Papers by Keyword: Silane

Abstract: This study focuses on the influence of soybean oil (SO) modified by TESPT silane coupling agent as an environmentally friendly processing oil on the properties of the silica-reinforced rubber compounds. A proton nuclear magnetic resonance (¹H-NMR) spectroscopy confirmed that a novel processing oil based on silane-modified SO was successfully prepared in the laboratory. It was found that the unsaturated structures in SO reduced after modification. The properties of the rubber compounds with different types of processing oils were investigated by comparison to the rubber compound without processing oils. The addition of processing oils into the rubber compounds reduced filler-filler interactions within the rubber matrix due to a shielding effect of silica surfaces by processing oils. The silane-modified SO could react with the silanol group on the silica surfaces, leading to a hydrophobicity of silica surfaces. So, the use of silane-modified SO showed lowest filler-filler interactions. In addition to the filler-filler interactions, the presence of processing oils in the rubber compounds reduced the viscosity of the materials as indicated by minimum torque received from a cure curve. The levels of filler-filler interactions in the rubber compounds correlated well with the viscosity. The crosslinking points within the rubber matrix of the oil-added compounds were lower than the one without processing oil. Furthermore, the mechanical properties of the rubber compounds with and without processing oils were considered. The processing oils did not affect the tensile strength, but strongly improved elongation at break.

Abstract: In this study, an eco-friendly coconut oil-based polyol blend was synthesized for bio-based waterborne polyurethane (WBPU) and WBPU-silane composite coatings. It was demonstrated that an increase in silane content incorporated into the WBPU matrix significantly enhanced the corrosion protection of WBPU coatings. Results also show a fourfold increase in the adhesion strength of WBPU-silane composite coatings as compared to that of bare WBPU coatings. Further, the water contact angle revealed that hydrophobic properties increase as the silane content incorporated into the WBPU matrix increases. This work provides a novel route for enhanced corrosion protection utilizing a bio-based polyol blend.

Abstract: The use of leaflet ribs from oil palm trees - Oil Palm Broom Fibres (OPBF) in reinforcingcement composites have shown some prospects according to recent studies. However, only little isunderstood regarding their bond interaction with cement matrices. Samples were prepared toinvestigate the pull-out response of OPBF in both single and combined form from concrete. For thecombined fibres, single OPBF strands were wound around one another longitudinally (in helical form)to form tendons. A comparison was made between the maximum bond strengths of untreated andtreated OPBF in concrete. The OPBF were pre-treated by soaking in sodium hydroxide andtriethylvinylsilane solutions to improve their bond strength with concrete. The reported treatmentscould improve the potential of OPBF tendons as reinforcement in lightly loaded concrete beamsultimately resulting in an environmentally friendly and affordable construction.

Abstract: Epoxysilane-treated muscovite (ETM) was used as reinforcing filler to 3D-printed acrylonitrile butadiene styrene (ABS) via fused deposition modeling (FDM). Its effects to the mechanical and thermal properties of ABS were investigated. ETM was loaded at 1, 3, and 5wt%. ABS/ETM composites were characterized via scanning electron microscopy (SEM), tensile test, differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). Mechanical reinforcement of ABS was observed for ABS/ETM composites loaded at 1 and 3 wt% wherein it was noted that the tensile strength and elastic modulus increased by up to 83.6% and 76.6%, respectively. Reinforcement was brought by interfacial adhesion of ETM with the ABS matrix. There was a sharp decline in mechanical properties for ABS/ETM composites loaded at 5wt% due to agglomeration of ETM in the matrix and discontinuities in the printed layers. The glass transition temperature (T_g) of ABS increased and the onset of its degradation shifted towards higher temperatures with the addition of ETM. It can be concluded that the addition of ETM to ABS for FDM 3D printing improved its mechanical and thermal properties.

Abstract: Silica aerogel is a nanostructured porous solid material. It has a low bulk density, low thermal conductivity and can be hydrophobic. In this work, hydrophobic silica gel, a material used to form aerogel, is used instead of its powder form to avoid ultrafine air particles pollution. It is used to surface modified materials to make the materials superhydrophobic and still withstand physical abrasion that ordinary aerogel would not able to do. The superhydrophobic silica aerogel coating was designed by mixing the hydrophobic gel with DOW CORNING^® 2405 resin as binder and varying DOWSIL^™ Z-6137 silane and tetraethyl orthosilicate (TEOS). The coating is characterized by the static contact angles (CA) and abrasion test. Scanning electron micrographs of different coating compositions were investigated. Results show that the hydrophobic gel mixed with resin and Z-6137 silane have contact angle >179º. Superhydrophobic silica aerogel coating can be utilized as material coatings for glass, fiber, polymer, etc.

Abstract: The aim of the research is to subject the three different silanes to chemical and electrochemical investigations in other to determine the most efficient organic compound. Three types of hydrophobic silanes [Tris (Trimethylsiloxy) silyethyl] dimethylchlorosilane (Alkyl); Tridecafloro-1,1,2,2-tetrahydrooctyltrichlorosilane (FOTS) and Henicosyl-1,1,2,2-tetrahydrododecyltricholrosilane (FDDTS) are presented and investigated. The three silanes are of different composition but are deposited at the same parameters and conditions. The chemical investigation was studied through (attenuated total reflection Fourier-transform infrared (ATR-FTIR) and x-ray diffraction (XRD), while the electrochemical study was conducted through EIS using natural seawater electrolyte at room temperature. From the investigation techniques, only electrochemical impedance results show that FDDTS performed better than both Alkyl and FOTS. The chemical analysis showed the presence of hydrophobic silane on all the coated samples, and no distinction can be drawn from associated peaks.

Abstract: This work aims to evaluate the influence of the alkoxy precursor concentration on the morphological and electrochemical characteristics of the chemical conversion layer formed on a galvanized steel surface. Different films were obtained by the dip coating method varying precursor concentrations in 2, 5 and 10%. According to the SEM and EIS results the corrosion resistance property increases for higher GPTMS precursor concentrations.

Abstract: The present work aimed at incorporating the rice hull ash (RHA) into a polypropylene polymer matrix. The methodology applied was the case study, whereby the rice hull, residue generated during the grain extraction, was used in the present study. The samples were prepared with the addition of a coupling agent (silane) with 10% by mass in relation to the filler, to improve the characteristics of the ash/ matrix interface. The tensile test results showed that the modulus of elasticity increased proportionally to the addition of the RHA contents, promoting an increase in the material stiffness. The micrographs showed excellent adhesion between the RHA particles and the polymer matrix. proving the coupling, because there was a good wettability array load due to the use of the coupling agent. The results show the feasibility of use of CCA in the composite with PP.

Abstract: Surface treated parawood microcrystalline cellulose (PW-MCC) performed under mechanochemical reaction using planetary ball milling at ambient temperature was used as a reinforcing material in polypropylene composites. Initially, PW-MCC was prepared by acid hydrolysis of parawood sawdust pulp. After that, PW-MCC was treated with vinyltrimethoxysilane at milling speed 400 rpm for 60 min. The surface composition from XPS indicated the existence of silicon atom on silane-treated PW-MCC. The thermal stability of PW-MCC was also improved and SEM micrograph revealed rough surface after modification reaction. The untreated PW-MCC and treated PW-MCC were applied to prepare polypropylene composites at 5-30 wt% loading content without a compatibilizer. The results demonstrated that silane-treated PW-MCC/PP composites enhanced tensile strength, thermal stability and water resistance of the composites.

Abstract: Saturated polyester (PE) resin was modified with 0.5 and 1.0% (v/v) of epoxysilane-treated (aluminosilicate, muscovite, nepheline syenite, and wollastonite) and alkoxysilane-treated (aluminosilicate) mineral fillers before coating to carbon steel. The corrosion behavior of specimens was studied using potentiodynamic polarization method. Wetting behavior and adhesion of specimens were evaluated by static contact angle and cross-cut tape tests, respectively. The addition of silane-treated mineral fillers dramatically improved the corrosion resistance of saturated PE, with epoxysilane-treated wollastonite and alkoxysilane-treated aluminosilicate at 0.5% concentration significantly lowering the corrosion tendency and rate in 2 M HCl solution. Meanwhile, only epoxysilane-treated nepheline syenite significantly increased the water contact angle of saturated PE. The adhesion of saturated PE to carbons steel was increased after addition of fillers at 0.5%, with epoxysilane-treated wollastonite and alkoxysilane-treated aluminosilicate giving the lowest percent area removed after application of adhesive tape. Epoxysilane-treated wollastonite and alkoxysilane-treated aluminosilicate at 0.5% were found most suitable as fillers for saturated PE coating.