phenylene)-bis(2-oxazoline) (PBO), was investigated. The reactions of PBO with EAA, PA and their blends were studied by recording as a function of time the torque applied to the blending apparatuses and by studying the solubility behavior of the products in formic Acid. The PALDPE blends were prepared in a co-rotating twin screw extruder and were characterized by Molau tests, differential scanning calorimetry, scanning electron microscopy, rheology, and determination of the ultimate mechanical properties, including impact tests. The results indicate that the effectiveness of EAA as a compatibilizer precursor is considerably enhanced when PBO is added into the blends. It is thought that the reactions of PBO with the free carboxyl groups of EAA and with the amine or carboxyl end groups of PA run, at least in part, toward the formation of PA- g -EAA Copolymers acting as the true compatibilizers for these blends.
R Pelech - One of the best experts on this subject based on the ideXlab platform.
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thermal degradation of butyl acrylate methyl acrylate Acrylic Acid Copolymers
Journal of Thermal Analysis and Calorimetry, 2009Co-Authors: Zbigniew Czech, R PelechAbstract:The thermal degradation of Copolymers based on butyl acrylate-methyl acrylate-Acrylic Acid used as Acrylic pressure-sensitive adhesives, especially for bonding of plasticizer containing materials, has been investigated using thermogravimetry and pyrolysis-gas chromatography at 250°C. It was observed that during the pyrolysis of butyl acrylate-methyl acrylate-Acrylic Acid Copolymers unsaturated monomers as methyl acrylate, methyl methacrylate, butyl acrylate and butyl methacrylate were formed. During the side-chain butyl acrylate-methyl-acrylate-Acrylic Acid-Copolymer degradation the presence of methyl alcohol and butyl alcohol was observed.
C. Lefay - One of the best experts on this subject based on the ideXlab platform.
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amphiphilic gradient poly styrene co Acrylic Acid Copolymer prepared via nitroxide mediated solution polymerization synthesis characterization in aqueous solution and evaluation as emulsion polymerization stabilizer
Polymer, 2006Co-Authors: C. Lefay, B. Charleux, M. Save, C. Chassenieux, O. Guerret, S. MagnetAbstract:Abstract A well-defined, amphiphilic poly(styrene- co -Acrylic Acid) Copolymer was synthesized in a single step by nitroxide-mediated controlled free-radical Copolymerization of styrene and Acrylic Acid, without protection of the Acid groups: M n =6500 g mol −1 , M w / M n =1.5 and a composition of F AA =0.70±0.03 in Acrylic Acid. In addition to the good control over molar mass and molar mass distribution, the Copolymer exhibited a narrow composition distribution with a slight gradient. Such Copolymer was an efficient stabilizer for the emulsion polymerizations of styrene and of mixtures of methyl methacrylate and n -butyl acrylate, until 45 wt% solids. A low amount (typically 3–4 wt% based on the monomer(s)) was needed for a good stabilization. This is approximately a decade lower than the required amount of random, amphiphilic Copolymers prepared via conventional free-radical polymerization. The performances were, however, below those of analogous diblock Copolymers, but the great advantage is the very easy synthetic procedure.
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Amphiphilic gradient poly(styrene-co-Acrylic Acid) Copolymer prepared via nitroxide-mediated solution polymerization. Synthesis, characterization in aqueous solution and evaluation as emulsion polymerization stabilizer
Polymer, 2006Co-Authors: C. Lefay, B. Charleux, M. Save, C. Chassenieux, O. Guerret, S. MagnetAbstract:A well-defined, amphiphilic poly(styrene-co-Acrylic Acid) Copolymer was synthesized in a single step by nitroxide-mediated controlled free-radical Copolymerization of styrene and Acrylic Acid, without protection of the Acid groups: Mn=6500 g mol-1, Mw/Mn=1.5 and a composition of FAA=0.70±0.03 in Acrylic Acid. In addition to the good control over molar mass and molar mass distribution, the Copolymer exhibited a narrow composition distribution with a slight gradient. Such Copolymer was an efficient stabilizer for the emulsion polymerizations of styrene and of mixtures of methyl methacrylate and n-butyl acrylate, until 45 wt% solids. A low amount (typically 3-4 wt% based on the monomer(s)) was needed for a good stabilization. This is approximately a decade lower than the required amount of random, amphiphilic Copolymers prepared via conventional free-radical polymerization. The performances were, however, below those of analogous diblock Copolymers, but the great advantage is the very easy synthetic procedure. © 2006 Elsevier Ltd. All rights reserved.
A R Solymani - One of the best experts on this subject based on the ideXlab platform.
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sono assisted photocatalytic degradation of styrene Acrylic Acid Copolymer in aqueous media with nano titania particles and kinetic studies
Journal of Hazardous Materials, 2010Co-Authors: Javad Saien, H Delavari, A R SolymaniAbstract:The ultrasonic irradiation (28 kHz, 50 W) in pre-cavitations regime was employed to enhance the degradation rate of styrene-Acrylic Acid Copolymer in aqueous media with nano titania photocatalyst particles. A stainless steel cylindrical sono-photo reactor with capacity of about 1.25 L, equipped with a UV lamp (250 W) was used. The influence of operational parameters, i.e. catalyst concentration, pH and temperature was studied and the role of active species was also distinguished. For an initial substrate concentration of 30 mg L(-1), under mild applied conditions of 30 mg L(-1) of photocatalyst, 25 degrees C and natural pH, a degradation and mineralization conversion of 96% and 91%, respectively, was achieved using sono-assisted photocatalysis process in about only 60 min. These efficiencies are much higher than those obtained with only photocatalysis process. Meanwhile, the threshold of cavitations was found corresponded to catalyst concentration of about 70 mg L(-1). Kinetic studies based on Langmuir-Hinshelwood and power law models in addition to the results from radical scavenger usage revealed that for sono-assisted process, the substrate undergoes degradation mainly via electron-hole redox on the surface of titania particles. It is while for the only photocatalysis process, the reaction proceeds via hydroxyl radicals in the solution bulk.