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Polymers, paint and wood industries, Polymères, industries des peintures et bois, Sciences exactes et technologie, Exact sciences and technology, Chimie, Chemistry, Chimie analytique, Analytical chemistry, Méthodes chromatographiques et méthodes physiques associées à la chromatographie, Chromatographic methods and physical methods associated with chromatography, Autres méthodes chromatographiques, Other chromatographic methods, Sciences appliquees, Applied sciences, Industrie des polymeres, peintures, bois, Polymer industry, paints, wood, Technologie des polymères, Technology of polymers, Formes d'application et semiproduits, Forms of application and semi-finished materials, Matériaux composites, Composites, Acrylamide dérivé polymère, Acrylamide derivative polymer, Acrilamida derivado polímero, Agent accrochage, Coupling agent, Agente enganche, Chromatographie HPLC, HPLC chromatography, Cromatografía HPLC, Cinétique, Kinetics, Cinética, Dérivé du naphtalène, Naphthalene derivatives, Naftaleno derivado, Effet température, Temperature effect, Efecto temperatura, Etude expérimentale, Experimental study, Estudio experimental, Particule composite, Composite particles, Phase stationnaire, Stationary phase, Fase estacionaria, Polymère greffé, Graft polymers, Polymérisation radicalaire, Free radical polymerization, Polimerización radicalar, Préparation, Preparation, Preparación, Réaction surface, Surface reaction, Reacción superficie, Silane organique, Organic silane, Silano orgánico, Silice, Silica, Sílice, Séparation, Separation, Separación, Traitement surface, Surface treatment, Tratamiento superficie, Transition phase, Phase transitions, Transición fase, Utilisation, Use, Uso, and Acrylamide(N-isopropyl) polymère

In this study thermosensitive composites were prepared through grafting copolymerization of N-isopropylacrylamide (NIPAM) with [3-(methacryloyloxy) propyl] trimethoxysilane (MOPT, a silicon coupling agent) coupled on the surface of ultrafine silica beads. The effects of some synthetic conditions such as stabilizers, solvents, initiator, feed ratio on the grafting yields were investigated. The structures of the composites were characterized by infrared spectra, differential scanning calorimetry, and scanning electron microscope. The thermosensitive composite was used as a packing material in high performance liquid chromatography for separating naphthalene derivatives. The result indicated that satisfactory separation was achieved by controlling temperature of the column. As a comparison the packing material of silica-MOPT has no this separating efficiency due to absence of thermosensitivety. The mechanism for the temperature-controlled separation is attributed to polarity change of the poly(N-isopropylacrylamide) (PNIPAM) on silica surface when PNIPAM undergoes volume phase transition.

Polymers, paint and wood industries, Polymères, industries des peintures et bois, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Industrie des polymeres, peintures, bois, Polymer industry, paints, wood, Technologie des polymères, Technology of polymers, Formes d'application et semiproduits, Forms of application and semi-finished materials, Matériaux composites, Composites, Conductivité électrique, Electrical conductivity, Conductividad eléctrica, Constante diélectrique, Permittivity, Constante dieléctrica, Effet concentration, Concentration effect, Efecto concentración, Etude expérimentale, Experimental study, Estudio experimental, Imide polymère, Polyimide, Imida polímero, Matériau composite, Composite material, Material compuesto, Matériau renforcé dispersion, Dispersion reinforced material, Material renforzado dispersión, Nanocomposite, Nanocompuesto, Nanotube carbone, Carbon nanotubes, Nanotube multifeuillets, Multiwalled nanotube, Oxydation, Oxidation, Oxidación, Polycondensation solution, Solution polycondensation, Policondensación solución, Propriété diélectrique, Dielectric properties, Propiedad dieléctrica, Propriété mécanique, Mechanical properties, Propiedad mecánica, Propriété thermique, Thermal properties, Propiedad térmica, Propriété électrique, Electrical properties, Propiedad eléctrica, Préparation, Preparation, Preparación, Résistance traction, Tensile strength, Resistencia tracción, Stabilité thermique, Thermal stability, Estabilidad térmica, Traitement surface, Surface treatment, and Tratamiento superficie

Polyimide/multi-walled carbon nanotube (PI-MWNT) nanocomposites were fabricated by an in situ polymerization process. Chemical compatibility between the PI matrix and MWNTs is achieved by pretreatment of the carbon nanotubes in a mixture of sulfuric acid and nitric acid. The dispersion of MWNTs in the PI matrix was found to be enhanced significantly after acid modification. The glass transition (Tg) and decomposition (Td) temperature of PI-MWNT nanocomposites were improved as the MWNT content increased from 0.5 to 15 wt%. The storage modulus of the PI/MWNT nanocomposites is nine times higher than that of pristine PI at room temperature. The tensile strength of PI doubles when 7 wt% MWNTs is added. The dielectric constant of the PI-MWNT nanocomposites increased from 3.5 to 80 (1 kHz) as the MWNT content increased to 15 wt%. The present study demonstrates that enhanced mechanical properties can be obtained through a simple in-situ polymerization process.

Polymers, paint and wood industries, Polymères, industries des peintures et bois, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Industrie des polymeres, peintures, bois, Polymer industry, paints, wood, Technologie des polymères, Technology of polymers, Formes d'application et semiproduits, Forms of application and semi-finished materials, Matériaux composites, Composites, Agent intercalant, Intercalating agent, Agente intercalante, Argile, Clay, Arcilla, Caoutchouc thermoplastique, Thermoplastic rubber, Caucho termoplástico, Composé de l'ammonium quaternaire, Quaternary ammonium compound, Amonio cuaternario compuesto, Degré dispersion, Dispersion degree, Grado dispersión, Effet concentration, Concentration effect, Efecto concentración, Etude expérimentale, Experimental study, Estudio experimental, Matériau composite, Composite material, Material compuesto, Matériau renforcé dispersion, Dispersion reinforced material, Material renforzado dispersión, Montmorillonite, Montmorilonita, Morphologie, Morphology, Morfología, Nanocomposite, Nanocompuesto, Propriété mécanique, Mechanical properties, Propiedad mecánica, Résistance déchirement, Tear strength, Resistencia a la desgarradura, Résistance traction, Tensile strength, Resistencia tracción, Traitement surface, Surface treatment, Tratamiento superficie, Uréthanne élastomère, Polyurethane elastomer, Uretano elastómero, and Mélangeage état fondu

The intercalated thermoplastic polyurethane (TPU)/ montmorillonite (MMT) nanocomposites were prepared by melt blending TPU and organic octadecylammonium-treated MMT (ODA-MMT) at 150-155°C for 10 min. Compared with those of TPU/montmorillonite composites, the interface interaction and dispersion of TPU/ ODA-MMT nanocomposites were improved remarkably. The tensile strength and tear strength of the TPU/ ODA-MMT nanocomposites were higher than those of pure TPU, and the MMT platelets dispersed on the nanometer scale in TPU matrix had reinforce effect. Due to the labyrinth effect of the MMT platelets dispersed on the nanometer scale in the TPU matrix caused by the eximious barrier and strong interaction between the MMT platelets and TPU, the temperature of initial weight loss of the TPU/ODA-MMT nanocomposites was higher than that of pure TPU and TPU/ MMT composites in the second thermodegradation step.

Polymers, paint and wood industries, Polymères, industries des peintures et bois, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Industrie des polymeres, peintures, bois, Polymer industry, paints, wood, Technologie des polymères, Technology of polymers, Formes d'application et semiproduits, Forms of application and semi-finished materials, Matériaux composites, Composites, Agent accrochage, Coupling agent, Agente enganche, Effet concentration, Concentration effect, Efecto concentración, Ester polymère, Ester polymer, Ester polímero, Etude expérimentale, Experimental study, Estudio experimental, Fibre naturelle, Natural fiber, Fibra natural, Fibre végétale, Plant fiber, Fibra vegetal, Frottement glissement, Sliding friction, Frotamiento deslizamiento, Matériau composite, Composite material, Material compuesto, Matériau renforcé dispersion, Dispersion reinforced material, Material renforzado dispersión, Mécanisme usure, Wear mechanisms, Mecanismo desgaste, Propriété mécanique, Mechanical properties, Propiedad mecánica, Résistance usure, Wear resistance, Resistencia al desgaste, Silane organique, Organic silane, Silano orgánico, Sisal, Traitement surface, Surface treatment, Tratamiento superficie, Tribologie, Tribology, Tribología, Usure glissement, Sliding wear, Desgaste deslizamiento, and Fibre coupée

Chopped sisal fibre-reinforced polyester composites with and without silane modification were prepared. Wear and friction measurements on the chopped sisal fibre reinforced polyester composites have been performed at different loads for different weight percentages of sisal fibre by using a pin-on-disc wear and friction tester. It has been found that increase of chopped sisal fibre content increased the Pressure-Velocity (PV) limit of composites. Silane modification improved the wear resistance of untreated sisal fibre reinforced polyester composite. Coefficient of friction increased with increase of fibre content and decreased with increase of load. Wear mechanism has been discussed with the help of SEM observations.

Polymers, paint and wood industries, Polymères, industries des peintures et bois, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Industrie des polymeres, peintures, bois, Polymer industry, paints, wood, Technologie des polymères, Technology of polymers, Formes d'application et semiproduits, Forms of application and semi-finished materials, Matériaux composites, Composites, Acétylation, Acetylation, Acetilación, Agent accrochage, Coupling agent, Agente enganche, Base chimique, Chemical base, Base química, Etude expérimentale, Experimental study, Estudio experimental, Fibre naturelle, Natural fiber, Fibra natural, Fibre végétale, Plant fiber, Fibra vegetal, Matériau composite, Composite material, Material compuesto, Matériau renforcé fibre, Fiber reinforced material, Material reforzado fibra, Modification chimique, Chemical modification, Modificación química, Morphologie, Morphology, Morfología, Polymère, Polymer, Polímero, Propriété mécanique, Mechanical properties, Propiedad mecánica, Relation mise en oeuvre propriété, Property processing relationship, Relación puesta en marcha propiedad, Silane organique, Organic silane, Silano orgánico, Traitement surface, Surface treatment, Tratamiento superficie, and Biocomposite

A critical review of the literature on the various aspects of natural fibers and biocomposites with a particular reference to chemical modifications is presented in this paper. A notable disadvantage of natural fibers is their polarity which makes it incompatible with hydrophobic matrix. This incompatibility results in poor interfacial bonding between the fibers and the matrix. This in turn leads to impaired mechanical properties of the composites. This defect can be remedied by chemical modification of fibers so as to make it less hydrophilic. This paper reviews the latest trends in chemical modifications and characterizations of natural fibers. The structure and properties of natural fibers have been discussed. Common chemical modifications and their mechanisms have also been elaborated. The importance of chemical modifications and the resultant enhancement in the properties of the composites have also been reviewed. Recent investigations dealing with chemical modifications of natural fiber-reinforced composites have also been cited.

Polymers, paint and wood industries, Polymères, industries des peintures et bois, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Industrie des polymeres, peintures, bois, Polymer industry, paints, wood, Technologie des polymères, Technology of polymers, Formes d'application et semiproduits, Forms of application and semi-finished materials, Matériaux composites, Composites, Agent intercalant, Intercalating agent, Agente intercalante, Argile organique, Organic clay, Arcilla orgánica, Argile, Clay, Arcilla, Composé de l'ammonium quaternaire, Quaternary ammonium compound, Amonio cuaternario compuesto, Degré dispersion, Dispersion degree, Grado dispersión, Etude expérimentale, Experimental study, Estudio experimental, Matériau composite, Composite material, Material compuesto, Matériau renforcé dispersion, Dispersion reinforced material, Material renforzado dispersión, Montmorillonite, Montmorilonita, Morphologie, Morphology, Morfología, Nanocomposite, Nanocompuesto, Polymérisation radicalaire, Free radical polymerization, Polimerización radicalar, Polymérisation suspension, Suspension polymerization, Polimerización suspensión, Polymérisation émulsion, Emulsion polymerization, Polimerización emulsión, Propriété thermique, Thermal properties, Propiedad térmica, Préparation, Preparation, Preparación, Relation mise en oeuvre propriété, Property processing relationship, Relación puesta en marcha propiedad, Relation mise en oeuvre structure, Structure processing relationship, Relación puesta en marcha estructura, Stabilité thermique, Thermal stability, Estabilidad térmica, Styrène polymère, Styrene polymer, Estireno polímero, Traitement surface, Surface treatment, and Tratamiento superficie

Organophilic montmorillonite was prepared using ionexchange method between sodium ions in clay layers and four kind of quaternary ammonium salt. The montmorillonite has the largest d001-spacing, as determined by X-ray diffraction in modified by di(hydrogenated tallowalkyl) dimethyl ammonium chloride. Polystyrene montmorillonite nanocomposites were obtained by suspension and emulsion polymerization of styrene in the dispersed organophilic montmorillonite. The d001-spacing of clay was determined by X-ray diffraction (XRD). The thermal stability of organophilic montmorillonite was investigated by thermogravimetric analysis (TGA).

Polymers, paint and wood industries, Polymères, industries des peintures et bois, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Industrie des polymeres, peintures, bois, Polymer industry, paints, wood, Technologie des polymères, Technology of polymers, Formes d'application et semiproduits, Forms of application and semi-finished materials, Matériaux composites, Composites, Agent accrochage, Coupling agent, Agente enganche, Agent intercalant, Intercalating agent, Agente intercalante, Argile organique, Organic clay, Arcilla orgánica, Argile, Clay, Arcilla, Composé de l'ammonium quaternaire, Quaternary ammonium compound, Amonio cuaternario compuesto, Cristallinité, Crystallinity, Cristalinidad, Degré dispersion, Dispersion degree, Grado dispersión, Etude expérimentale, Experimental study, Estudio experimental, Matériau composite, Composite material, Material compuesto, Matériau renforcé dispersion, Dispersion reinforced material, Material renforzado dispersión, Montmorillonite, Montmorilonita, Morphologie, Morphology, Morfología, Nanocomposite, Nanocompuesto, Oléfine polymère, Olefin polymer, Olefina polímero, Propriété mécanique, Mechanical properties, Propiedad mecánica, Propriété rhéologique, Rheological properties, Propiedad reológica, Propriété thermique, Thermal properties, Propiedad térmica, Propène polymère, Propylene polymer, Propeno polímero, Réaction état solide, Solid state reaction, Reacción estado sólido, Silane organique, Organic silane, Silano orgánico, Stabilité thermique, Thermal stability, Estabilidad térmica, Traitement surface, Surface treatment, Tratamiento superficie, and Mélangeage état fondu

A novel organomodified montmorillonite prepared by solid-state method and its nanocomposites with polypropylene were studied. The interaction between modifying agent and montmorillonite was investigated by X-ray diffraction (XRD) analysis, contact angle determination, and Fourier-transform infrared spectroscopy. The results showed that the modifying agent behaves as an effective intercalating agent, enlarging the interlayer spacing of montmorillonite and making montmorillonite more hydrophobic. Polypropylene/solid-state organomodified montmorillonite composites were prepared by melt-mixing method. The dispersion of the silicates was investigated by XRD analysis and transmission electron microscopy. It was found that the nanocomposites are formed with solid-state organomodified montmorillonite and polypropylene. The thermogravimetric analysis and differential scanning calorimetry results showed that the organoclay could enhance the thermal stability and decrease the relative crystallinity of polypropylene. Mechanical and rheological tests indicated that the organoclay improves the mechanical properties but has no obvious effect on rheological properties of polypropylene.

Polymers, paint and wood industries, Polymères, industries des peintures et bois, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Industrie des polymeres, peintures, bois, Polymer industry, paints, wood, Technologie des polymères, Technology of polymers, Formes d'application et semiproduits, Forms of application and semi-finished materials, Matériaux composites, Composites, Acide gras, Fatty acids, Acido graso, Carbonate de calcium, Calcium carbonate, Calcio carbonato, Distribution dimension particule, Particle size distribution, Distribución dimensión partícula, Effet concentration, Concentration effect, Efecto concentración, Etude expérimentale, Experimental study, Estudio experimental, Interaction matière charge polymère, Polymer filler interaction, Interacción materia carga polímero, Matériau composite, Composite material, Material compuesto, Matériau renforcé dispersion, Dispersion reinforced material, Material renforzado dispersión, Module élasticité, Elastic modulus, Módulo elasticidad, Perte mécanique, Mechanical loss, Pérdida mecánica, Propriété dynamomécanique, Dynamic mechanical properties, Propiedad dinamomecánica, Propriété mécanique, Mechanical properties, Propiedad mecánica, Propriété traction, Tensile property, Propiedad tracción, Relation mise en oeuvre propriété, Property processing relationship, Relación puesta en marcha propiedad, Réticulation, Crosslinking, Reticulación, Siloxane(diméthyl) polymère, Dimethylsiloxane polymer, Siloxano(dimetil) polímero, Traitement surface, Surface treatment, Tratamiento superficie, and Composite dentaire

The mechanical behavior of poly(di-methyl siloxane) (PDMS) composites containing high volume fractions of natural CaCO3 particles of various particle size distributions was studied under tensile and oscillatory bending stresses, emphasizing the unique behavior of high filler loaded compositions. Composites containing the maximal possible solid loading of raw CaCO3 were investigated for the effect of fatty acids surface treatment. The elastic modulus increased with increasing filler loading, following Chantler's model for dental composites when correlated with the absolute filler volume fraction. Good fit to traditional models, e.g., Frankle-Acrivos and Halpin-Tsai, was obtained by correlating the modulus values with the volume fraction relative to the maximal possible filler loading. A master curve of different particle size distributions and filler levels composites was obtained by using the relative volume fraction values, illustrating the effect of particle packing characteristics on small deformation mechanical behavior. A minor increase in Tg was found in parallel to the appearance of a Tm relaxation peak at approximately -40°C. A peak temperature shift at Tm and a pronounced increase in this peak with increasing filler fraction was found as well. The changes in the melting transition are attributed to the constraints of the filler particles acting on the crosslinked melting polymer. Surface treatment with fatty acids significantly degraded the tensile properties. Interestingly, an increase of 4 vol% filler was enabled owing to the surface treatment, while restoring reasonable tensile properties. No significant effect was observed for excess of fatty acids resulting from physically adsorbed acids. Tan δ curves reveal low PDMS-CaCO3 particles interactions, and mobility of the PDMS chains in the increased filler fraction as in the treated 64 vol% composite, both higher than those in the raw composite.

Energy, Énergie, Environment, Environnement, Pollution, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Pollution, Pollution atmosphérique, Atmospheric pollution, Généralités, General, Emission polluant, Pollutant emission, Emisión contaminante, Polluant, Pollutant, Contaminante, Pollution air, Air pollution, Contaminación aire, Traceur, Tracers, Trazador, Traitement surface, Surface treatment, Tratamiento superficie, Ventilation, Ventilación, capture efficiency, industrial ventilation, lateral exhaust ventilation, open surface tank ventilation, smoke visualization, and tracer gas

In a local exhaust ventilation system, where the pollutant or the emitted flows are captured near the generated source, the knowledge of the capture efficiency is necessary to evaluate performance. This article reports a study of the influence of the exhaust hood slot height on the capture efficiency. For this study, the emission of gases and vapors from open surface tanks used in industrial treatments has been simulated in an installation fitted with two ventilation systems: lateral exhaust and push-pull. Several configurations were possible by varying the geometrical and operational conditions. Both qualitative and quantitative evaluations have been performed, the former through observations of the flows using smoke and the latter by using sulfur hexafluoride as tracer gas. The results obtained on capture efficiency for both ventilation systems tested with several exhaust slot height and as a function of the operating flows rates, are presented. It was found that varying the exhaust slot height between 15 and 45 cm had no effect on capture efficiency. The results show that there are no significant differences between the exhaust slots heights tested, although, in the case of 60 cm for lateral exhaust ventilation, the efficiency was slightly lower.

Polymers, paint and wood industries, Polymères, industries des peintures et bois, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Industrie des polymeres, peintures, bois, Polymer industry, paints, wood, Technologie des polymères, Technology of polymers, Formes d'application et semiproduits, Forms of application and semi-finished materials, Matériaux composites, Composites, Absorption eau, Water absorption, Absorción agua, Agent accrochage, Coupling agent, Agente enganche, Bagasse, Bagazo, Etude expérimentale, Experimental study, Estudio experimental, Fibre naturelle, Natural fiber, Fibra natural, Fibre végétale, Plant fiber, Fibra vegetal, Matériau composite, Composite material, Material compuesto, Matériau renforcé fibre, Fiber reinforced material, Material reforzado fibra, Morphologie, Morphology, Morfología, Oléfine polymère, Olefin polymer, Olefina polímero, Propriété mécanique, Mechanical properties, Propiedad mecánica, Propriété rhéologique, Rheological properties, Propiedad reológica, Propène polymère, Propylene polymer, Propeno polímero, Relation mise en oeuvre propriété, Property processing relationship, Relación puesta en marcha propiedad, Résistance traction, Tensile strength, Resistencia tracción, Silane organique, Organic silane, Silano orgánico, Traitement surface, Surface treatment, Tratamiento superficie, Viscosité, Viscosity, Viscosidad, Silane(3-glycidyloxypropyl triéthoxy), and Silane(triméthoxy vinyl)

Polypropylene/bagasse fiber composites were prepared by compounding polypropylene (PP) with bagasse fibers as reinforcing filler. Surfaces of fibers were modified through the use of silane coupling agents (Vinyltrimethoxysilane and y-Glycidoxypropyltrimethoxysilane). The fiber coating was performed by mixing of silane with fibers and cured through microwave oven in presence of catalyst. It was found that modification of surface fiber will change the physical, mechanical, morphological, and rheological properties of composite. It was observed from scanning electron microscopy that fiber adhesion to matrix has been improved and so as dispersion. Addition of fibers increases the melt viscosity in unmodified fibers but reduced the melt viscosity for modified fibers and even the viscosity is lower at higher loading compared with unmodified fibers. The tensile strength and tensile modulus increased in modified fibers compared with the unmodified on the same loading, but elongation at break decreased. The effect of coupling agent on properties of filled PP depend on the content of coupling agents and optimum amount was achieve through measurement of water absorption. Two types of coupling agents were used, one as A-171 [CH2=CHSi (OCH3)3] and second one as A-187 [CH2OCHCH2O (CH2)3Si(OCH3)], the first one shows better adhesion to the fibers and improvements in mechanical properties are much better compared with the second one.

Polymers, paint and wood industries, Polymères, industries des peintures et bois, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Industrie des polymeres, peintures, bois, Polymer industry, paints, wood, Technologie des polymères, Technology of polymers, Formes d'application et semiproduits, Forms of application and semi-finished materials, Matériaux composites, Composites, Absorption eau, Water absorption, Absorción agua, Acide chlorhydrique, Hydrochloric acid, Ácido chlorhídrico, Acrylique acide polymère, Acrylic acid polymer, Acrílico ácido polímero, Argile, Clay, Arcilla, Attapulgite, Atapuljita, Etude expérimentale, Experimental study, Estudio experimental, Matériau absorbant, Absorbent material, Material absorbente, Matériau composite, Composite material, Material compuesto, Polymère réticulé, Crosslinked polymer, Polímero reticulado, Polyélectrolyte, Polyelectrolyte, Polielectrolito, Pouvoir absorbant, Absorptivity, Poder absorción, Relation mise en oeuvre propriété, Property processing relationship, Relación puesta en marcha propiedad, Traitement chimique, Chemical treatment, Tratamiento químico, Traitement surface, Surface treatment, Tratamiento superficie, Traitement thermique, Heat treatment, Tratamiento térmico, and Superabsorbant

The effect of acid activation and thermal treatment of attapulgite on water absorbency of superabsorbent composite were investigated. Under the same preparation conditions, superabsorbent composite prepared with natural attapulgite exhibited a water absorbency of 639 g/g and it merely kept 71% of its initial water absorbency after 5 times of swelling-deswelling-reswelling test. However, superabsorbent composites prepared with 2-10 M hydrochloric acid acidified attapulgite and 100-400°C thermal treated attapulgite respectively exhibited the water absorbency of 884-1,241 g/g and 701-1,515 g/g. Also, those superabsorbent composites can keep 87% and 85% of their initial water absorbency after 5 times of swelling-deswelling-reswelling test, respectively. These results showed that, compared with superabsorbent composite prepared with natural attapulgite, the comprehensive water-absorbing properties of poly(acrylic acid)/ attapulgite superabsorbent composites were improved effectively by acid activation and thermal treatment of attapulgite. This improvement of water absorbencies and gel strength of superabsorbent composite may be due to synthetical factors such as changes in the crystalline structure and the specific surface area and improvement of the number and the activity of hydroxyl groups of attapulgite, which in turn influence the grafting efficiency of monomer, crosslinking density, and the structure of superabsorbent composite network.

Polymers, paint and wood industries, Polymères, industries des peintures et bois, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Industrie des polymeres, peintures, bois, Polymer industry, paints, wood, Technologie des polymères, Technology of polymers, Formes d'application et semiproduits, Forms of application and semi-finished materials, Matériaux composites, Composites, Agent surface polymère, Surfactant polymer, Agente superficie polímero, Agent surface, Surfactant, Agente superficie, Degré dispersion, Dispersion degree, Grado dispersión, Etude expérimentale, Experimental study, Estudio experimental, Matériau composite, Composite material, Material compuesto, Matériau renforcé dispersion, Dispersion reinforced material, Material renforzado dispersión, Morphologie, Morphology, Morfología, Mélangeage, Mixing, Mezclado, Nanocomposite, Nanocompuesto, Particule enrobée, Coated particle, Partícula envuelta, Presse extrusion double vis, Double screw extruder, Prensa extrusión doble tornillo, Propriété mécanique, Mechanical properties, Propiedad mecánica, Propriété traction, Tensile property, Propiedad tracción, Relation mise en oeuvre propriété, Property processing relationship, Relación puesta en marcha propiedad, Relation mise en oeuvre structure, Structure processing relationship, Relación puesta en marcha estructura, Résistance choc, Impact strength, Resistencia choque, Stabilité photochimique, Photochemical stability, Estabilidad fotoquímica, Styrène polymère, Styrene polymer, Estireno polímero, Titane IV Oxyde, Titanium IV Oxides, Titanio IV Óxido, Traitement surface, Surface treatment, Tratamiento superficie, and Presse extrusion double vis co-rotative

This article presents the study of melt compounding of polystyrene (PS) with various types of titanium dioxide (TiO2) nanoparticles and surfactants, using a corotating twin screw extruder with multiple screw element configurations. It was found that a properly designed high shear screw configuration and the copolymer of silicone, ethylene oxide, and propylene oxide-based surfactant produced the greatest degree of nanoparticle dispersion in PS/TiO2 nanocomposites, whereas a silane-based surfactant and silicon dioxide (SiO)2 or aluminum oxide (Al2O3) coated TiO2 nanoparticles yielded nanocomposites with the least photocatalytic degradation effects and the best retention of tensile and impact properties.

Polymers, paint and wood industries, Polymères, industries des peintures et bois, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Industrie des polymeres, peintures, bois, Polymer industry, paints, wood, Technologie des polymères, Technology of polymers, Formes d'application et semiproduits, Forms of application and semi-finished materials, Matériaux composites, Composites, Argile organique, Organic clay, Arcilla orgánica, Composé de l'ammonium quaternaire, Quaternary ammonium compound, Amonio cuaternario compuesto, Durcissement (matière plastique), Curing (plastics), Endurecimiento (material plástico), Echange cation, Cation exchange, Cambio catiónico, Effet concentration, Concentration effect, Efecto concentración, Etude expérimentale, Experimental study, Estudio experimental, Matériau composite, Composite material, Material compuesto, Matériau renforcé fibre, Fiber reinforced material, Material reforzado fibra, Matériau transparent, Transparent material, Material transparente, Mica, Morphologie, Morphology, Morfología, Nanocomposite, Nanocompuesto, Propriété dynamomécanique, Dynamic mechanical properties, Propiedad dinamomecánica, Propriété thermique, Thermal properties, Propiedad térmica, Renforcement mécanique, Strengthening, Refuerzo mecánico, Résine phénolique, Phenolic resin, Resina fenólica, Stabilité thermique, Thermal stability, Estabilidad térmica, Traitement surface, Surface treatment, and Tratamiento superficie

Novel polybenzoxazine-clay hybrids were prepared by the in situ polymerization of the typical benzoxazine monomer, bis(3-phenyl-3,4-dihydro-2H-1,3-benzoxazinyl)isopropane (B-a) in the presence of aminolauric acid-modified mica (ALA-mica). Various ratios of ALA-mica were dispersed into solutions of B-a in N,N-dimethylacetamide, followed by casting into film form. The hybrids were thermally cured up to 230°C, affording transparent nanocomposite films up to 10 wt% of mica loadings. The cure behavior was monitored by both IR and differential scanning calorimetry, indicating the catalytic effect of the modified mica. The morphology of the nanocomposites was studied by XRD, showing a featureless pattern, which suggests the disordered dispersion of mica into polybenzoxazine matrix. The dynamic mechanical properties of some hybrids show that the nanocomposites have higher storage modulus over the whole temperature range than the neat polybenzoxazine. Thermogravimetric analysis results confirmed that the thermal stability and char yield of polybenzoxazine resin increased apparently by hybridization with mica corresponding to the mica content.

Polymers, paint and wood industries, Polymères, industries des peintures et bois, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Industrie des polymeres, peintures, bois, Polymer industry, paints, wood, Technologie des polymères, Technology of polymers, Formes d'application et semiproduits, Forms of application and semi-finished materials, Matériaux composites, Composites, Coefficient dilatation thermique, Thermal expansion coefficient, Coeficiente dilatación térmica, Dérivé de l'aniline, Aniline derivatives, Anilina derivado, Effet concentration, Concentration effect, Efecto concentración, Epoxyde résine, Epoxy resin, Epóxido resina, Etude expérimentale, Experimental study, Estudio experimental, Fibre graphite, Graphite fiber, Fibra grafito, Fibre minérale, Mineral fiber, Fibra inorgánica, Fonctionnalisation, Functionalization, Funciónalización, Matériau composite, Composite material, Material compuesto, Matériau renforcé dispersion, Dispersion reinforced material, Material renforzado dispersión, Nanocomposite, Nanocompuesto, Propriété mécanique, Mechanical properties, Propiedad mecánica, Propriété thermique, Thermal properties, Propiedad térmica, Résistance flexion, Bending strength, Resistencia flexión, Traitement surface, Surface treatment, Tratamiento superficie, and Nanofibre carbone

Our previous studies showed that herringbone graphitic GNFs surface-derivatized with reactive linker molecules bearing pendant primary amino functional groups capable of binding covalently to epoxy resins. Of special importance, herringbone GNFs derivatized with 3,4'-oxydianiline (GNF-ODA) were found to react with neat butyl glycidyl ether to form mono-, di-, tri-, and tetraglycidyl oligomers covalently coupled to the ODA pendant amino group. The resulting reactive GNF-ODA (butyl glycidyl)n nanofibers, r-GNF-ODA, are especially well suited for reactive, covalent incorporation into epoxy resins during thermal curing. Based on these studies, nanocomposites reinforced by the r-GNF-ODA nanofibers at nanofiber loadings of 0.15-1.3 wt% were prepared. Flexural property of cured r-GNF-ODA/epoxy nanocomposites were measured through three-point-bending tests. Thermal properties, including glass transition temperature (Tg) and coefficient of thermal expansion (CTE) for the nanocomposites, were investigated using thermal mechanical analysis. The nanocomposites containing 0.3 wt% of the nanofibers gives the highest mechanical properties. At this 0.3-wt% fiber loading, the flexural strength, modulus and breaking strain of the particular nanocomposite are increased by about 26, 20, and 30%, respectively, compared to that of pure epoxy matrix. Moreover, the Tg value is the highest for this nanocomposite, 14°C higher than that of pure epoxy. The almost constant change in CTEs before and after Tg, and very close to the change of pure epoxy, is in agreement with our previous study results on a chemical bond existing between the r-GNF-ODA nanofibers and epoxy resin in the resulting nanocomposites.

Polymers, paint and wood industries, Polymères, industries des peintures et bois, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Industrie des polymeres, peintures, bois, Polymer industry, paints, wood, Technologie des polymères, Technology of polymers, Formes d'application et semiproduits, Forms of application and semi-finished materials, Matériaux composites, Composites, Acide oléique, Oleic acid, Oleico ácido, Amidoacide polymère, Amidoacid polymer, Amidoácido polímero, Estérification, Esterification, Esterificación, Etude expérimentale, Experimental study, Estudio experimental, Imidation, Imidación, Imide polymère, Polyimide, Imida polímero, Matériau composite, Composite material, Material compuesto, Matériau renforcé dispersion, Dispersion reinforced material, Material renforzado dispersión, Nanocomposite, Nanocompuesto, Propriété chimique, Chemical properties, Propiedad química, Propriété dynamomécanique, Dynamic mechanical properties, Propiedad dinamomecánica, Propriété thermique, Thermal properties, Propiedad térmica, Préparation, Preparation, Preparación, Résistance eau, Waterproofness, Impermeabilidad agua, Silice, Silica, Sílice, Stabilité thermique, Thermal stability, Estabilidad térmica, Traitement surface, Surface treatment, and Tratamiento superficie

In this study, a commercially available nano-sized silica (SiO2) was surface-modified via esterification with oleic acid (OA), a relatively inexpensive and hydrophobic modifier. The surface-modified silica (SiO2-OA) nanoparticles were used to disperse in the poly(amic acid) solutions of a commercial polyimide (PI), used for two-layer film, and thermally imidized to form a series of Pl/silica nanocomposites. The effects of the addition of SiO2-OA nanoparticles on the properties of the as-prepared Pl/ silica nanocomposites were studied. The results indicated that the as-prepared Pl/silica nanocomposites exhibited improvements in the dynamic mechanical property, thermal stability, water resistance, and thermal expansion.

Polymers, paint and wood industries, Polymères, industries des peintures et bois, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Industrie des polymeres, peintures, bois, Polymer industry, paints, wood, Technologie des polymères, Technology of polymers, Formes d'application et semiproduits, Forms of application and semi-finished materials, Matériaux composites, Composites, Agent accrochage, Coupling agent, Agente enganche, Biomatériau, Biomaterial, Copolymère réticulé, Crosslinked copolymer, Copolímero reticulado, Degré dispersion, Dispersion degree, Grado dispersión, Dentisterie restauratrice, Dental restoration, Restauración dental, Etude expérimentale, Experimental study, Estudio experimental, Matériau composite, Composite material, Material compuesto, Matériau renforcé dispersion, Dispersion reinforced material, Material renforzado dispersión, Morphologie, Morphology, Morfología, Méthacrylate copolymère, Methacrylate copolymer, Metacrilato copolímero, Nanocomposite, Nanocompuesto, Propriété dynamomécanique, Dynamic mechanical properties, Propiedad dinamomecánica, Relation mise en oeuvre propriété, Property processing relationship, Relación puesta en marcha propiedad, Relation mise en oeuvre structure, Structure processing relationship, Relación puesta en marcha estructura, Silane organique, Organic silane, Silano orgánico, Silice, Silica, Sílice, Traitement surface, Surface treatment, Tratamiento superficie, and Composite dentaire

Advancements in nanocomposites are highly dependent on the compatibility between the organic matrix and inorganic fillers, and the dispersion level of fillers throughout the matrix. Silane coupling agents are widely used to change the chemical structure of particles' surface in order to improve their compatibility and dispersion properties of particles. SiO2nanoparticles were modified by γ-methacryloxy propyl trime-thoxy silane, which provided double bonds to the particle surface. These groups can covalently bond with monomers to form a three-dimensional network within the composites. After the surface modification, the dispersion performance of particles in different media (water, ethanol, acetone) was studied. Infrared spectroscopy and transmission electron microscopy were used to identify the structure of modified SiO2. The dispersion degree and stability properties of modified SiO2 in three media were investigated by the measurements of contact angle, ζ potential, turbidity, and relative viscosity. The results indicate that the stability and dispersion degree in organic solvents have been improved after the modification. In addition, the mechanical properties of composites with modified silica were also studied, which indicated that, after the predispersion of particles in organic media, the mechanical properties of materials could be improved, even at low filler content.

Polymers, paint and wood industries, Polymères, industries des peintures et bois, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Industrie des polymeres, peintures, bois, Polymer industry, paints, wood, Technologie des polymères, Technology of polymers, Constituants de formulation, Compounding ingredients, Matières charges et agents renforçants, Fillers and reinforcing agents, Formes d'application et semiproduits, Forms of application and semi-finished materials, Fibres et fils, Fibers and threads, Amide 66 copolymère, Amide 66 copolymer, Amida 66 copolímero, Amide 66 polymère, Amide 66 polymer, Amida 66 polímero, Amide copolymère, Amide copolymer, Amida copolímero, Copolymère greffé, Graft copolymer, Copolímero injertado, Etude expérimentale, Experimental study, Estudio experimental, Fibre aramide, Aramid fiber, Fibra aramida, Fibre minérale, Mineral fiber, Fibra inorgánica, Fibre synthétique, Synthetic fiber, Fibra sintética, Fibre verre, Glass fiber, Fibra vidrio, Polycondensation, Condensation polymerization, Policondensación, Polymère aliphatique, Aliphatic polymer, Polímero alifático, Polymère aromatique, Aromatic polymer, Polímero aromático, Polymère greffé, Graft polymers, Propriété thermique, Thermal properties, Propiedad térmica, Relation mise en oeuvre propriété, Property processing relationship, Relación puesta en marcha propiedad, Relation mise en oeuvre structure, Structure processing relationship, Relación puesta en marcha estructura, Renforçant, Reinforcing filler, Agente refuerzo, Réaction liquide solide, Liquid solid reaction, Reacción líquido sólido, Réaction surface, Surface reaction, Reacción superficie, Traitement surface, Surface treatment, Tratamiento superficie, Kevlar, and Téréphtalamide p phénylène polymère

Nylon-6,6 was grafted at the surface of glass and plasma-treated Kevlar fibers for use in nylon-Kevlar thermoplastic composites. Hydroxyl and, in the case of Kevlar, amine end-groups occur at the fibre surface, either as defects or due to the plasma treatment. These were used as anchor points for nylon-6,6 step polycondensation. Fibers were subjected to successive dipping in adipoyl chloride/CH2Cl2 and aqueous hexamethylenediamine solutions in order to attach and grow high molecular weight polymer on the fiber surface. Grafted nylon was characterized by Fourier transform infrared spectroscopy, proton nuclear magnetic resonance, differential scanning calorimetry and thermogravimetry. It was shown that no backbiting occurred during the first stage of the grafting process and that the polymer quantity increased linearly with number of passes, up to ∼50 passes for plasma-treated Kevlar and 100 for glass fibers, after which polymer quantity remained constant, within experimental error, which was attributed to the onset of termination reactions.

Polymers, paint and wood industries, Polymères, industries des peintures et bois, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Industrie des polymeres, peintures, bois, Polymer industry, paints, wood, Technologie des polymères, Technology of polymers, Formes d'application et semiproduits, Forms of application and semi-finished materials, Matériaux composites, Composites, Copolymère fluor, Fluorine containing copolymer, Copolímero flúor, Cristallinité, Crystallinity, Cristalinidad, Etude expérimentale, Experimental study, Estudio experimental, Fibre aramide, Aramid fiber, Fibra aramida, Fibre synthétique, Synthetic fiber, Fibra sintética, Fluoration, Fluorination, Fluoración, Matériau composite, Composite material, Material compuesto, Matériau renforcé fibre, Fiber reinforced material, Material reforzado fibra, Oléfine polymère, Olefin polymer, Olefina polímero, Propriété mécanique, Mechanical properties, Propiedad mecánica, Propriété surface, Surface properties, Propiedad superficie, Propriété thermique, Thermal properties, Propiedad térmica, Propène polymère, Propylene polymer, Propeno polímero, Relation mise en oeuvre propriété, Property processing relationship, Relación puesta en marcha propiedad, Relation mise en oeuvre structure, Structure processing relationship, Relación puesta en marcha estructura, Renforcement mécanique, Strengthening, Refuerzo mecánico, Traitement chimique, Chemical treatment, Tratamiento químico, Traitement surface, Surface treatment, Tratamiento superficie, Coulée solution, and Téréphtalamide(p-phénylène) polymère

Polymer fibers are one of the main substances used for the reinforcement of plastic composites. Surface modification of aramid fiber was performed by direct fluorination. The crystallinity and the decomposition temperature of the modified fiber were increased. Scanning electron microscope shows that the roughness increases in the modified fiber. Composites were prepared by using modified and unmodified fibers. It was shown that the mechanical and thermal properties increase for modified fiber reinforcing composites. To reduce the fiber degradation or breakdown, composites were prepared by solution casting method.

Polymers, paint and wood industries, Polymères, industries des peintures et bois, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Industrie des polymeres, peintures, bois, Polymer industry, paints, wood, Technologie des polymères, Technology of polymers, Formes d'application et semiproduits, Forms of application and semi-finished materials, Stratifiés, Laminates, Propriété interface, Interface properties, Propiedad interfase, Adhésivité, Adhesivity, Adhesividad, Agent accrochage, Coupling agent, Agente enganche, Amide polymère, Nylon, Amida polímero, Analyse surface, Surface analysis, Análisis superficie, Condensation chimique, Condensation reaction, Condensación química, Epoxyde résine, Epoxy resin, Epóxido resina, Etude expérimentale, Experimental study, Estudio experimental, Fibre aramide, Aramid fiber, Fibra aramida, Fibre synthétique, Synthetic fiber, Fibra sintética, Interface fibre matrice, Matrix fiber interface, Interfase fibra matriz, Matériau composite, Composite material, Material compuesto, Matériau fibre unidirectionnelle, Unidirectional fiber material, Material fibra unidireccional, Matériau renforcé fibre, Fiber reinforced material, Material reforzado fibra, Polymère aromatique, Aromatic polymer, Polímero aromático, Propriété mécanique, Mechanical properties, Propiedad mecánica, Résistance cisaillement, Shear strength, Resistencia cizallamiento, Silane organique, Organic silane, Silano orgánico, Stratifié, Laminate, Estratificado, Traitement surface, Surface treatment, Tratamiento superficie, Kevlar, Résistance cisaillement interlaminaire, and Téréphtalamide p phénylène polymère

This research applied the methodology of metalation and grafting alkoxysilane to modify the surface of Kevlar-29 fiber. The surface properties of the modified Kevlar fiber were characterized by scanning electron microscopy, X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, atomic force microscopy, and Brunauer-Emmett-Teller isothermal adsorption analysis. The relationship between surface characteristics of Kevlar fiber and its interfacial adhesion of Kevlar fiber-reinforced epoxy resin composites was also discussed. Compared with the untreated fiber, the surface of the modified Kevlar fiber was much rougher, its oxygen content increased by about 12%, the surface area enlarged about 10 times, and the wetting behavior improved. Due to the modification of the fiber, the adhesion between the fiber and the resin matrix was markedly improved and the Interlaminar Shear Strength of its epoxy composites increased by about 57%.

Polymers, paint and wood industries, Polymères, industries des peintures et bois, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Industrie des polymeres, peintures, bois, Polymer industry, paints, wood, Technologie des polymères, Technology of polymers, Formes d'application et semiproduits, Forms of application and semi-finished materials, Matériaux composites, Composites, Agent intercalant, Intercalating agent, Agente intercalante, Amide 6 polymère, Amide 6 polymer, Amida 6 polímero, Argile organique, Organic clay, Arcilla orgánica, Argile, Clay, Arcilla, Composé de l'ammonium quaternaire, Quaternary ammonium compound, Amonio cuaternario compuesto, Degré dispersion, Dispersion degree, Grado dispersión, Etude expérimentale, Experimental study, Estudio experimental, Matériau composite, Composite material, Material compuesto, Matériau renforcé dispersion, Dispersion reinforced material, Material renforzado dispersión, Montmorillonite, Montmorilonita, Morphologie, Morphology, Morfología, Moulage injection, Injection molding, Moldeo por inyección, Nanocomposite, Nanocompuesto, Polymère aliphatique, Aliphatic polymer, Polímero alifático, Propriété dynamomécanique, Dynamic mechanical properties, Propiedad dinamomecánica, Propriété mécanique, Mechanical properties, Propiedad mecánica, Propriété thermique, Thermal properties, Propiedad térmica, Propriété traction, Tensile property, Propiedad tracción, Relation mise en oeuvre propriété, Property processing relationship, Relación puesta en marcha propiedad, Résistance flexion, Bending strength, Resistencia flexión, Stabilité thermique, Thermal stability, Estabilidad térmica, Traitement surface, Surface treatment, and Tratamiento superficie

Polyamide-6/clay nanocomposites were prepared employing melt bending or compounding technique followed by injection molding using different organically modified clays. X-ray diffraction and transmission electron microscopy were used to determine the molecular dispersion of the modified clays within the matrix polymer. Mechanical tests revealed an increase in tensile and flexural properties of the matrix polymer with the increase in clay loading from 0 to 5%. C30B/polyamide-6 nanocomposites exhibited optimum mechanical performance at 5% clay loading. Storage modulus of polyamide-6 also increased in the nanocomposites, indicating an increase in the stiffness of the matrix polymer with the addition of nanoclays. Furthermore, water absorption studies confirmed comparatively lesser tendency of water uptake in these nanocomposites. HDT of the virgin matrix increased substantially with the addition of organically modified clays. DSC measurements revealed both γ and a transitions in the matrix polymer as well as in the nanocomposites. The crystallization temperature (Tc) exhibited an increase in case of C30B/ polyamide-6 nanocomposites. Thermal stability of virgin polyamide-6 and the nanocomposites has been investigated employing thermogravimetric analysis.