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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 cationique, Cationic surfactant, Agente superficie catiónico, Argile organique, Organic clay, Arcilla orgánica, Argile, Clay, Arcilla, Dérivé du benzimidazole, Benzimidazole derivatives, Benzimidazol derivado, Etude expérimentale, Experimental study, Estudio experimental, Inflammabilité, Flammability, Inflamabilidad, Matériau composite, Composite material, Material compuesto, Montmorillonite, Montmorilonita, Morphologie, Morphology, Morfología, Méthacrylate de méthyle polymère, Methyl methacrylate polymer, Metacrilato de metilo polímero, Nanocomposite, Nanocompuesto, Propriété thermique, Thermal properties, Propiedad térmica, Préparation, Preparation, Preparación, Stabilité thermique, Thermal stability, Estabilidad térmica, Styrène polymère, Styrene polymer, Estireno polímero, Traitement surface, Surface treatment, Tratamiento superficie, Benzimidazolium composé, Benzimidazolium, Dispersion, Fire retardancy, and Polymer nanocomposites

In this paper, the synthesis of a one-chain benzimidazolium surfactant is accomplished and polystyrene (PS) and poly(methyl methacrylate) (PMMA) nanocomposites with organoclay modified by the above surfactant are prepared by melt blending. XRD, TEM, TGA and cone calorimetry are employed to evaluate the dispersion of the clay in the polymer matrices, thermal stability and fire behavior. TEM results show that the clay disperses more uniformly in the PMMA matrix than in PS. Both polymer nanocomposites exhibit enhanced thermal stability. From cone calorimetry, substantial reduction of heat release rates is obtained at 3wt% and 5wt% of clay from polystyrene and a more remarkable reduction in PMMA.

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, Ignifugeants, retardateurs de flamme et réducteurs de fumée, Fireproof agents, Formes d'application et semiproduits, Forms of application and semi-finished materials, Matériaux composites, Composites, Acide phosphorique, Phosphoric acid, Fosfórico ácido, Additif, Additive, Aditivo, Ammonium Polyphosphate, Ammonium Polyphosphates, Amonio Polifosfato, Ester polymère, Ester polymer, Ester polímero, Etude expérimentale, Experimental study, Estudio experimental, Fibre lin, Flax fiber, Fibra lino, Fibre naturelle, Natural fiber, Fibra natural, Fibre végétale, Plant fiber, Fibra vegetal, Inflammabilité, Flammability, Inflamabilidad, Matériau composite, Composite material, Material compuesto, Matériau renforcé fibre, Fiber reinforced material, Material reforzado fibra, Phosphate d'ammonium, Ammonium phosphate, Amonio fosfato, Phosphorylation, Fosforilación, Polymère aliphatique, Aliphatic polymer, Polímero alifático, Propriété thermique, Thermal properties, Propiedad térmica, Relation formulation propriété, Property formulation relationship, Relación formulación propiedad, Relation mise en oeuvre propriété, Property processing relationship, Relación puesta en marcha propiedad, Retardateur flamme, Flame retardant, Retardador llama, Succinate polymère, Polysuccinate, Succinato polímero, Traitement surface, Surface treatment, Tratamiento superficie, Biocomposite, Butène succinate polymère, Ammonium polyphosphate, Biocomposites, Dihydrogen ammonium phosphate, Flax, and Surface modification

This paper investigates the effect of three phosphorous compounds on the thermal and fire behavior of PBS/flax biocomposites: ammonium polyphosphate (APP), dihydrogen ammonium phosphate (DAP) and phosphoric acid (PA). A comparison of the additive and reactive routes for the fireproofing of biocomposites is investigated by TGA, PCFC and cone calorimetry. The incorporation by additive route of APP, DAP and PA in biocomposites leads to the charring effect of flax fibers due to the phosphorylation and the dehydration of the cellulose, (the main component of flax fibers). PA leads to a lower condensed phase action compared to APP and DAP. PBS hot hydrolysis is also highlighted due to the presence of phosphorous compounds in the matrix. In the reactive route, DAP and PA are grafted onto flax fibers. The first temperature of degradation, assigned to flax degradation, is progressively shifted to lower temperature with increasing grafting rate while the amount of residue is also enhanced. Using this route, no PBS hydrolysis occurs. The proximity of the phosphorous compound with the flax fibers allows the formation of a strong char at lower phosphorus content. This char residue acts as a protective layer that limits gas and heat transfer, allowing the decrease of pHRR and MARHE.

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, Absorbant UV, Ultraviolet absorbent, Absorbente UV, Additif, Additive, Aditivo, Aluminium Hydroxyde, Aluminium Hydroxides, Aluminio Hidróxido, Dégradation photochimique, Photochemical degradation, Degradación fotoquímica, Dégradation thermique, Thermal degradation, Degradación térmica, Dérivé de la benzophénone, Benzophenone derivatives, Benzofenona derivado, Effet concentration, Concentration effect, Efecto concentración, Etude expérimentale, Experimental study, Estudio experimental, Hydroxyde double lamellaire, Layered double hydroxide, Hidróxido doble laminar, Magnésium Hydroxyde, Magnesium Hydroxides, Magnesio Hidróxido, Matériau composite, Composite material, Material compuesto, Morphologie, Morphology, Morfología, Propriété thermique, Thermal properties, Propiedad térmica, Stabilisant, Stabilizer agent, Estabilizante, Stabilisation thermique, Thermal stabilization, Estabilización térmica, Stabilité photochimique, Photochemical stability, Estabilidad fotoquímica, Stabilité thermique, Thermal stability, Estabilidad térmica, Traitement surface, Surface treatment, Tratamiento superficie, Vieillissement accéléré, Artificial ageing, Envejecimiento acelerado, Vieillissement thermique, Thermal ageing, Envejecimiento térmico, Vinylique chlorure polymère, Polyvinyl chloride, Vinílico cloruro polímero, Vieillissement photochimique, Intercalation, Layered double hydroxide (LDH), Poly(vinyl chloride), and Stabilization

2-hydroxy-4-methoxybenzophenone-5-sulfonic acid (BP) anion-intercalated Mg-AI-carbonated layered double hydroxide (LDH) (LDH-BP) was prepared by an ion-exchange method. The structure of LDH-BP was characterized by XRD, FTIR and TG-DTA. The accelerated weathering and thermal stability of PVC/ LDH-BP composites were investigated by color change, oxidation products, surface morphology, and thermal stability time. In addition to the sacrificing role of BP anion structure by absorbing the incident light and transmitting the rest of the light in a non-harmful form, the ability of LDH-BP to scatter the incident light and to absorb the released HCI improves the resistance to both accelerated weathering and thermal degradation.

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, Ignifugeants, retardateurs de flamme et réducteurs de fumée, Fireproof agents, Formes d'application et semiproduits, Forms of application and semi-finished materials, Matériaux composites, Composites, Additif, Additive, Aditivo, Aluminium Composé, Aluminium Compounds, Aluminio Compuesto, Argile organique, Organic clay, Arcilla orgánica, Butène téréphtalate polymère, Butene terephthalate polymer, Buteno tereftalato polímero, Composé de l'ammonium quaternaire, Quaternary ammonium compound, Amonio cuaternario compuesto, Dégradation thermique, Thermal degradation, Degradación térmica, Ester polymère, Ester polymer, Ester polímero, Etude expérimentale, Experimental study, Estudio experimental, Fibre minérale, Mineral fiber, Fibra inorgánica, Fibre verre, Glass fiber, Fibra vidrio, Inflammabilité, Flammability, Inflamabilidad, Matériau composite, Composite material, Material compuesto, Matériau renforcé fibre, Fiber reinforced material, Material reforzado fibra, Montmorillonite, Montmorilonita, Mécanisme réaction, Reaction mechanism, Mecanismo reacción, Phosphinate organique, Organic phosphinate, Fosfinato orgánico, Polymère brome, Bromine containing polymer, Polímero bromo, Propriété thermique, Thermal properties, Propiedad térmica, Relation formulation propriété, Property formulation relationship, Relación formulación propiedad, Retardateur flamme, Flame retardant, Retardador llama, Stabilité thermique, Thermal stability, Estabilidad térmica, Styrène(halogéno) polymère, Halostyrene polymer, Estireno(halógeno) polímero, Traitement surface, Surface treatment, Tratamiento superficie, Retardateur flamme sans halogène, Styrène(2,4,6-tribromo) polymère, Styrène(bromo) polymère, Aluminium diethyl phosphinate, Brominated polystyrene, Halogen free flame retardant, Methyl, octadecyl, bis-2-hydroxyethyl quaternary ammonium salt, and Poly(butylene terephthalate)

The performance and mechanism of brominated and halogen free flame retardants in formulations of glass fibre reinforced poly(butylene terephthalate) composites were investigated. This study entailed four glass fibre reinforced PBT formulations, namely, (i) glass fibre reinforced PBT without flame retardant, (ii) glass fibre reinforced PBT combined with one brominated flame retardant (10 wt% of brominated polystyrene), (iii) glass fibre reinforced PBT combined with one halogen free flame retardant (15 wt % of aluminium diethyl phosphinate), and (iv) glass fibre reinforced PBT combined with two halogen free flame retardants (15.5 wt% of aluminium diethyl phosphinate and 2.5 wt% of natural montmorillonite clay modified with methyl, octadecyl, bis-2-hydroxyethyl quaternary ammonium salt). Their fire performance is compared using LOl, UL-94, thermogravimetric analysis (TGA), differential thermogravimetry (DTG), evolved Fourier transform infrared gas analysis (TGA-FTIR), Fourier transform infrared solid residue analysis (FTIR-ATR), and cone calorimetric studies. The results of this study show that aluminium diethyl phosphinate combined with natural montmorillonite clay, chemically modified with a quaternary ammonium salt, provides an alternative to brominated flame retardants in glass fibre reinforced PBT composites.

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, Argile, Clay, Arcilla, Biodégradabilité, Biodegradability, Biodegradabilidad, Butyrate(hydroxy) polymère, Butyrate(hydroxy)polymer, Butirato(hidroxi) polímero, Compostage, Composting, Compostaje, Composé de l'ammonium quaternaire, Quaternary ammonium compound, Amonio cuaternario compuesto, Cristallinité, Crystallinity, Cristalinidad, Dégradation biologique, Biodegradation, Degradación biológica, Ester polymère, Ester polymer, Ester polímero, Etude expérimentale, Experimental study, Estudio experimental, Matériau composite, Composite material, Material compuesto, Montmorillonite, Montmorilonita, Morphologie, Morphology, Morfología, Mouillabilité, Wettability, Remojabilidad, Nanocomposite, Nanocompuesto, Polymère aliphatique, Aliphatic polymer, Polímero alifático, Propriété biologique, Biological properties, Propiedad biológica, Propriété surface, Surface properties, Propiedad superficie, Traitement surface, Surface treatment, Tratamiento superficie, Butyrate(3-hydroxy) polymère, Cloisite 15A, Polymère biodégradable, Compost, Disintegrability, Nanoclay, Nanocomposites, Organic modification, and Poly(hydroxybutyrate)

Polymer nanocomposites, based on a bacterial biodegradable thermoplastic polyester, poly(hydroxybutyrate) (PHB), and unmodified montmorillonite Cloisite Na' (CNa) and chemically modified Cloisite 15A and 93A (C15A and C93A), were prepared through a solution route. The nanostructure has been established through X-ray diffraction (XRD), while the nanocomposites were characterized by differential scanning calorimetry (DSC), contact angle measurements, and thermogravimetric (TGA) analysis. Disintegrability in composting conditions has been tested at certain times (0, 7,14, 21, 28 and 35 days at 58 C) and the effect of different nanoclays on the properties of biodegraded films was deeply investigated. XRD results suggest a better dispersion for C15A and C93A based nanocomposites that present also a more surface hydrophobic nature respect to PHB matrix and PHB nanocomposite loaded with unmodified Cloisite. This result is in accord with disintegrability behavior of PHB nanocomposites. Visual observation, chemical, thermal and morphological investigations proved that the disintegration in composting conditions was faster for PHB_4CNa respect to the systems loaded with modified clays suggesting the possibility to modulate the disintegrability capacity of PHB selecting a specific filler.

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, Alcoolyse, Alcoholysis, Alcoholisis, Carbonate polymère, Polycarbonate, Carbonato polímero, Cinétique, Kinetics, Cinética, Dégradation thermique, Thermal degradation, Degradación térmica, Energie activation, Activation energy, Energía activación, Etude expérimentale, Experimental study, Estudio experimental, Matériau composite, Composite material, Material compuesto, Modèle cinétique, Kinetic model, Modelo cinético, Modélisation, Modeling, Modelización, Mécanisme réaction, Reaction mechanism, Mecanismo reacción, Nanocomposite, Nanocompuesto, Propriété thermique, Thermal properties, Propiedad térmica, Silane organique, Organic silane, Silano orgánico, Silice, Silica, Sílice, Stabilité thermique, Thermal stability, Estabilidad térmica, Traitement surface, Surface treatment, Tratamiento superficie, Mélangeage état fondu, Kinetic analysis, and Nanocomposites

Polycarbonate nanocomposites filled with pristine and modified silica were prepared by simple melt compounding. The thermal degradation behavior of composites was investigated by thermogravimetric analysis coupled with differential scanning calorimetry (TGA/DSC). To understand the thermal degradation mechanism, the chemical structures of gaseous and solid degradation products were detected by thermogravimetric analysis coupled with Fourier transform infrared spectrometry (TGA/FTIR) and X-ray photoelectron spectroscopy (XPS), respectively. Kissinger-Akahira-Sunose (KAS) and Flynn-Wall -Ozawa (FWO) methods were employed to analyze the thermal degradation kinetics. High thermal degradation temperature was obtained by incorporating both types of nanoparticles into matrix, but the maximum mass loss rate increased. According to the DSC curves for degradation process, the change of the number and position of absorption peaks meant that the degradation mechanism of composites was different from that of neat PC. The analysis for TGA chars confirmed the presence of alcoholysis reaction between PC and silica nanoparticles during the thermal decomposition. TGA/FTIR results proved that no new degradation volatiles were produced during the thermal degradation of composites, but the total amounts of all gaseous products decreased by adding silica nanoparticles. The degradation activation energies of both composites increased significantly relative to neat PC, especially for the composite with modified silica.

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, Ignifugeants, retardateurs de flamme et réducteurs de fumée, Fireproof agents, Formes d'application et semiproduits, Forms of application and semi-finished materials, Matériaux composites, Composites, Additif, Additive, Aditivo, Agent accrochage, Coupling agent, Agente enganche, Argile, Clay, Arcilla, Chlore Composé organique, Chlorine Organic compounds, Cloro Compuesto orgánico, Effet concentration, Concentration effect, Efecto concentración, Ester polymère, Ester polymer, Ester polímero, Ethylène téréphtalate polymère, Ethylene terephthalate polymer, Etileno tereftalato polímero, Hétérocycle azote phosphore, Nitrogen phosphorus heterocycle, Heterociclo nitrógeno fósforo, Inflammabilité, Flammability, Inflamabilidad, Matériau composite, Composite material, Material compuesto, Montmorillonite, Montmorilonita, Morphologie, Morphology, Morfología, Propriété thermique, Thermal properties, Propiedad térmica, Retardateur flamme, Flame retardant, Retardador llama, Silane organique, Organic silane, Silano orgánico, Stabilité thermique, Thermal stability, Estabilidad térmica, Traitement surface, Surface treatment, Tratamiento superficie, Cyclotriphosphazène dérivé, Flame retardancy, Hexachlorocyclotriphosphazene, and PET composites

The flame retardancy and thermal properties of neat poly (ethylene terephthalate) (PET) and flame-retarded PET were investigated, hexachlorocyclotriphosphazene modified by montmorillonite (HCCP-OMMT) was used as the flame retardant. The composites were prepared by melt blending neat PET with flame retardant and named as PET/HCCP-OMMT. Three levels of HCCP-OMMT (1%, 3% and 5%) were considered for the blends. Thermal property of PET/HCCP-OMMT composites was studied by thermogravimetric analysis (TGA), and only 3% additive was found to significantly enhance the thermal stability of PET both in air and nitrogen at high temperature. It was found that the composites could pass UL-94 V-0 and LOI value 31.5 just containing 3% of HCCP-OMMT. The Py-GC/MS study showed that the cyclotriphosphazene and montmorillonite still remained in the residue during the pyrolysis of HCCP-OMMT. Besides that, the introduction of HCCP-OMMT would inhibit the pyrolysis of PET during heating or burning. The morphology and the chemical structure of the charred residue were detected by SEM and FTIR respectively. Results demonstrated that a good barrier was provided by the char of composites and improved the thermal behaviors during burning. TEM results suggested that intercalating type composite by melt blending can be formed.

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, Additif, Additive, Aditivo, Conductivité électrique, Electrical conductivity, Conductividad eléctrica, Dégradation thermooxydante, Thermooxidative degradation, Degradación termooxidante, Effet concentration, Concentration effect, Efecto concentración, Etude expérimentale, Experimental study, Estudio experimental, Matériau composite, Composite material, Material compuesto, Nanocomposite, Nanocompuesto, Nanotube carbone, Carbon nanotubes, Nanotube multifeuillets, Multiwalled nanotube, Oléfine polymère, Olefin polymer, Olefina polímero, Phénols, Phenols, Fenoles, Propriété mécanique, Mechanical properties, Propiedad mecánica, Propriété rhéologique, Rheological properties, Propiedad reológica, Propriété thermique, Thermal properties, Propiedad térmica, Propriété traction, Tensile property, Propiedad tracción, Propriété électrique, Electrical properties, Propiedad eléctrica, Propène polymère, Propylene polymer, Propeno polímero, Recuit, Annealing, Recocido, Stabilisant chaleur, Heat stabilizer, Estabilizador calor, Stabilité thermique, Thermal stability, Estabilidad térmica, Traitement surface, Surface treatment, Tratamiento superficie, Traitement thermique, Heat treatment, Tratamiento térmico, Viscoélasticité, Viscoelasticity, Viscoelasticidad, Nanotube carbone fonctionnalisé, Multiwalled carbon nanotubes, Polypropylene, and Thermal oxidation

The combined effect of melt annealing and surface modification of multiwalled carbon nanotubes (MWCNT) on polypropylene (PP) based nanocomposites is reported. Melt annealing markedly improved the filler dispersion in PP. The rheological and electrical percolative threshold was achieved at a content of 3 wt% MWCNT, due to the dynamic reconstruction of nanotube network in the polymer matrix. This behaviour was particularly evident in the case of surface-modified MWCNT. However, the heat treatment also induced an overall worsening of mechanical properties due to polymer heterogeneous oxidation at a microscopic scale, as detected by oxygen mapping through SEM/EDS. Crack initiation sites eventually leading to the failure of the polymer were formed due to peroxide-mediated spreading of oxidation, radiating from residual polymerisation catalyst particles. FTIR-ATR spectroscopy demonstrated that blooming of the phenol stabilizer due to thermal annealing was responsible for early oxidation of polypropylene. The reported results highlight the advantages and drawbacks of physical strategies designed to improve the dispersion stability of nanotubes in polymer 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, Constituants de formulation, Compounding ingredients, Stabilisants (antioxygènes, antiozones, etc.), Stabilizers (antioxydants, antiozonants, etc.), Formes d'application et semiproduits, Forms of application and semi-finished materials, Matériaux composites, Composites, Additif, Additive, Aditivo, Antioxydant, Antioxidant, Antioxidante, Densité réticulation, Crosslink density, Densidad reticulado, Diffusion molécule, Molecule scattering, Difusión molécula, Dérivé du benzimidazole, Benzimidazole derivatives, Benzimidazol derivado, Etude expérimentale, Experimental study, Estudio experimental, Matériau composite, Composite material, Material compuesto, Propriété chimique, Chemical properties, Propiedad química, Propriété mécanique, Mechanical properties, Propiedad mecánica, Propriété optique, Optical properties, Propiedad óptica, Propriété thermique, Thermal properties, Propiedad térmica, Préparation, Preparation, Preparación, Résistance traction, Tensile strength, Resistencia tracción, SBR, Silice, Silica, Sílice, Stabilisant, Stabilizer agent, Estabilizante, Stabilité thermique, Thermal stability, Estabilidad térmica, Structure moléculaire, Molecular structure, Estructura molecular, Temps exposition, Exposure time, Tiempo exposición, Traitement surface, Surface treatment, Tratamiento superficie, Vieillissement thermique, Thermal ageing, Envejecimiento térmico, Vulcanisat, Vulcanizate, Vulcanizado, 2-Mercaptobenzimidazole, Antioxidative behavior, and Styrene-butadiene rubber

A novel type of rubber antioxidant, silica-supported 2-mercaptobenzimidazole (SiO2-s-MB), was prepared by reacting 2-mercaptobenzimidazole (MB) with chlorosilane-modified silica (m-SiO2). Raman spectroscopy, FT-IR, XPS and TGA confirmed that MB was chemically bonded onto the surfaces of silica particles. SEM observation showed that SiO2-s-MB was homogeneously dispersed in the styrene-butadiene rubber (SBR) matrix. Based on the measurement of oxidation induction time (OIT) of SBR/ SiO2-s-MB and SBR/m-SiO2/MB composites containing equivalent antioxidant components, it was found that the antioxidative efficiency of SiO2-s-MB was superior to that of the corresponding low molecular MB. By determining the changes of tensile strength, elongation at break and crosslinking density of SBR composites during long-term accelerated aging, it was shown that the thermal oxidative stability of SBR/ SiO2-s-MB composites was much higher than that of SBR/m-SiO2/MB composites. Furthermore, the color contamination, migration and volatility of SiO2-s-MB were lower than those of MB, indicating that SiO2-s-MB is environmentally friendly.

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, Domaines d'application, Application fields, Sciences biologiques et medicales, Biological and medical sciences, Sciences biologiques fondamentales et appliquees. Psychologie, Fundamental and applied biological sciences. Psychology, Industries agroalimentaires, Food industries, Généralités, General aspects, Manutention, stockage, conditionnement, transport, Handling, storage, packaging, transport, Absorption optique, Optical absorption, Absorción óptica, Agent surface, Surfactant, Agente superficie, Biodégradabilité, Biodegradability, Biodegradabilidad, Butyrate(hydroxy) polymère, Butyrate(hydroxy)polymer, Butirato(hidroxi) polímero, Cellulose, Celulosa, Compostage, Composting, Compostaje, Dégradation biologique, Biodegradation, Degradación biológica, Emballage matière plastique, Plastic bag packaging, Empaque material plástico, Ester polymère, Ester polymer, Ester polímero, Etirabilité, Stretchability, Estirabilidad, Etude expérimentale, Experimental study, Estudio experimental, Extrusion, Extrusión, Lactique acide polymère, Lactic acid polymer, Láctico ácido polímero, Matériau composite, Composite material, Material compuesto, Matériau renforcé dispersion, Dispersion reinforced material, Material renforzado dispersión, Mouillabilité, Wettability, Remojabilidad, Mélange polymère, Polymer blends, Nanocomposite, Nanocompuesto, Nanocristal, Nanocrystal, Perméabilité gaz, Gas permeability, Permeabilidad gas, Polymère aliphatique, Aliphatic polymer, Polímero alifático, Produit alimentaire, Foodstuff, Producto alimenticio, Propriété biologique, Biological properties, Propiedad biológica, Propriété chimique, Chemical properties, Propiedad química, Propriété mécanique, Mechanical properties, Propiedad mecánica, Propriété optique, Optical properties, Propiedad óptica, Propriété rhéologique, Rheological properties, Propiedad reológica, Propriété surface, Surface properties, Propiedad superficie, Propriété technologique, Technological properties, Propiedad tecnológica, Propriété transport, Transport properties, Propiedad transporte, Résistance eau, Waterproofness, Impermeabilidad agua, Traitement surface, Surface treatment, Tratamiento superficie, Viscosité, Viscosity, Viscosidad, Barrier properties, Modified cellulose nanocrystals, Nanocomposites, Poly(hydroxybutyrate), and Poly(lactic acid)

Nanocomposite films based on poly(lactic acid)-poly(hydroxybutyrate) (PLA-PHB) blends and synthesized cellulose nanocrystals (CNC) or surfactant modified cellulose nanocrystals (CNCs), as bio-based reinforcement, were prepared by melt extrusion followed by film forming. The obtained nanocomposites are intended for short-term food packaging. Thus, the mechanical, optical, barrier and wettability properties were studied. Functionalized CNCs contribute to enhance the interfacial adhesion between PLA and PHB, leading to improved mechanical stiffness and increased film stretchability. The synergic effects of the PHB and CNCs on the PLA barrier properties were confirmed by increases in oxygen barrier properties and reductions in surface wettability of the nanocomposites. In addition, the measurements of the viscosity molecular weight for ternary systems showed practically no degradation of PLA and smaller degradation of PHB during processing due to nanocrystal presence. The disintegration process in composting conditions of PLA was delayed by the addition of PHB, while CNC speeded it up. PLA-PHB-CNCs formulations showed enhanced mechanical performance, improved water resistance, reduced oxygen and UV-light transmission, as well as appropriate disintegration in compost suggesting possible applications as packaging materials.

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 biologique, Biosurfactant, Agente superficie biológico, Biodégradabilité, Biodegradability, Biodegradabilidad, Copolymère greffé, Graft copolymer, Copolímero injertado, Culture microorganisme, Microorganism culture, Cultivo microorganismo, Dégradation biologique, Biodegradation, Degradación biológica, Effet concentration, Concentration effect, Efecto concentración, Etude expérimentale, Experimental study, Estudio experimental, Glycolipide, Glycolipid, Glicolípido, Gomme ghatti, Ghatti gum, Goma ghatti, Lipoprotéine, Lipoprotein, Lipoproteina, Matériau composite, Composite material, Material compuesto, Moulage extrusion, Extrusion molding, Moldeo por extrusión, Mélange maître, Masterbatch, Mezcla maestra, Nanobâtonnet, Nanorod, Nanopalito, Nanocomposite, Nanocompuesto, Propriété biologique, Biological properties, Propiedad biológica, Propriété dynamomécanique, Dynamic mechanical properties, Propiedad dinamomecánica, Stabilité thermique, Thermal stability, Estabilidad térmica, Styrène polymère, Styrene polymer, Estireno polímero, Sulfate de calcium, Calcium sulfate, Calcio sulfato, Traitement surface, Surface treatment, Tratamiento superficie, Rhamnolipide, Surfactine, Biopolymer, and Polystyrene

Nanocomposites of polystyrene and CaSO4 nanorods with different loadings have been prepared by mixing pre-synthesized biopolymer (gum ghatti) and biosurfactant (rhamnolipid and surfactin) grafted CaSO4 nanorods into commercial polystyrene with the combination of solvent blending and extrusion molding from masterbatch. In this work, it is shown that surfactin-graft-CaSO4, (i) enhanced the dispersion of the nanorods within the matrix, (ii) increased the thermal stability and thermomechanical properties indicating good reinforcement, and (iii) resulted in higher biodegradation efficiency as compared to the nanocomposites filled with rhamnolipid-graft-CaSO4 or gum ghatti-graft-CaSO4. Biodegradation of polystyrene nanocomposites was assessed using a microbial inoculum (Rhodococcus pyridinivorans NT2) in a 28-day biodegradation assay. The viability of the isolate growing on the film surface was confirmed using a triphenyltetrazolium chloride reduction test. The viability was also correlated with a concomitant increase in the protein density of the biomass. The mechanical properties of nanocomposites were significantly reduced after the microbial degradation. Biodegradation of the materials was further confirmed by the decreased molecular weight through gel permeation chromatography, and changes in the chemical structure as verified by Fourier transform infrared spectroscopy. This was supported by the degraded surface of the films observed under filed emission scanning electron microscopy (FESEM). The effects of biodegradation on the thermal properties were studied through the differential scanning calorimetry and thermogravimetry. To improve our knowledge of polystyrene biodegradation, we used Raman spectroscopy to identify patterns of polystyrene biodegradation. In addition, the intermediates formed in the degradation process were monitored by Gas Chromatography -Mass Spectrometry and the biodegradation rate of the materials was determined by measuring the carbon dioxide (CO2) evolution. These results indicate that surface grafting of nano-CaSO4 with surfactin leads to optimal degradation of the 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, Composé de l'iminium, Iminium compounds, Iminio compuesto, Dérivé de l'imidazole, Imidazole derivatives, Imidazol derivado, Energie activation, Activation energy, Energía activación, Etude expérimentale, Experimental study, Estudio experimental, Liquide ionique, Ionic liquid, Líquido iónico, Matériau composite, Composite material, Material compuesto, Module conservation, Storage modulus, Módulo conservación, Nanocomposite, Nanocompuesto, Nanotube carbone, Carbon nanotubes, Nanotube monofeuillet, Singlewalled nanotube, Nanotubo pared única, Nanotube multifeuillets, Multiwalled nanotube, Propriété rhéologique, Rheological properties, Propiedad reológica, Styrène polymère, Styrene polymer, Estireno polímero, Superposition température temps, Temperature time superposition, Superposición temperatura tiempo, Traitement surface, Surface treatment, Tratamiento superficie, Viscoélasticité, Viscoelasticity, Viscoelasticidad, Imidazolium(1-méthyl-3-octyl) tétrafluoroborate, Dynamic mechanical analysis, Polystyrene, and Time―temperature superposition

Dynamic mechanical analysis (DMA) measurements have been used for determining the viscoelastic behaviour of polystyrene (PS) nanocomposites containing a 1 wt.% of single- or multi-walled carbon nanotubes, both pristine (SWCNT and MWCNT) and modified by previous treatment with a roomtemperature ionic liquid (SWCNTm and MWCNTm). Two sets of multiple frequency tests have been carried out. The Arrhenius relationship has been used to estimate the apparent activation energies for the glass transition. Master curves have been generated using the time-temperature superposition principle. The nanocomposites show an increase of the activation energy up to an 8% with respect to PS, in the order PS + MWCNT > PS + MWCNTm > PS + SWCNTm > PS + SWCNT > PS. The nanophases also induce a displacement of the onset of the storage modulus to longer times following the order PS + SWCNTm > PS + SWCNT > PS + MWCNT > PS + MWCNTm > PS, at 40 °C. At higher temperatures, the storage modulus onset is very similar for all materials. In the case of PS + SWCNTm, the period of time for the onset of the storage modulus is multiplied by a factor of 28 with respect to PS. The surface modification of the SWCNT by the ionic liquid could improve the interfacial compatibility. The results described here show that a very low proportion of carbon nanotubes can effectively improve the long-term stability of PS under service temperature conditions.

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, Biodégradabilité, Biodegradability, Biodegradabilidad, Cellulose ester organique, Cellulose organic ester, Celulosa ester orgánico, Cellulose, Celulosa, Dégradation biologique, Biodegradation, Degradación biológica, Dérivé de la cellulose, Cellulose derivatives, Celulosa derivado, Estérification, Esterification, Esterificación, Etude expérimentale, Experimental study, Estudio experimental, Fibre naturelle, Natural fiber, Fibra natural, Fibre végétale, Plant fiber, Fibra vegetal, Fungi, Maléique anhydride, Maleic anhydride, Maleico anhídrido, Matériau composite, Composite material, Material compuesto, Méthacrylate de méthyle polymère, Methyl methacrylate polymer, Metacrilato de metilo polímero, Méthacrylique acide ester méthyle, Methyl methacrylate, Metacrílico ácido ester metilo, Nanofibre, Nanofiber, Nanofibra, Oléfine polymère, Olefin polymer, Olefina polímero, Polymérisation radicalaire, Free radical polymerization, Polimerización radicalar, Polymérisation suspension, Suspension polymerization, Polimerización suspensión, Propriété biologique, Biological properties, Propiedad biológica, Propriété rhéologique, Rheological properties, Propiedad reológica, Sol, Soils, Suelo, Traitement surface, Surface treatment, Tratamiento superficie, Viscosité, Viscosity, Viscosidad, Microfibre, Cellulose fibers, Scanning electron microscopy, and Thermal analysis

Synthetic plastics like polyolefins, acrylics which are widely used in consumer products are not biodegraded by microorganisms in the environment. The accumulation of plastics in the environment becomes a matter of great concern leading to long-term environment, economic and waste management problems. In order to overcome these problems, significant attention has been given on biodegradable polymers, and also, on the identification of microorganisms with degrading potential upon polymeric materials. Therefore, recycling and biodegradation of these polymers is an important issue for environmental protection. The present work evaluates the effect of Maleic anhydride (MA) and Methylmethacrylate (MMA) modified cellulose micro and nano fibres (MACF and MMCF respectively) on the biodegradation behaviour of Polymethylmethacrylate (PMMA)/cellulose composites. MA and MMA modified cellulose reinforced PMMA composite granules were prepared by in-situ suspension polymerization technique. PMMA/cellulose composite films were prepared by solution casting method and the biodegradation behaviour of the films was studied by soil burial method in two types of soils (Soil A and Soil B). The biodegraded films were characterized by weight loss study, viscosity average molecular weights, scanning electron microscopy (SEM), differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FrIR) and Nuclear magnetic resonance spectroscopy (NMR). The isolation and identification of the fungus, which degraded these composites, were done for the first time along with the biodegradation study with the isolated pure culture.

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, Ignifugeants, retardateurs de flamme et réducteurs de fumée, Fireproof agents, Formes d'application et semiproduits, Forms of application and semi-finished materials, Matériaux composites, Composites, Additif, Additive, Aditivo, Aluminium Composé, Aluminium Compounds, Aluminio Compuesto, Amide 66 polymère, Amide 66 polymer, Amida 66 polímero, Effet composition, Composition effect, Efecto composición, Etude expérimentale, Experimental study, Estudio experimental, Fibre verre, Glass fiber, Fibra vidrio, Inflammabilité, Flammability, Inflamabilidad, Matériau composite, Composite material, Material compuesto, Matériau renforcé fibre, Fiber reinforced material, Material reforzado fibra, Mécanisme réaction, Reaction mechanism, Mecanismo reacción, Phosphinate organique, Organic phosphinate, Fosfinato orgánico, Polymère aliphatique, Aliphatic polymer, Polímero alifático, Propriété thermique, Thermal properties, Propiedad térmica, Retardateur flamme, Flame retardant, Retardador llama, Revêtement protecteur, Protective coatings, Revestimiento protector, Traitement surface, Surface treatment, Tratamiento superficie, Vernis, Varnish, Barniz, Intumescence, Aluminum diethylphosphinate, Flame retardancy, Intumescent coating, Mechanism, and Polyamide 6,6

Polyamide 6,6 (PA6,6) is usually fire retarded in bulk, using aluminum diethylphosphinate (AlPi). In one of our recent papers, it was shown that good fire-retardant properties (e.g. V0 at the UL94 test) could also be achieved by applying an intumescent varnish on the PA6,6 surface. Excellent fire-retardant properties were even obtained combining 5% of AlPi in the bulk with an intumescent coating applied on the polymer surface. The Glow Wire Flammability Index (GWFI) test was validated at 960 °C whereas it was only validated at 750 °C without the AlPi. This paper first aims to describe the mechanism of action of an intumescent coating to protect a polymer, as it was never previously studied in the literature. It was evidenced, analyzing with 13C, 31P and 27Al solid state NMR spectra of the materials at different combustion times that during burning one part of the virgin polymer begins to degrade and is mixed with the semi-viscous charring intumescent layer. In some way, due to this mixture of both phases, it is as if the polymer was fire retarded in bulk during burning. The second objective was to investigate the potential synergy between the gas phase fire-retardant mechanism of AlPi and the condensed phase fire protective mechanism of the intumescent coating to explain the enhanced fire-retardant properties. Similarly, using NMR technique, the interest to combine the bulk treatment in low amount and the intumescent coating was evidenced: the AlPi cannot completely sublimate because of the protective coating, and is probably condensed inside the intumescent structure pores. As it is trapped in the condensed phase, it then degrades into aluminophosphates, increasing the heat barrier efficiency of the expanded char layer.

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, Ignifugeants, retardateurs de flamme et réducteurs de fumée, Fireproof agents, Additif, Additive, Aditivo, Composé de l'ammonium, Ammonium compound, Amonio compuesto, Céramique oxyde, Oxide ceramics, Cerámica óxido, Effet concentration, Concentration effect, Efecto concentración, Etude expérimentale, Experimental study, Estudio experimental, Extrusion, Extrusión, Inflammabilité, Flammability, Inflamabilidad, Lactique acide polymère, Lactic acid polymer, Láctico ácido polímero, Matériau composite, Composite material, Material compuesto, Nanocomposite, Nanocompuesto, Phosphate de zirconium, Zirconium phosphate, Zirconio fosfato, Phosphoramidate organique, Organic amidophosphate, Fosforamidato orgánico, Polymère aliphatique, Aliphatic polymer, Polímero alifático, Propriété thermique, Thermal properties, Propiedad térmica, Préparation, Preparation, Preparación, Retardateur flamme, Flame retardant, Retardador llama, Stabilité thermique, Thermal stability, Estabilidad térmica, Traitement surface, Surface treatment, Tratamiento superficie, 1,3,2-Dioxaphosphinane dérivé, Intumescence, Cone calorimetry, and Poly(lactic acid)

A novel functionalized α-zirconium phosphate (F-ZrP) modified with intumescent flame retardant was synthesized by co-precipitation method and characterized. Poly (lactic acid) (PLA)/F-ZrP nanocomposites were prepared by melt blending method. The thermal stability and combustion behavior of PLA/F-ZrP nanocomposites were investigated by thermogravimetric analysis (TGA), limiting oxygen index (LOI), vertical burning test (UL-94), scanning electronic microscopy (SEM), and cone calorimeter test (CCT). The results showed that the addition of flame retardant F-ZrP slightly affect PLA's thermal stability, but significantly improve the flame retardancy of PLA composites. In comparison with neat PLA, the LOI value of PLA/F-ZrP was increased from 19.0 to 26.5, and the UL-94 rating was enhanced to V-0 as the loading of F-ZrP at 10%. SEM results suggested the introduction of F-ZrP in the PLA system can form compact intumescent char layer during burning. All these results showed that the F-ZrP performed good flame retardancy for PLA. .

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, Caoutchouc bromobutyle, Bromobutyl rubber, Caucho bromobutilo, Cinétique, Kinetics, Cinética, Composé de l'iminium, Iminium compounds, Iminio compuesto, Conductivité thermique, Thermal conductivity, Conductividad térmica, Dégradation thermique, Thermal degradation, Degradación térmica, Dérivé de l'imidazole, Imidazole derivatives, Imidazol derivado, Effet concentration, Concentration effect, Efecto concentración, Energie activation, Activation energy, Energía activación, Etude expérimentale, Experimental study, Estudio experimental, Liquide ionique, Ionic liquid, Líquido iónico, Matériau composite, Composite material, Material compuesto, Morphologie, Morphology, Morfología, Nanocomposite, Nanocompuesto, Propriété thermique, Thermal properties, Propiedad térmica, Stabilité thermique, Thermal stability, Estabilidad térmica, Température transition vitreuse, Glass transition temperature, Temperatura transición vítrosa, Traitement surface, Surface treatment, Tratamiento superficie, Graphène oxyde, Imidazolium(1-butyl-3-méthyl) hexafluorophosphate, Graphene oxide, and Ionic liquids

In this report, we demonstrate that both the thermal stability and the thermal conductivity of bromobutyl rubber (BIIR) nanocomposites could be improved by incorporating the ionic liquids (ILs) modified graphene oxide (GO-ILs) using a solution compounding method. The structure, thermal stability and thermal conductivity of this newly modified BIIR nanocomposites were systematically analyzed and studied. The X-ray diffraction (XRD) analysis of GO-ILs showed that ILs had been effectively intercalated into the interlayer of GO, which was found to be able to raise the exfoliation degree of GO. The increased exfoliation degree facilitated a good dispersion of GO-ILs in the BIIR matrix, as revealed by the scanning electron microscope (SEM) images. The glass transition temperatures (Tg) of the GO-ILs/BIIR nanocomposites were also raised by the addition of GO-ILs, which indicates the strong interfacial adhesion between GO-ILs and the rubber. Most importantly, the incorporation of GO-ILs in the BIIR matrix could effectively improve the thermal stability of the rubber nanocomposites according to our thermogravimetric analysis (TGA). The activation energy (Ea) of thermal decomposition of GO-ILs/BIIR nanocomposites increases with the addition of GO-ILs. Besides, the thermal conductivity of GO-ILs/BIIR nanocomposite with 4 wt% of GO-ILs had 1.3-fold improvement compared to that of unfilled BIIR.

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, Alcanoate(hydroxy) polymère, Alkanoate(hydroxy) polymer, Alcanoato(hidroxi) polímero, Biodégradabilité, Biodegradability, Biodegradabilidad, Ester polymère, Ester polymer, Ester polímero, Etude expérimentale, Experimental study, Estudio experimental, Fibre naturelle, Natural fiber, Fibra natural, Fibre végétale, Plant fiber, Fibra vegetal, Maléique anhydride, Maleic anhydride, Maleico anhídrido, 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 aliphatique, Aliphatic polymer, Polímero alifático, Polymère fonctionnel, Functional polymer, Polímero funcional, Polymère réticulé, Crosslinked polymer, Polímero reticulado, Propriété biologique, Biological properties, Propiedad biológica, Propriété chimique, Chemical properties, Propiedad química, Propriété mécanique, Mechanical properties, Propiedad mecánica, Propriété rhéologique, Rheological properties, Propiedad reológica, Préparation, Preparation, Preparación, Résistance eau, Waterproofness, Impermeabilidad agua, Réticulation, Crosslinking, Reticulación, Silicate organique, Organic silicate, Silicato orgánico, Thé, Tea, Té, Traitement surface, Surface treatment, Tratamiento superficie, Viscosité, Viscosity, Viscosidad, Biodegradation, Crosslinking technique, Poly(hydroxyalkanoate), and Tea plant fiber

The biodegradability, morphology, and mechanical properties of composite materials made from maleic anhydride-grafted poly(hydroxyalkanoate) (PHA-g-MA) and treated (crosslinked) tea plant fibre (t-TPF) were evaluated. Composites containing PHA-g-MA (PHA-g-MA/t-TPF) had noticeably superior mechanical properties compared with those of PHA/TPF because of greater compatibility with TPF. The dispersion of t-TPF in the PHA-g-MA matrix was more homogeneous because of ester formation and the consequent creation of branched and crosslinked macromolecules between the anhydride carboxyl groups of PHA-g-MA and hydroxyl groups in t-TPF. Additionally, the PHA-g-MA/t-TPF composites were more easily processed because of their lower melt viscosities. The water resistance of PHA-g-MA/t-TPF was higher than that of PHA/TPF, although the weight loss of composites buried in soil compost indicated that both were biodegradable, especially at high levels of TPF substitution. The PHA/TPF and PHA-g-MA/t-TPF composites were more biodegradable than pure PHA, which implied a strong connection between TPF content and biodegradability.

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, Sciences biologiques et medicales, Biological and medical sciences, Sciences medicales, Medical sciences, Chirurgie (generalites). Transplantations, greffes d'organes et de tissus. Pathologie des greffons, Surgery (general aspects). Transplantations, organ and tissue grafts. Graft diseases, Technologie. Biomatériaux. Equipements, Technology. Biomaterials. Equipments, Acrylique acide polymère, Acrylic acid polymer, Acrílico ácido polímero, Caprolactone copolymère, Caprolactone copolymer, Caprolactona copolímero, Caprolactone polymère, Polycaprolactone, Caprolactona polímero, Dépôt plasma, Plasma deposition, Depósito plasma, Etude expérimentale, Experimental study, Estudio experimental, Extrusion, Extrusión, Lactone copolymère, Lactone copolymer, Lactona copolímero, Lactone polymère, Lactone polymer, Lactona polímero, Matériau composite, Composite material, Material compuesto, Module Young, Young modulus, Módulo Young, Polymère aliphatique, Aliphatic polymer, Polímero alifático, Polymère optiquement actif, Optically active polymer, Polímero ópticamente activo, Polymérisation décharge électrique, Glow discharge polymerization, Polimerización descarga eléctrica, Polyélectrolyte, Polyelectrolyte, Polielectrolito, Pressage chaud, Hot pressing, Prensado caliente, Propriété mécanique, Mechanical properties, Propiedad mecánica, Propriété thermique, Thermal properties, Propiedad térmica, Propriété traction, Tensile property, Propiedad tracción, Résistance traction, Tensile strength, Resistencia tracción, Stabilité thermique, Thermal stability, Estabilidad térmica, Traitement par plasma, Plasma assisted processing, Traitement surface, Surface treatment, Tratamiento superficie, Verre, Glass, Vidrio, Bioverre, Lactide copolymère, Lactide polymère, Bioactive glass, Plasma polymerization, Polylactides, Polylactones, and Surface modification

Poly(L-lactide) (PLLA), poly(e-caprolactone) (PCL) and poly(L-lactide/ε-caprolactone) (PLCL) are medical (co)polyesters that are conventionally manufactured by thermoplastic processing techniques, such as injection molding or extrusion. However, the addition of bioglass particles causes a degradation reaction of the matrix at high temperatures and could limit the fabrication of composite systems by the above mentioned processes. In this work, a surface modification of bioactive glass particles by plasma polymerization of acrlylic acid is proposed as a strategy for the improvement of thermal stability of bioglass filled composite systems. The developed poly(acrylic acid) layer on the surface of bioglass particles, hinders the degradation reaction between the Si-O- groups present in the surface of the particles and the C=O groups of the polymer's backbone. As an illustration, the onset degradation temperature (Tonset) of PLLA, PCL and PLCL increased respectively from 185.0, 240.1 and 192.2 for bioglass (BG) filled composites to 240.4, 299.5 and 245.7 °C for their modified bioglass (mBG) filled counterparts. Finally, neat PLLA and composites having 15 vol.% of BG and mBG were melt-compounded and subsequently hot pressed to obtain tensile test samples. Non-modified bioglass filled PLLA film was too brittle and difficult to handle due to the sharp reduction of molecular weight during thermoplastic processing. On the contrary, modified bioglass filled PLLA presented a slight increase in Young's modulus with respect to unfilled PLLA but a decrease in both tensile strength and elongation at break.

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 sulfonique, Sulfonic acid, Acido sulfónico, Agent accrochage, Coupling agent, Agente enganche, Aire surface spécifique, Specific surface area, Aluminium Oxyhydroxyde, Aluminium Hydroxides oxides, Aluminio Oxihidróxido, Boehmite, Boehmita, Céramique oxyde, Oxide ceramics, Cerámica óxido, Dégradation thermooxydante, Thermooxidative degradation, Degradación termooxidante, Energie activation, Activation energy, Energía activación, Ethylène basse densité polymère, Low density ethylene polymer, Etileno baja densidad polímero, Etude expérimentale, Experimental study, Estudio experimental, Fumée silice, Silica fume, Humo sílice, Matériau composite, Composite material, Material compuesto, Mécanisme réaction, Reaction mechanism, Mecanismo reacción, Nanocomposite, Nanocompuesto, Oléfine polymère, Olefin polymer, Olefina polímero, Propriété thermique, Thermal properties, Propiedad térmica, Relation mise en oeuvre propriété, Property processing relationship, Relación puesta en marcha propiedad, Silane organique, Organic silane, Silano orgánico, Stabilité thermique, Thermal stability, Estabilidad térmica, Traitement surface, Surface treatment, Tratamiento superficie, Mélangeage état fondu, Low-density polyethylene (LDPE), Nanocomposites, Silica, and Thermal degradation

Fumed silica (FS) and synthetic boehmite alumina (BA) nanofillers with and without surface treatments were incorporated in 5 wt. % in low density polyethylene (LDPE) through melt blending. FS was treated using hexadecyl silane, whereas BA using octyl silane and alkylbenzene sulfonic acid. The related nanocomposites were subjected to pyrolysis gas chromatography-mass spectrometry (Py-GC-MS) and thermogravimetric analysis (TGA) under isothermal and dynamic conditions, respectively. Py-GC-MS results proved that the thermal degradation mechanism did not change in the presence of the nanofillers. The latter suppressed the formation of high molecular weight hydrocarbons and affected the relative amounts of diene/alkene/alkane fragments for each hydrocarbon fraction. Dynamic TGA scans were registered at different heating rates in air. The activation energy (Eα) of thermoxidative degradation was calculated by the Ozawa-Flynn-Wall (OFW) method at various degradation degrees. Eα of the LDPE nanocomposites depended on both specific surface area and surface treatment of the nanofillers used. The former enhanced whereas the latter decreased the activation energy for the LDPE-FS nanocomposites. By contrast, Eα was slightly increased for the surface treated LDPE-BA 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, Constituants de formulation, Compounding ingredients, Ignifugeants, retardateurs de flamme et réducteurs de fumée, Fireproof agents, Formes d'application et semiproduits, Forms of application and semi-finished materials, Matériaux composites, Composites, Aluminium Hydroxyde, Aluminium Hydroxides, Aluminio Hidróxido, Benzoate, Benzoato, Calcium Hydroxyde, Calcium Hydroxides, Calcio Hidróxido, Degré dispersion, Dispersion degree, Grado dispersión, Etude expérimentale, Experimental study, Estudio experimental, Hydroxyde double lamellaire, Layered double hydroxide, Hidróxido doble laminar, Inflammabilité, Flammability, Inflamabilidad, Magnésium Hydroxyde, Magnesium Hydroxides, Magnesio Hidróxido, Matériau composite, Composite material, Material compuesto, Morphologie, Morphology, Morfología, Méthacrylate de méthyle polymère, Methyl methacrylate polymer, Metacrilato de metilo polímero, Nanocomposite, Nanocompuesto, Polymérisation masse, Bulk polymerization, Polimerización masa, Propriété thermique, Thermal properties, Propiedad térmica, Stabilité thermique, Thermal stability, Estabilidad térmica, Styrène polymère, Styrene polymer, Estireno polímero, Traitement surface, Surface treatment, Tratamiento superficie, Zinc Hydroxyde, Zinc Hydroxides, Zinc Hidróxido, Fire retardancy, Layered double hydroxides, Poly(methyl-methacrylate), and Polystyrene

The influence of three different divalent metals, calcium, magnesium and zinc, using benzoate-modified layered double hydroxides (LDHs), on the dispersion and fire properties of polystyrene (PS) and poly(methyl-methacrylate) (PMMA) is investigated. PS- and PMMA-layered double hydroxide (PS/LDHs PMMA/LDHs) nanocomposites are prepared by in situ bulk polymerization in the presence of the benzoate-modified LDHs. The morphology of the nanocomposites is characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM). XRD results indicate that the characteristic layered structure of Ca―Al―LDH―B completely disappear in both polymers, whereas for Zn―Al―LDH―B and Mg ―Al―LDH―B that is not the case. TEM confirms excellent dispersion and exceptional distribution of exfoliated Ca―Al―LDH―B within both polymer matrices, while for Zn―Al―LDH―B and Mg―Al―LDH―B dispersion is poorer with more tactoids present. Thermal stability and fire properties are investigated by thermogravimetric analysis (TGA) and cone calorimetry (CC). All PMMA nanocomposites show enhanced thermal stability compared to neat PMMA, while thermal stability of PS is enhanced only by the addition of Ca―Al―LDH―B. PS/Ca―Al―LDH―B and PS/Zn―Al―LDH―B systems show better fire properties compared to the PS/Mg―Al―LDH―B; peak heat release rate reduction is 42 and 41%, respectively, vs. only 15% for the PS/Mg―Al―LDH―B at 10% LDH loading. The largest peak heat release rate reduction (PHRR), 52%, is measured for the PMMA/Mg―Al―LDH―B nanocomposites at 10% LDH loading, although dispersion is very poor. PHRR reduction of the PMMA/Ca―Al―LDH―B nanocomposites at 10% LDH loading is 45%, while 30% reduction of the PHRR is measured for nanocomposites containing 10% Zn―Al―LDH―B.