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Metallurgy, welding, Métallurgie, soudage, Polymers, paint and wood industries, Polymères, industries des peintures et bois, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Physicochimie des polymeres, Physicochemistry of polymers, Industrie des polymeres, peintures, bois, Polymer industry, paints, wood, Technologie des polymères, Technology of polymers, Absorption eau, Water absorption, Absorción agua, Adhésif, Adhesive, Adhesivo, Assemblage collé, Adhesive joint, Ensambladura pegada, Durabilité, Durability, Durabilidad, Epoxyde résine, Epoxy resin, Epóxido resina, Fibre carbone, Carbon fiber, Fibra carbón, Fibre minérale, Mineral fiber, Fibra inorgánica, Joint recouvrement, Lap joint, Junta recubierta, Matériau composite, Composite material, Material compuesto, Matériau renforcé dispersion, Dispersion reinforced material, Material renforzado dispersión, Mode rupture, Fracture mode, Modo ruptura, Nanocomposite, Nanocompuesto, Nanotube carbone, Carbon nanotubes, Plasma, Polymère, Polymer, Polímero, Stratifié, Laminate, Estratificado, Traitement par plasma, Plasma assisted processing, Traitement surface, Surface treatment, Tratamiento superficie, Vieillissement accéléré, Artificial ageing, Envejecimiento acelerado, Vieillissement thermique, Thermal ageing, Envejecimiento térmico, Nanofibre carbone, Vieillissement hygrothermique, Carbon nanotubes and nanofibres, Composites, and Epoxy

The effect of water absorption on the strength of single lap adhesive joints subjected to accelerated hygrothermal ageing (55 C, 95% relative humidity, 800 h) was analysed. Two different variables were studied: the surface treatment of the carbon fibre/epoxy laminates (peel ply, grit blasting and atmospheric pressure plasma) and the addition of carbon nanofillers (0.5 wt% nanofibres and 0.25 wt% nanotubes) to the epoxy adhesive. The joint strength and the failure mode of the joints were investigated. Furthermore, the amount of water absorbed by the adhesive was determined. Adhesive joints with peel ply-treated laminates exhibit an increase in their strength, which is attributed to a relaxation of stresses in the adhesive/laminate interface; with grit blasting, this property remains almost constant. Plasma treatment provides the worst ageing behaviour because this treatment results in a surface with a higher surface free energy, which is more susceptible to environmental attack. The nanoreinforcement of the adhesive has a beneficial effect: it decreases the amount of absorbed water.

Metallurgy, welding, Métallurgie, soudage, Polymers, paint and wood industries, Polymères, industries des peintures et bois, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Physicochimie des polymeres, Physicochemistry of polymers, Industrie des polymeres, peintures, bois, Polymer industry, paints, wood, Technologie des polymères, Technology of polymers, Adhérence, Adhesion, Adherencia, Adhésif, Adhesive, Adhesivo, Epoxyde résine, Epoxy resin, Epóxido resina, Mouillabilité, Wettability, Remojabilidad, Optimisation, Optimization, Optimización, Plasma, Polymère, Polymer, Polímero, Propriété mécanique, Mechanical properties, Propiedad mecánica, Propriété surface, Surface properties, Propiedad superficie, Propriété traction, Tensile property, Propiedad tracción, Rugosité, Roughness, Rugosidad, Traitement par plasma, Plasma assisted processing, Traitement surface, Surface treatment, Tratamiento superficie, Contact angles, Epoxy, Metals, and Surface treatment by plasma

Steel surfaces have been modified using low pressure microwave plasma to enhance its adhesion with an epoxy adhesive. Optimization of the wettability of the surface was done using contact angle measurements for varying plasma parameters. Maximum wettability (19.9') was obtained at 1000 W microwave power with 20 min of treatment time, ―50 V sample bias and 1.67% O2/Ar gas flow rate ratio. Enhanced wettability of the steel surface was attributed to increased surface roughness and oxide deposition. Using atomic force microscopy, surface roughness was observed to increase from 64.4 nm for the untreated surface to 76.7 nm for the O2/Ar plasma treated surface. Deposition of oxides on the steel surface was also confirmed by the energy dispersive x-ray spectroscopy. Moreover, the increase in the total surface energy to 53.2 mN/m for the O2 plasma treated steel surface supported the enhancement of its wettability, and hence, the adhesion with epoxy. Based on tensile test results, the adhesion strength of epoxy-bonded O2/Ar plasma treated surfaces at optimum settings was increased to 3816.0 N, which is significantly higher compared to 3038.3 N for the epoxy-bonded untreated surfaces.

Metallurgy, welding, Métallurgie, soudage, Polymers, paint and wood industries, Polymères, industries des peintures et bois, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Physicochimie des polymeres, Physicochemistry of polymers, Industrie des polymeres, peintures, bois, Polymer industry, paints, wood, Technologie des polymères, Technology of polymers, Additif, Additive, Aditivo, Adhésif, Adhesive, Adhesivo, Alumine, Alumina, Alúmina, Assemblage collé, Adhesive joint, Ensambladura pegada, Céramique oxyde, Oxide ceramics, Cerámica óxido, Durabilité, Durability, Durabilidad, Hydroxyde d'aluminium, Aluminium hydroxide, Aluminio hidróxido, Hydroxyde de magnésium, Magnesium hydroxide, Magnesio hidróxido, Matériau revêtement, Coating material, Material revestimiento, Oxyde de magnésium, Magnesium oxide, Magnesio óxido, Polymère, Polymer, Polímero, Résistance corrosion, Corrosion resistance, Resistencia corrosión, Solution chimique, Chemical solution, Solución química, Traitement surface, Surface treatment, Tratamiento superficie, AZ31 magnesium sheets, Lap-shear, Surface treatment by chemical solutions, and X-ray photoelectron spectroscopy

A pretreat phosphate solution having the formulation of KMnO4, K2HPO4, Na2SiO3, NaF and Na2MoO4 was developed to improve the strength of adhesive-bonded magnesium AZ31 joints. The phosphate coating which has the magnesium phosphate, MgO, Mg (OH)2, MgF2 and minor Al2O3, Al(OH)3 Al0.35―0.55Si0.01―0.4sP0.13―0.35O2.1―2.2 and, Al0.35Si0.48P0.18O2.2, and Al0.52P0.48O2.2 was formed on the surface of the magnesium AZ31 after treatment. The additives Na2MoO4 in a phosphate-permanganate solution mainly act as an accelerator to speed up the coating formation. The combination of Na2MoO4 and NaF improves significantly the corrosion resistance of the magnesium AZ31 and performance of adhesive bonded joints. The joint strength and durability of the bonded Mg AZ31 joints in hot-humid environmental condition are superior to that of the phosphate treated (RPT) and CrO3 etching (CET) pretreated samples.

Metallurgy, welding, Métallurgie, soudage, Polymers, paint and wood industries, Polymères, industries des peintures et bois, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Physicochimie des polymeres, Physicochemistry of polymers, Industrie des polymeres, peintures, bois, Polymer industry, paints, wood, Technologie des polymères, Technology of polymers, Adhérence, Adhesion, Adherencia, Adhésif, Adhesive, Adhesivo, Adhésivité, Adhesivity, Adhesividad, Aluminium alliage, Aluminium alloy, Aluminio aleación, Dispersant, Dispersante, Dispersion aqueuse, Aqueous dispersion, Dispersión acuosa, Groupe carboxyle, Carboxyl group, Grupo carboxilo, Liant, Binders, Ligante, Matériau revêtement, Coating material, Material revestimiento, Mode rupture, Fracture mode, Modo ruptura, Polymère, Polymer, Polímero, Propriété mécanique, Mechanical properties, Propiedad mecánica, Propriété surface, Surface properties, Propiedad superficie, Résistance pelage, Peel strength, Resistencia pelado, Traitement surface, Surface treatment, Tratamiento superficie, Uréthanne polymère, Polyurethane, Uretano polímero, Aluminum and alloys, Peel, and Water based

A waterborne polyurethane coating with reflectivity higher than 95% in the visible wavelength range of 380-750 nm has been formulated. The impact of pigment concentration and carboxyl functional dispersing agent percentage on the adhesion of this waterborne polyurethane-based coating to an aluminum substrate is characterized at various pigment weight fractions by peel strength using modified ASTM D 1876-93. The formulated coating was also examined by SEM, UV/vis spectrophotometer with integrating sphere, and ATR―FTIR. Results indicate that the reflectivity of the coating increases with pigment volume concentration while the peel strength decreases. At high pigment-to-binder ratios a change in failure mode from adhesive to cohesive was observed. Further experiments indicate that adhesion increased at high pigment-to-binder ratios due to the presence of carboxyl functional groups of the dispersing agent. The increase in adhesion was identified for the first time and attributed to the interaction of the carboxyl functional groups in the dispersing agent with the aluminum surface.

Metallurgy, welding, Métallurgie, soudage, Polymers, paint and wood industries, Polymères, industries des peintures et bois, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Physicochimie des polymeres, Physicochemistry of polymers, Industrie des polymeres, peintures, bois, Polymer industry, paints, wood, Technologie des polymères, Technology of polymers, Adhésivité, Adhesivity, Adhesividad, Durabilité, Durability, Durabilidad, Matériau revêtement, Coating material, Material revestimiento, Morphologie, Morphology, Morfología, Nanostructure, Nanoestructura, Plasma, Polymère, Polymer, Polímero, Propriété surface, Surface properties, Propiedad superficie, Rugosité, Roughness, Rugosidad, Silice, Silica, Sílice, Surface rupture, Fracture surface, Superficie ruptura, Traitement par plasma, Plasma assisted processing, Traitement surface, Surface treatment, Tratamiento superficie, Atmospheric pressure plasma, Titanium and alloys, and Wedge test

This paper evaluates wet-chemical pre-treatments (alkaline etching, anodising) and a plasma treatment for structural bonding of titanium (Ti6Al4V). The main objective of this study is the comparison of the applicability of the plasma pre-treatment to wet-chemical treatments on titanium for structural bonding. In this context, an atmospheric pressure plasma device was used to deposit thin functional films from hexamethyldisiloxane (HMDSO) precursor on titanium. X-ray photoelectron spectroscopy (XPS) was employed to assess the chemical composition of the surface after different pre-treatments on the titanium substrate, while the morphology and the film thickness were investigated with scanning electron microscopy (SEM). The adhesion properties on titanium were evaluated by means of a wedge test in hot/wet conditions. After bonding tests the fracture surface and the failure loci were analysed. Using a long arc plasma generator and HMDSO precursor almost stoichiometric SiO2 coatings were obtained on the titanium substrate. These coatings exhibit good long-term durability and bond strength compared to an alkaline etching in the wedge test. The investigated anodising process leads to oxide layers revealing a highly porous nanostructure. In contrast to the alkaline etching, the plasma derived coatings and the oxide layer produced by the anodising process exhibit a higher micro, respectively nano roughness, and hence a better long-term durability.

Metallurgy, welding, Métallurgie, soudage, Polymers, paint and wood industries, Polymères, industries des peintures et bois, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Physicochimie des polymeres, Physicochemistry of polymers, Industrie des polymeres, peintures, bois, Polymer industry, paints, wood, Technologie des polymères, Technology of polymers, Adhérence, Adhesion, Adherencia, Copolymère séquencé, Block copolymer, Copolímero secuencia, Matériau composite, Composite material, Material compuesto, Mécanique rupture, Fracture mechanics, Mecánica ruptura, Polymère, Polymer, Polímero, Solution chimique, Chemical solution, Solución química, Traitement surface, Surface treatment, Tratamiento superficie, Adhésif automordançant, Adhesion by mechanical interlocking, Microtensile bond strength, and Surface treatment by chemical solutions

Objectives: The aim of this study was to evaluate the influence of storage time on the bond strength of self-etching adhesive systems to artificially demineralized dentin submitted to application of a papain-based chemical mechanical agent for carious tissue removal. Materials and Methods: Twenty-four blocks of human coronal dentin were randomly divided into 2 groups: (1) restored with a two-step self-etching adhesive system (Clearfil SE Bond); (2) restored with a one-step self-etching adhesive system (One-Up Bond F Plus). After artificial caries induction, the specimens were treated with papain-based gel, received an application of the adhesive system according to the respective group, and blocks of microhybrid resin composite measuring 5.0 mm high and 5.0 mm wide were fabricated incrementally on the tooth, which would later be cut to obtain sticks with a bond area of around 1 mm2, for use in the microtensile tests. After this, half of the sticks obtained from each tooth were submitted to the microtensile test 24 h later, while the other half were stored in water, in an oven at 37 C for a period of 180 d. The specimens were submitted to the microtensile test in a Universal Test Machine at a speed of 0.5 mm/min. The surfaces of the fractured test specimens were examined visually under a stereoscopic loupe in order to classify the fracture type. After exploratory analysis of the data, the two-way Analysis of Variance (ANOVA) and the Tukey test were applied. The data on the fracture types were analyzed by the Exact Fisher test. Results: No statistically relevant differences were verified among the means of the microtensile bond strength values of the adhesive systems evaluated in the different storage times. Mixed and adhesive fractures types were observed for both groups. Conclusion: Storage time did not influence the bond strength of the two-step or one-step self-etching adhesive systems to artificially demineralized dentin submitted to application of a papain-based chemical mechanical agent for carious tissue removal. Both adhesive systems provided similar bond strength at different storage times.

Metallurgy, welding, Métallurgie, soudage, Polymers, paint and wood industries, Polymères, industries des peintures et bois, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Physicochimie des polymeres, Physicochemistry of polymers, Industrie des polymeres, peintures, bois, Polymer industry, paints, wood, Technologie des polymères, Technology of polymers, Adhérence, Adhesion, Adherencia, Aire surface spécifique, Specific surface area, Faisceau électronique, Electron beam, Haz electrónico, Fibre carbone, Carbon fiber, Fibra carbón, Fibre minérale, Mineral fiber, Fibra inorgánica, Interphase, Interfase, Matériau composite, Composite material, Material compuesto, Oxydation, Oxidation, Oxidación, Polymère, Polymer, Polímero, Propriété interface, Interface properties, Propiedad interfase, Propriété mécanique, Mechanical properties, Propiedad mecánica, Propriété surface, Surface properties, Propiedad superficie, Résistance cisaillement, Shear strength, Resistencia cizallamiento, Traitement surface, Surface treatment, Tratamiento superficie, Résistance cisaillement interfacial, Cure/hardening, Fibers, and Interphases

Oxidized and non-oxidized carbon fibers were used to investigate the influence of an oxidation surface treatment on the adhesion strength with an acrylate resin cured by electron beam. For each type of fiber, a complete characterization of the surface properties was done (topography at a nanometric scale, specific surface area, X-ray photoelectron spectroscopy analysis and dispersive and polar components of the surface energy). The adhesion strength was measured by a pull-out test. For comparison, an isothermal UV curing of the matrix was also investigated. The value of the interfacial shear strength, determined by Greszczuk's model, was increased by the oxidation of the carbon fiber surface in the case of UV curing. In the case of electron beam curing, low values were obtained for both types of fibers, which could be explained by an incomplete cure of the matrix at the interface. .

Metallurgy, welding, Métallurgie, soudage, Polymers, paint and wood industries, Polymères, industries des peintures et bois, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Physicochimie des polymeres, Physicochemistry of polymers, Industrie des polymeres, peintures, bois, Polymer industry, paints, wood, Technologie des polymères, Technology of polymers, Adhérence, Adhesion, Adherencia, Matériau composite, Composite material, Material compuesto, Matériau fibre unidirectionnelle, Unidirectional fiber material, Material fibra unidireccional, Matériau renforcé fibre, Fiber reinforced material, Material reforzado fibra, Mode rupture, Fracture mode, Modo ruptura, Polymère, Polymer, Polímero, Propriété mécanique, Mechanical properties, Propiedad mecánica, Préimprégné, Prepreg, Preimpregnado, Résistance cisaillement, Shear strength, Resistencia cizallamiento, Traitement surface, Surface treatment, Tratamiento superficie, Vieillissement thermique, Thermal ageing, Envejecimiento térmico, Adhésif composite, Adhésif structural, Vieillissement hygrothermique, AF-555M adhesive, Adhesion failure mode analysis, Composite lap shear specimens, Peel-ply surface treatment, T800H/3900-2 adherends, and Temperature/humidity aging

Fiber reinforced resin matrix composites and structural adhesives have found increased usage on commercial and military aircraft. These structural materials offer weight savings without sacrificing strength and mechanical performance. Since service history and long-term aging performance of these relatively new material systems are not well established, a long-term environmental aging study was undertaken. Adhesive bonds were prepared by secondary bonding of 3M™ Scotch-Weld™ AF-555M between pre-cured, unidirectional composite adherends comprised of Toray™ T800H/3900-2 prepreg. Single lap shear specimens (SLS) were fabricated and subsequently aged in an unstressed configuration at 82 °C (180 F) and 85% relative humidity for up to 772 days. The aging conditions are more severe than those expected to occur in service and were selected in order to observe some changes within a reasonable exposure time. The apparent shear strengths were measured periodically at both room temperature and 82 °C (180 F), and failure modes were determined and compared to control specimens that had been stored for equal periods of time at room temperature under low humidity. With hygrothermal aging, apparent shear strengths decreased and some changes in the failure mode were observed relative to those of the control specimens. However, in spite of the severe aging conditions, no adhesive failures indicative of interfacial failures were observed. SLS specimens that were hygrothermally aged, subsequently dried, and then tested did not exhibit complete recovery of unaged apparent shear strengths indicating some irreversible changes.

Metallurgy, welding, Métallurgie, soudage, 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, Domaines d'application, Application fields, Bois. Papiers. Non tissés, Wood. Paper. Non wovens, Panneaux et bois améliorés, Wood-based materials, Adhésif, Adhesive, Adhesivo, Adhésivité, Adhesivity, Adhesividad, Aminoplaste, Aminoplast, Aminoplasto, Assemblage collé, Adhesive joint, Ensambladura pegada, Bois, Wood, Madera, Contreplaqué, Plywood, Contrachapeado, Etude expérimentale, Experimental study, Estudio experimental, Matériau revêtement, Coating material, Material revestimiento, Propriété mécanique, Mechanical properties, Propiedad mecánica, Propriété surface, Surface properties, Propiedad superficie, Relation mise en oeuvre propriété, Property processing relationship, Relación puesta en marcha propiedad, Résistance cisaillement, Shear strength, Resistencia cizallamiento, Stratifié, Laminate, Estratificado, Traitement par plasma, Plasma assisted processing, Traitement surface, Surface treatment, Tratamiento superficie, Uréthanne polymère, Polyurethane, Uretano polímero, Travail adhésion, Atomic force microscopy, Plasma, and Surface modification

The study investigated the use of dielectric barrier discharge for surface modification to improve adhesion properties of Shorea contorta (white lauan), Gmelina arborea (yemane) and Acacia mangium. Wood specimens were exposed to oxygen plasma at intensity levels ranging from 5.8 to 46.5 kW min/ m2 to improve adhesion of phenol formaldehyde, urea formaldehyde resins and polyurethane coating. Work of adhesion was calculated based on contact angle measurements to determine thermodynamic changes on plasma modified wood. Surface characteristic was evaluated using atomic force microscopy (AFM). Results of the study showed that plasma modification resulted in significant improvement in work of adhesion for the three wood species investigated. Mechanical tests of plywood and wood laminates using plasma treated S. contorta glued with phenol or urea formaldehyde resins indicated improvement in shear strength of adhesive joints. No improvement or decrease in shear strengths were observed for plasma treated G. arborea and A. mangium. Pull off strengths of polyurethane coating on plasma treated S. contorta and A. mangium specimens showed slight improvement in strength of coated film. Effects of plasma treatment on adhesion properties of wood appear to be species specific and vary with process parameters.

Metallurgy, welding, Métallurgie, soudage, Polymers, paint and wood industries, Polymères, industries des peintures et bois, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Physicochimie des polymeres, Physicochemistry of polymers, Industrie des polymeres, peintures, bois, Polymer industry, paints, wood, Technologie des polymères, Technology of polymers, Adhérence, Adhesion, Adherencia, Assemblage collé, Adhesive joint, Ensambladura pegada, Collage, Adhesive bonding, Enlace adhesivo, Joint recouvrement, Lap joint, Junta recubierta, Mouillabilité, Wettability, Remojabilidad, Oléfine polymère, Olefin polymer, Olefina polímero, Plasma, Polymère, Polymer, Polímero, Propriété surface, Surface properties, Propiedad superficie, Propène polymère, Propylene polymer, Propeno polímero, Préparation, Preparation, Preparación, Traitement surface, Surface treatment, Tratamiento superficie, Uréthanne polymère, Polyurethane, Uretano polímero, Adhésif structural, Travail adhésion, Atmospheric pressure plasma torch, Lewis acid and base, Polymeric surface preparation, Polypropylene, Primer, and Work of adhesion

The present work deals with the problematic adhesive bonding of substrates with low surface energy. Different approaches have been explored with the aim of creating adequate adhesive joints based on polyolefinic substrate and polyurethane adhesive. The selected material under study was polypropylene (PP) as adherend, and a commercial Sikaflex®―252 polyurethane one component based structural adhesive (PU) as joint fluid. Among the diverse pre-treatments typically used to prepare surfaces prior to bonding, mechanical abrasion with emery paper of 80 grain size, the use of a chemical primer and atmospheric pressure air plasma torch (APPT) were the selected methods to facilitate the application of the PU by means of surface energy enhancement as well as to create a correct mechanical interlocking of the adherent-adhesive interface. Changes in the wettability of the polymer were evaluated by contact angle measurements following the UNE EN 828:2010. Surface energy was calculated both in terms of Owens approximation and acid-base considerations, leading to the possibility of determining a relationship between changes in surface energy and adhesion. Changes in the chemical composition of the surface were studied by X-ray photoelectron spectroscopy (XPS), electron diffraction X-Ray (EDX) probe and attenuated total multiple reflection mode infrared spectroscopy (ATR-FTIR). Morphological modifications were investigated with scanning electron microscopy (SEM). Variations in the strength of single-lap PP-PP joints with the treatments were evaluated by lap shear tests following the UNE-EN 1465:2008 standard. Experimental evidence supports the superiority of the APPT treatment to increase wettability and adhesion of polyolefinic surfaces, especially when combined with the use of a primer.

Metallurgy, welding, Métallurgie, soudage, Polymers, paint and wood industries, Polymères, industries des peintures et bois, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Physicochimie des polymeres, Physicochemistry of polymers, Industrie des polymeres, peintures, bois, Polymer industry, paints, wood, Technologie des polymères, Technology of polymers, Adhésivité, Adhesivity, Adhesividad, Ester polymère, Ester polymer, Ester polímero, Ethylène téréphtalate polymère, Ethylene terephthalate polymer, Etileno tereftalato polímero, Plasma, Polymère, Polymer, Polímero, Propriété surface, Surface properties, Propiedad superficie, Rugosité, Roughness, Rugosidad, Thermoformage, Thermoforming, Formación en caliente, Traitement par plasma, Plasma assisted processing, Traitement surface, Surface treatment, Tratamiento superficie, Contact angles, Peel, Plastics, and Surface treatment by excited gases (e.g., flame, corona, plasma)

An atmospheric pressure plasma system has been used to treat amorphous polyethylene terephthalate (APET) to enhance its healseal properties to a polyethylene terephthalate (PET) film. The plasma treated APET sheet material was thermoformed into trays for use in the food packaging industry and heatsealed to a PET film. The heatsealing properties of the resulting package were assessed using the burst test technique. It was found that the plasma treatment significantly enhanced the adhesive properties and an increase in burst pressure from 18 to 35 kPa was observed for plasma treated food trays. The APET surface chemistry was assessed after plasma treatment where it was found that the plasma treatment had affected an increase in oxygen and an addition of nitrogen species to the polymer surface. The surface roughness (Ra) of the plasma treated samples was also observed to increase from 0.4 to 0.9 nm after plasma treatment.

Metallurgy, welding, Métallurgie, soudage, Polymers, paint and wood industries, Polymères, industries des peintures et bois, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Physicochimie des polymeres, Physicochemistry of polymers, Industrie des polymeres, peintures, bois, Polymer industry, paints, wood, Technologie des polymères, Technology of polymers, Adhérence, Adhesion, Adherencia, Agent accrochage, Coupling agent, Agente enganche, Matériau revêtement, Coating material, Material revestimiento, Paramètre interaction, Interaction parameter, Parámetro interacción, Polymère, Polymer, Polímero, Propriété mécanique, Mechanical properties, Propiedad mecánica, Propriété thermique, Thermal properties, Propiedad térmica, Propriété thermodynamique, Thermodynamic properties, Propiedad termodinámica, Renforcement mécanique, Strengthening, Refuerzo mecánico, Résistance traction, Tensile strength, Resistencia tracción, Silice, Silica, Sílice, Température transition vitreuse, Glass transition temperature, Temperatura transición vítrosa, Traitement surface, Surface treatment, Tratamiento superficie, Uréthanne polymère, Polyurethane, Uretano polímero, Adhesion by chemical bonding, and Interfaces, surface treatment

Surface treatment of nanosilicas with silane coupling agents is a common method by which the interfacial interaction of these particles can be enhanced. This is because of interactions taking place between the silane and silica, as well as the interactions between the organic part of the silane with the polymeric matrix. Therefore, interfacial interaction of silane grafted silica plays a key role to ensure a better reinforcing effect. The present work is an attempt to quantitatively predict the interfacial bonding strength between differently amino silane treated nanosilicas and a polyurethane coating matrix. This was based on the data deduced from tensile strength and dynamic mechanical thermal (DMTA) experiments of differently loaded untreated and treated nanosilicas loaded films. Using a predefined linear model taking into account the yield stresses of the particle loaded polyurethane and that of the matrix itself, an interaction bonding strength parameter was obtained. It was shown that this parameter was directly proportional to the amino silane content on nanosilica. However, for higher loadings of silicas the model best fit the data deviated from linearity and obeyed a second order equation, in which the second power term attributing the extent of interfacial strength was systematically increased. These results were in good agreement with the storage modulus and glass transition temperature values revealed by DMTA analysis.

Metallurgy, welding, Métallurgie, soudage, Polymers, paint and wood industries, Polymères, industries des peintures et bois, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Physicochimie des polymeres, Physicochemistry of polymers, Industrie des polymeres, peintures, bois, Polymer industry, paints, wood, Technologie des polymères, Technology of polymers, Acier inoxydable, Stainless steel, Acero inoxidable, Contrainte résiduelle, Residual stress, Tensión residual, Contrainte thermique, Thermal stress, Tensión térmica, Polymère, Polymer, Polímero, Propriété mécanique, Mechanical properties, Propiedad mecánica, Traitement surface, Surface treatment, Tratamiento superficie, Ténacité, Fracture toughness, Tenacidad, Fracture, Interfaces, Stress distribution, and X-ray diffraction measurement

The aim of this study is to investigate the effect of a stainless steel surface condition on the thermal residual stresses at a bi-material interface. AISI 304 stainless steel-epoxy specimens with either as-received, nitric acid etched or electropolished substrates were prepared. Exact specimen curvatures and an analytical method were used to estimate residual stresses and the behaviour of the epoxy layer. X-ray diffraction stress measurement (XRD) was performed to determine the interfacial stress state. In addition, a method was developed to examine the interface fracture toughness of the specimens. Based on the results, the residual stress estimation at the interface was confirmed and the effect of the surface treatments on the interface fracture toughness was evaluated.

Metallurgy, welding, Métallurgie, soudage, Polymers, paint and wood industries, Polymères, industries des peintures et bois, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Physicochimie des polymeres, Physicochemistry of polymers, Industrie des polymeres, peintures, bois, Polymer industry, paints, wood, Technologie des polymères, Technology of polymers, Acier inoxydable, Stainless steel, Acero inoxidable, Adhésif, Adhesive, Adhesivo, Coefficient dilatation thermique, Thermal expansion coefficient, Coeficiente dilatación térmica, Epoxyde résine, Epoxy resin, Epóxido resina, Matériau composite, Composite material, Material compuesto, Plasma, Polymère, Polymer, Polímero, Propriété mécanique, Mechanical properties, Propiedad mecánica, Propriété physicochimique, Physicochemical properties, Propiedad fisicoquímica, Propriété thermique, Thermal properties, Propiedad térmica, Résistance cisaillement, Shear strength, Resistencia cizallamiento, Stérilisation, Sterilization, Esterilización, Température transition vitreuse, Glass transition temperature, Temperatura transición vítrosa, Traitement surface, Surface treatment, Tratamiento superficie, Epoxy/epoxides, Glass, Steam sterilisation, and Structural acrylics

In order to assemble various multicomponent devices for biotechnological and endoscopic applications, the different parts are typically clamped or melted together. This, however, is complicated, time-consuming and often changes the actual geometry of the parts—thereby adversely affecting the reproducibility of experiments. Thus, the aim of this study is to investigate whether adhesives can replace these conventional glass joining techniques of melting and clamping in order to create durable and autoclavable devices of glass and glass/stainless steel parts that can withstand multiple sterilisation cycles. Twelve commercial acrylate and epoxy adhesives were screened for their capability to withstand 800 standard cycles of steam sterilisation. These adhesives were applied to different borosilicate, quartz and sapphire glass as well as stainless steel substrates pre-treated by either degreasing with 2-butanone or the surface was additionally modified by Pyrosil® or atmospheric plasma. The various physicochemical properties such as shear strength, maximum force at failure, extensibility and glass transition temperature of the best screened adhesives were examined. Furthermore, the surface topologies of the tested glass materials were characterised by Scanning Electron Microscopy (SEM). Finally, the shear strengths of the different bond combinations were quantified at 121 °C, the commonly applied sterilisation temperature in biotechnology. For every substrate combination, at least one adhesive was found, which created a durable bond capable of withstanding the maximum 800 autoclaving cycles. Here, the urethane acrylate GB 368 (Delo, Windach/Germany) was determined as the best adhesive to bond glass/glass and glass/stainless steel substrates. By comparison, the epoxy M-31 CL (Henkel-Loctite, Garching/Germany) showed comparable shear strength but only for glass/glass bonds. Most importantly, all the tested epoxy resins failed to bond glass with stainless steel. Unlike the acrylates, the epoxy adhesives displayed low extensibility. At 121 °C, the shear strengths of both the epoxy and acrylate adhesives were reduced by a factor of three to ten. Since all of the best screened acrylates proved superior extensibility, they can tolerate for the internal bond stresses resulting from different thermal expansion coefficients of glass and stainless steel. Consequently, they are the best adhesives to bond glass/glass as well as glass/stainless steel substrates for applications in biotechnology and medicine.

Metallurgy, welding, Métallurgie, soudage, Polymers, paint and wood industries, Polymères, industries des peintures et bois, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Physicochimie des polymeres, Physicochemistry of polymers, Industrie des polymeres, peintures, bois, Polymer industry, paints, wood, Technologie des polymères, Technology of polymers, Adhérence, Adhesion, Adherencia, Adhésif, Adhesive, Adhesivo, Biomatériau, Biomaterial, Dentisterie restauratrice, Dental restoration, Restauración dental, Matériau composite, Composite material, Material compuesto, Mode rupture, Fracture mode, Modo ruptura, Méthacrylate de méthyle polymère, Methyl methacrylate polymer, Metacrilato de metilo polímero, Polymère, Polymer, Polímero, Propriété mécanique, Mechanical properties, Propiedad mecánica, Résistance traction, Tensile strength, Resistencia tracción, Siloxane polymère, Siloxane polymer, Siloxano polímero, Traitement surface, Surface treatment, Tratamiento superficie, Résine dentaire, Composite, Denture, Soft liner, and Tensile bond

Silicone-based soft liners can be useful for patients who have difficulty to tolerate the hard-based dentures. However lack of adhesion to the denture base resin can be a problem that limits their clinical use. This study evaluated the tensile bond strengths (TBS) of four silicone soft liners (GC Soft, GC XSoft, Silagum, Mollosil) to two chemically different denture base resins, polymethyl methacrylate (PMMA) and urethane dimethacrylate (UDMA). Specimen consisted of soft liner material self-cured between two square plates of cured denture base resin measuring 20 x 20 x 4 mm. The circular bonding area of soft liner to each plate was 10 mm in diameter. Proprietary primer was applied to the surface of the denture base specimens before bonding following the manufacturers' recommendations. Ten specimens for each denture base-soft liner combination were prepared and tested under tension on a Shimadzu Universal Testing Machine at a cross head speed of 5 mm/min. The mode of failure was determined using a stereo-microscope at magnification of 10x. Two- and one-way ANOVA and post-hoc Dunnett-T3 and t-test were used for statistical analysis. There were significant differences in TBS values for the effect of denture base resins, soft liner and their interaction (p < 0.05). The TBS of soft liners to PMMA was significantly higher than to UDMA denture base resins except for Silagum where no significant difference was observed. A mixed mode of failure was more common for all soft liners bonded to PMMA except for Silagum while adhesive failure was more predominant in the UDMA group.

Metallurgy, welding, Métallurgie, soudage, Polymers, paint and wood industries, Polymères, industries des peintures et bois, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Physicochimie des polymeres, Physicochemistry of polymers, Industrie des polymeres, peintures, bois, Polymer industry, paints, wood, Technologie des polymères, Technology of polymers, Adhésif, Adhesive, Adhesivo, Assemblage T, T joint, Junta en T, Endommagement, Damaging, Deterioración, Morphologie, Morphology, Morfología, Mouillabilité, Wettability, Remojabilidad, Méthode élément fini, Finite element method, Método elemento finito, Polymère, Polymer, Polímero, Propriété surface, Surface properties, Propiedad superficie, Simulation numérique, Numerical simulation, Simulación numérica, Surface rupture, Fracture surface, Superficie ruptura, Traitement surface, Surface treatment, Tratamiento superficie, Modèle zone cohésive, Contact angle, Epoxy, and Fracture

In this work we investigate the effect of laser irradiation on the bond toughness of aluminum/epoxy bonded joints. The evolution of substrate surface morphology and wettability, for various sets of laser process parameters (i.e. laser power, line spacing, scan speed), was investigated by means of Scanning Electron Microscopy (SEM) and contact angle measurements. A proper combination of power, line spacing and scan speed was then selected and adhesive bonded Al/epoxy T-peel joints were prepared and tested. For comparison, similar samples were produced using substrates with classical grit blasting surface treatment. Finally, post-failure SEM analyses of fracture surfaces were performed, and in order to typify the increase in bond toughness of the joints, finite element simulations were carried out using a potential based cohesive zone model of fracture.

Metallurgy, welding, Métallurgie, soudage, Polymers, paint and wood industries, Polymères, industries des peintures et bois, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Physicochimie des polymeres, Physicochemistry of polymers, Industrie des polymeres, peintures, bois, Polymer industry, paints, wood, Technologie des polymères, Technology of polymers, Adhérence, Adhesion, Adherencia, Adhésif, Adhesive, Adhesivo, Adhésivité, Adhesivity, Adhesividad, Aluminium, Aluminio, Assemblage collé, Adhesive joint, Ensambladura pegada, Matériau renforcé dispersion, Dispersion reinforced material, Material renforzado dispersión, Polymère, Polymer, Polímero, Propriété mécanique, Mechanical properties, Propiedad mecánica, Propriété surface, Surface properties, Propiedad superficie, Propriété traction, Tensile property, Propiedad tracción, Résistance rupture, Rupture strength, Resistencia ruptura, Traitement surface, Surface treatment, Tratamiento superficie, Adhesive strength, Arcan test, Mixed mode, and Statistical analysis

This study aims at optimising adhesive properties in an aluminium/structural epoxy assembly for different conditions of surface pre-treatment. We consider the mechanical behaviour and failure under proportional, multi-axial loading using an instrumented, Arcan-type test. Values of fracture strength were found to be dispersed (even for a given surface treatment). Typically dispersion was of the order of 15%. This statistical behaviour, also observed with a simple tensile test, seems to be related to the heterogeneous nature of the microstructure of the adhesive bond, which contains voids, as well as mineral particles for reinforcement. A statistical analysis is suggested for use in conjunction with a strength envelope in practical design, for cases when the stress distribution is significantly heterogeneous. It is believed that this approach may be developed in order to understand the well-known scatter of adhesion strength results, and thus contribute to better reliability assessment.

Metallurgy, welding, Métallurgie, soudage, Polymers, paint and wood industries, Polymères, industries des peintures et bois, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Physicochimie des polymeres, Physicochemistry of polymers, Industrie des polymeres, peintures, bois, Polymer industry, paints, wood, Technologie des polymères, Technology of polymers, Acier inoxydable, Stainless steel, Acero inoxidable, Adhérence, Adhesion, Adherencia, Agent accrochage, Coupling agent, Agente enganche, Aluminium, Aluminio, Caoutchouc thermoplastique, Thermoplastic rubber, Caucho termoplástico, Cuivre, Copper, Cobre, Hydrolyse, Hydrolysis, Hidrólisis, Liaison hydrogène, Hydrogen bond, Enlace hidrógeno, Moulage injection, Injection molding, Moldeo por inyección, Mécanisme, Mechanism, Mecanismo, Oxyde de fer, Iron oxide, Hierro óxido, Polymère, Polymer, Polímero, Thermoplastique, Thermoplastics, Termoplástica, Traitement surface, Surface treatment, Tratamiento superficie, Uréthanne polymère, Polyurethane, Uretano polímero, Uréthanne élastomère, Polyurethane elastomer, Uretano elastómero, Vieillissement, Ageing, Envejecimiento, Aging, Plastic-metal hybrid, and Primers and coupling agents

The long-term properties of injection moulded metal―thermoplastic urethane (TPU) hybrids were studied. The hybrids manufactured with different metal substrates, namely copper, stainless steel and aluminium, were compared, using two surface modifications for copper and stainless steel. N-β-aminoethyl)-γ-aminopropyltrimethoxysilane was used as coupling agent. It is concluded that the bond mechanism of the silane on different substrate differs, affecting the long-term behaviour of the respective hybrids. The thick layers of silane coupling agent on copper and stainless steel are sensitive to hydrolysis; thus the resistance in humid conditions is quite low. The high temperature exposure increased the bond strength and the fraction of cohesive failure in TPU in copper―TPU, aluminium―TPU and polished steel―TPU hybrids. The last one has native mixed oxide, contrary to controlled oxidised stainless steel, where adhesion decreased after any long-term experiments. This is suggested to derive from hydrogen bonding of the coupling agent to the surface Fe2O3 oxide.

Metallurgy, welding, Métallurgie, soudage, 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, Domaines d'application, Application fields, 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, Chirurgie orl et maxillofaciale. Chirurgie dentaire. Orthodontie, Head and neck surgery. Maxillofacial surgery. Dental surgery. Orthodontics, Chirurgie maxillofaciale. Chirurgie dentaire. Orthodontie, Maxillofacial surgery. Dental surgery. Orthodontics, Adhésif, Adhesive, Adhesivo, Adhésivité, Adhesivity, Adhesividad, Agent accrochage, Coupling agent, Agente enganche, Biomatériau, Biomaterial, Dentine, Dentin, Dentina, Dentisterie, Dentistry, Odontología, Endodontie, Endodontic procedures, Endodoncia, Etude expérimentale, Experimental study, Estudio experimental, Matériau composite, Composite material, Material compuesto, Matériau renforcé fibre, Fiber reinforced material, Material reforzado fibra, Mode rupture, Fracture mode, Modo ruptura, Propriété mécanique, Mechanical properties, Propiedad mecánica, Propriété surface, Surface properties, Propiedad superficie, Résistance arrachement poussée, Push out resistance, Resistencia empujar, Silane organique, Organic silane, Silano orgánico, Traitement chimique, Chemical treatment, Tratamiento químico, Traitement surface, Surface treatment, Tratamiento superficie, Pivot dentaire, Adhesion by mechanical interlocking, Microscopy, and Surface treatment by chemical solutions

The effect of silane treatment on the push-out bond strengths of three different luting agents to fiber-reinforced composite (FRC) posts after thermocycling was evaluated. Sixty single-rooted human maxillary central incisors were sectioned below the cemento-enamel junction, and the roots were endodontically treated. RelyX Fiber Posts (size #2) were inserted using etch-and-rinse, self-etch, and self-adhesive luting agents (cementing agents). For half of the specimen in each group, the fiber posts were treated with a silane coupling agent. Bonded specimens were cut (2-mm-thick sections) and push-out tests were performed (crosshead speed, 0.5 mm/min). Failure modes were evaluated using a stereomicroscope at original magnification x 40. For each luting agent the use of silane did not result in any statistically significant difference at any level of the root compared to those of the control groups except for Variolink II and RelyX Unicem luting agents in apical root section (p < 0.05: one-way ANOVA). The post hoc analysis showed that regardless of the pre-treatment procedures, Variolink II achieved significantly higher bond strengths than Panavia F 2.0 and RelyX Unicem in all root sections (p < 0.05). The use of a silane coupling agent had no influence on bond strengths depending on the luting agent used, whereas the type of luting agent (etch-and-rinse, self-etch, and self-adhesive) appeared to be a significant influence on the push-out bond strength values independent of the pre-treatment used. Therefore, pre-treatment of fiber posts with a silane coupling agent does not seem to be mandatory, which saves time in the clinical situation.