Papers by Keyword: Silane

Abstract: Acrylic coatings were modified by adding 0.5 and 1.0% (v/v) of epoxysilane-treated (aluminosilicate, muscovite, nepheline syenite, and wollastonite) and alkoxysilane-treated (aluminosilicate) mineral fillers. Corrosion behavior of coated carbon steel specimens was studied using polarization method. Wetting behavior and adhesion of specimens were evaluated by static contact angle and cross-cut tape test. Addition of silane-treated mineral fillers dramatically improved the corrosion resistance of acrylic coating, with composite coating filled with alkoxysilane-treated aluminosilicate at 0.5% concentration showing significantly low corrosion tendency and rate in 2 M HCl solution. Contact angle also increased with the addition of fillers, with composite coating containing alkoxysilane-treated aluminosilicate at 0.5% yielding the highest mean value. Adhesion of acrylic coatings was enhanced after addition of fillers at 0.5%, with composite coatings filled with wollastonite and alkoxysilane-treated aluminosilicate giving the lowest percent area removed after application of adhesive tape. Alkoxysilane-treated aluminosilicate was found consistent in improving the anti-corrosion characteristics, water resistance, and adhesion to carbon steel of acrylic coatings.

Abstract: Continuous fibre reinforcements in thermoplastic composites require an enhanced adhesion to the matrix component, in order to effectively divert external forces from the matrix. Therefore different silanes as adhesion promoters are used as a part of the sizing. They operate as a connector to the matrix component. These silanes affect the sliding properties of the sizing during the production of the glass filaments in a negative way, in which case the proportion of the adhesion promoter in the sizing must be kept at a low level in order to maintain the processing speed in the textile production process. With the immersion bath method, it was examined whether the treatment of the surface of textile fabric after the textile production process with a silane-containing aqueous solution could solve these problems. Different silane concentrations and solvents were considered. After drying the textiles were processed during a two-step pressing process directly into a multi-layer organic sheet with a textile-based polypropylene matrix. The successful layering of the adhesion promoter on the glass fibre surface was verified by Fourier transform infrared (FTIR) spectroscopy. With thermogravimetric analysis (TGA), the thermal resistance of the adhesion-promoting layer for the subsequent pressing process could be shown. In order to examine the influence of the layer on the fibre/matrix adhesion within the composites, the Young’s modulus and flexural modulus of the composite panels were determined. Impact experiments were made to measure the required penetration energy and the energy absorption capacity of the composite panels. An optimum for the amount of adhesion promoter could be found. Exceeding the optimum amount of adhesion promoter in the solution led to a decrease in the mechanical properties of the composite.

Abstract: In this work we study influence of compatibilizers on tensile and rheological properties of new Silyl terminated polymer/Epoxy two component systems. In early works about that kind systems most of attention is devoted to polymers used (mainly silyl terminated polyether), while less attention is paid to catalysts, compatibilizers and additives [1-2]. One of the most important system elements are compatibilizers, while in this particular system silyl terminated polyether cannot react with epoxy groups directly. This work indicates that compatibilizer has a crucial meaning to reach material potential mechanical properties.

Abstract: The grafted materials of silaned-graphene oxide-mordenite (s-GO-MOR) were synthesized by grafting graphene oxide (GO) sheets to acid-treated mordenite and followed by functionalization with silane. GO sheets were prepared according to the modified Hummers method. 3-mercaptopropyltriethoxysilane (MPTES) was used as a silane coupling agent. The products were characterized by a Fourier transform infrared spectroscopy, X-ray diffraction, energy-dispersive X-ray spectroscopy and thermogravimetric analysis. The results confirmed the success of s-GO-MOR and showed excellent thermal stability.

Abstract: Hydrophobic surfaces are eyed for their self-cleaning ability because water droplets can roll on them (instead of clinging), thus the surface have capability to remove dirt. Hydrophobic surfaces were created by coating functionalized Titanium Dioxide-based paint. The paint was fabricated by reacting fluorosilane molecules in ethanol with titanium dioxide nanoparticles. Ethanol also serves as the volatile suspension medium that evaporates when the paint is coated on surfaces. The paint was coated on different surfaces by simple dipping. Contact angle of coated aluminum sheet, soda-lime glass, filter paper and silicon carbide polishing paper showed hydrophobicity. Water droplets are made to roll on coated soda-lime glass at angle of 0.057°. The ability of water droplets to roll highlights the coated surface self-cleaning potential.

Abstract: LBP has six steps, which are charging, exposure, development, transfer, fusing, cleaning and discharge, for the printing product. In these steps, we focused on the development step for the source of submicron inorganic pigments. The toner is a negatively charged combination of inorganic particles. A control blade holds the toner at a micro size distance from the drum. The inorganic pigment then moves from the control blade to the more positively charged latent image on the drum. The image in static electricity needs to be developed – made visible. The developer introduces small particles of toner onto the static-charged surface of the drum. In this study inorganic pigments were coated by functional silanes to provide particles with the electrostatic charge. The coating thickness and kinds of silanes were changed to evaluate the electrostatic charge of coated pigments. After coating process, the electrostatic charge of inorganic pigments coated with silanes were evaluated by the Faraday’s device. We will introduce the effect of 3-(N-phenylamino) propyltrimethoxy silane and phenyl tris (methylethylketoxime) silane coating on the electrostatic charge of inorganic pigments.

Abstract: Still more and more applications using synthetic polymers find new material alternative in materials based on synthetic polymer filled with nature fibers mainly plant fibers. Not only in common applications but also in technical applications is possible to use nature fiber composites. But some additional modifications are necessary to perform to gain properties possible to use in technical applications. Mainly increasing adhesion between matrix and fibers is the most common intent of these additional operations. This paper deals with maleic anhydride based coupling agent and silane coupling agent effect in the polypropylene matrix and jute fiber composite and its mechanical properties. By using of silane coupling agents was achieved mechanical properties which are possible to compare with composites with glass fibers mechanical properties mainly in case of the flexural and tensile modulus and mainly was gained significant increasing of composite production system stability.

Abstract: This study aims to investigate the properties of CDW recycled aggregates using silane-based water repellent agent in three different types of treatments: (a) immersion; (b) sprinkling; and (c) dripping; in order to improve the reduces quality of the material due to the high porosity. Wettability and water absorption were determined by apparent contact angle measurements, water absorption after 24h of saturation (standard method) and recording the variation of submerged mass during 24 hs. All treatment allowed reducing the water absorption and its kinetic. The contact angle measurements confirmed the effectiveness of the treatment: the surface resulted always hydrophobic. Comparing the treatments, immersion gave the best result in terms of absolute results and in terms of variability of measurements.

Abstract: Rapid prototyping (RP) is a new technology to fabricate a prototype part layer-by-layer. This technique has been achieved in many industrial sectors, but parts fabricated using this technique exhibit low mechanical properties, this makes it difficult to apply to fast growing applications. This technology can not only effectively save production time and cost of the prototypes, but also produce complicated product. In this study, we investigate the effect of the addition of halloysite nanotubes on mechanical properties of nanocomposites made by the RP process. Test specimens were fabricated using tetrafunctional polyester acrylate (TPA) and 1, 6 hexanediol diacrylate (HDDA) photopolymer as a matrix material and halloysite nanotubes as a reinforcing material. The adhesion between TPA/HDDA and halloysite nanotubes has been improved by using surface modification of a silane coupling agent. When compared with neat photopolymer, the tensile strength of nanocomposites decreased by about 22%, because the halloysites had poor interfacial adhesion. Silane treatment of halloysites using 3-aminopropyl triethoxysilane was succeeded to improve tensile strength of nanocomposites (2 phr halloysite nanotubes) by 31%.

Abstract: This research fabricated hydrophobic surfaces of aluminium alloy via electrochemical anodization and silane coating. The procedures consisted of electrochemical anodization in 1 and 1.5 M sulfuric acid using 12 volts dc. Anodization produced stable porous oxide layer on the surface. Aluminium alloy formed porous oxide structures with thickness in micrometer regime. The thickness of the porous layer was affected by the anodizing conditions such as electrolyte concentration and time. Dichloro methylsilane (5% in ethanol) was applied onto the porous surfaces by submerging the anodized surfaces into it for 10-60 min. After washing the treated surfaces with soap for many times, hydrophobic surfaces were obtained with some surfaces showed wetting angles greater than 100°. Water droplets of any sizes can roll off on these surfaces when tilted at angles above 10°. The treated aluminium surfaces can be applied for self-cleaning and anti-icing applications.