Potassium Methyl Siliconate Research Articles

Novel application of potassium methylsiliconate in cement-based materials: Retarding of hydration process and improvement of compressive strength

The presented research investigates the application of the organosilicon compound named potassium methylsiliconate (MESI) as a set-retarding admixture for cement-based materials which also provides the strengthening effect. The study concerns the impact of three dosages of MESI (1%, 2% and 3% per cement mass) on the properties of the cement paste, mortar and concrete. The greatest delay of the setting time of cement CEM I 42.5 R and retardation effect, examined by manual Vicat apparatus, was observed for addition of 1% methylsiliconate. The beginning of the setting was prolonged to 23 h. The influence of potassium methylsiliconate on the kinetics of cement hydration was investigated by isothermal calorimetry. The calorimetric results disclosed significant extension of induction period during Portland cement hydration with addition of potassium methylsiliconate as an admixture. It is especially visible in case of addition of 1% of MESI. Moreover, tests performed at 30 °C, 40 °C and 50 °C showed that MESI can also delay the cement hydration at higher temperatures. The influence of potassium methylsiliconate on the compressive strength of cement mortar and concrete after 1, 2, 7, 28 days and72 days was also investigated. In the first days of hydration, the compressive strength of the materials was reduced, but after 28 days of curing the compressive strength was increased by 21% and 16% for cement mortar and concrete, respectively. The impact of MESI on the microstructure and pore size distribution of cement pastes in 2nd, 7th and 28th of hydration was examined by mercury intrusion porosimetry (MIP). The result showed significant delay in the development of the cement pastes microstructure during the first days of hydration. The XRD and DTA/TG analysis provided the knowledge about impact of siliconate on the composition and formation of the cement phases. Both, the XRD and DTGA/TG analyze showed noticeable changes in portlandite formation during the first days of hydration. The conducted research and obtained results reveal the innovative and novel application of potassium methylsiliconate as retarders, which prolongs the workability of fresh mixture and improves the compressive strength of matured concrete and mortar. This admixtures can be a competitive alternative to traditional retarders.

Novel prepared nano potassium methyl siliconate as antioxidant for nitrile rubber

In this work, novel potassium methyl siliconate (PMS) was employed as a new nano-type antioxidant for acrylonitrile-butadiene rubber (NBR). NBR/PMS composites were produced by incorporating various contents of the prepared compound as anti-ageing agents (PMS) to improve the heat resistance of these composites. Potassium methyl siliconate (PMS) was prepared, and its chemical structure was confirmed by different elemental analyses. The curing properties, filler dispersion, thermo-oxidative ageing test, mechanical properties, FTIR, and TGA of the NBR/PMS composites were evaluated. It was detected by TEM images of PMS. The particles had a rhombic shape, and the particle size ranged from 1.23 nm to 7.84 nm. PMS could successfully promote the interfacial interaction between rubber and filler and the uniform dispersion of silica particles into the NBR matrix. As a result, the mechanical characteristics of the NBR/PMS composites were significantly improved, and they were superior to those of the NBR/TMQ composites with similar filler contents. Furthermore, the crosslinking density of the NBR composites was reduced after adding PMS (an antioxidant), which had a great effect on the mechanical properties. The results exhibited that PMS dramatically enhanced the solvent extraction resistance and the thermo-oxidative ageing resistance of NBR/silica composites more efficiently than TMQ. Overall, this work extended the application scope of PMS to develop novel and effective antioxidants for elastomers.

Effects of Nanomaterials on Engineering Performance of a Potassium Methyl Siliconate–Based Sealer for Cementitious Composite

Effects of Nanomaterials on Engineering Performance of a Potassium Methyl Siliconate–Based Sealer for Cementitious Composite

Influence of organosilicon admixtures on the hydration of Portland cement

AbstractThe impact of three different organosilicon compounds: poly(dimethylsiloxane) (PDMS), potassium methylsiliconate (MESI) and triethoxyoctylsilane (OTES), used as integral admixtures, on Portland cement hydration has been investigated by isothermal calorimetry and DTA-TG analysis. The silicon-based compounds are widely used as internal hydrophobic agents added into batch water; therefore, their effectiveness was investigated by means of capillary water absorption test. The isothermal calorimetry was used to measure the rate and amount of heat released during ordinary Portland cement hydration with integral organosilicon admixtures at 20 °C, 30 °C, 40 °C and 50 °C. It allowed to determine the activation energy as well. The results indicate that used admixtures (except MESI admixture) decrease in the rate and amount of heat release during cement hydration. In addition, it is noticeable that the addition of MESI admixture significantly prolongs the induction period and delays hydration. In contrast to MESI and OTES admixtures, PDMS-based admixture does not affect significant on the activation energy. DTA-TG analysis had shown differences between reference sample and samples containing organosilicon admixtures during thermal decomposition, in terms of the amount of moisture and bound water, as well as Ca(OH)2or carbonates. The results presented in this paper enable a better understanding of the interactions between the organosilicon integral admixtures and the cement matrix. The study shows the effect of integral admixtures on cement hydration and thus the potential effect on the final properties of the cement-based material.

Preparation, Surface Characterization, and Water Resistance of Silicate and Sol-Silicate Inorganic-Organic Hybrid Dispersion Coatings for Wood.

The purpose of this study was to comparatively investigate the behavior of silicate and sol-silicate coatings non-modified or modified with an organosilane on wood and on wood pre-coated with silica-mineralized primers. Adhesion strength, morphology, and water permeability and related damages were studied to evaluate the possibility of utilizing such inorganic-based coating systems for durable protection of wood without or with relatively cheap and water-borne primers. Potassium silicate and potassium methylsiliconate aqueous solutions and a colloidal silica were used for the preparation of the coatings. The white coating paints were brushed on beech wood substrates at a rate of 220 g·m−2. The coatings exhibited good coverage ability. The pull-off adhesion strength values appeared to be related to pH following a polynomial law. The adhesion strength for the silicate coatings were adequate (above 3 MPa and up to 5 MPa) for wood, whereas the values for the sol-silicates were too low for practical applications. The adhesion values were in general higher for the samples cured in a climate room (23 ± 3 °C and 75 ± 2% relative humidity) than the samples cured in the ambient atmosphere of the laboratory (23 ± 3 °C and 25 ± 5% relative humidity). The presence of microdefects (cracks, holes) was revealed in the coating layers by optical and scanning electron microscopy. The surface roughness parameters assessed by confocal scanning laser microscopy were dependent on the magnification applied for their measurement. The arithmetic average roughness Sa was between 5 µm and 10 µm at magnification 5× and between 2.5 μm and 10 µm at magnification 20×. The maximum peak-to-valley height Sz confirmed the presence of open pores emerging through the coatings. The open pores constitute free pathways for water ingress through the coatings, and could explain the high water absorption of the coatings including the methysiliconate-containing silicate coating and despite the relatively high water contact angle and low wettability exhibited by this sample. The post-application of a hydrophobizing solution containing hexadecyltrimethoxysilane and dimethyloctadecyl[3-(trimethoxysilyl)propyl]ammonium chloride considerably reduced the water permeability, while application of nanosilica-containing organic primers increased the adhesion for the coatings. Silicate coatings with adhesion great enough and resistance against water damages can be generated on wood even without a primer using low silica-to-alkali ratio binders and an organosilane additive. The sol-silicate coatings appear to be applicable only with a primer. The improvement of the paint formulations to control the formation of microcracks and open pores could be useful to reduce the liquid water permeability and increase durability. Otherwise, the application of a hydrophobizing treatment can be used for this purpose.

Study of the Adhesion of Silicate-Based Coating Formulations on a Wood Substrate

Silicate coatings are environmentally friendly inorganic-based products that have long been used for mineral substrates and protection of steel against corrosion. The development and acceptance of these coatings in the wood sector require some adjustments in formulations or special preparation of the surface to be coated to obtain durable finishes. In this work, the adhesion of various silicate-based formulations to a beech wood substrate (Fagus sylvatica L.), was assessed with the main objective to study relevant parameters and potential improvements. Adhesion strength was determined by pull-off and cross-cut tests. Other coating properties such as scratch, impact, and water resistance were also determined. Surface roughness and interface were analyzed using confocal laser scanning microscopy (CLSM) and scanning electron microscopy (SEM), and coating curing was studied by attenuated total reflection-infrared spectroscopy (ATR FTIR). The results showed that adhesion was highly dependent on formulation, penetration of the coatings into wood, and mechanical anchoring. Increasing the content of solid particles in the coating formulations or adding a polyol (glycerol, xylose), which probably acted as a coalescent, considerably decreased the adhesion strength, probably by blocking penetration into the wood by forming aggregates. Adhesion was improved by pre-mineralization of the surface, and substitution of a part of the potassium silicate binder with potassium methyl siliconate reduced the formation of cracks caused by dimensional instability of the wood.

Development of a transparent silica-titania-methyl siliconate nanocoating with photocatalytic-hydrophobic properties aided by response surface method

This work aims to optimize the factors affecting silica-titania-methyl siliconate photocatalyst hydrophobic coatings prepared through a straightforward chemical method using tetraethyl-orthosilicate (TEOS: C8H20O4Si), tetraethyl-orthotitanate (TEOT: C8H20O4Ti) and potassium methyl siliconate (PMS: CH3SiO3K3). Field Emission- Scanning electron microscopy (FE-SEM) images showed that a uniform and crack-free coating with a thickness of nearly 90 nm was formed on the surface at the low temperature. FT-IR spectroscopy confirmed the formation of silica and titania particles on the coating. Response Surface Method (RSM) with 29 experiments was implemented, and the contact angle with photocatalytic efficiency was considered as the response to be optimized. Four effective factors of the mole ratio of TEOT/TEOS, PMS/TEOS, H2O/TEOS, and pH were determined in three levels, which were equal to 35, 0.06, 5.5, and 2, respectively, obtained by an Analysis of Variance (ANOVA) over the experiment results. In the mentioned conditions, the expected result for the contact angle and photocatalytic efficiency were 139˚ and 43.5%, respectively, and the confirmation test reached 141° and 41%. Consequently, TEOT/TEOS and PMS/TEOS molar ratios were found to be the most effective factors in both photocatalytic and hydrophobicity of the coating.

Investigation of the efficiency and potential possibilities of paper protection by siloxan in wet environments

The object of research is unbleached pulp-based winding with a thickness of 70±3 μm. One of the main problems is the use of the research object as a packaging material. Particular attention is required to protect paper when it is used in wet conditions. The presence of a layer of adsorbed water on the surface can adversely affect the physical and technical properties. The degree of such influence is determined by the energy state of the surface of the substrate and by the wettability of its water in the liquid-crystal state and the adsorption of water vapor. To ensure the stability of this paper in aggressive media, its modifications are carried out by immersion in 3–5 %, by volume of the solution in water, organic solvents or an aqueous dispersion of organosilicon products. A study of the hydrophobic properties and the mushroom resistance of the surface of the treated paper is also carried out. The results of the investigation of the tensile strength and dielectric parameters of the treated paper are considered. For comparison, IR spectrometry of porous aluminosilicate glass is carried out. One of the main criteria is the tensile strength of the investigated paper treated with silicone coatings. As a result of the conducted studies, it is found that a less tensile force at the level of 84.6–90.1 % of the initial one is fixed when using coatings based on potassium methyl siliconate and its derivatives in various combinations. Therefore, in comparison with untreated paper, the modified one acquires high performance properties in terms of protection in humid environments.

Investigation of the modification process of natural sedimentary calcite by organosilicon compounds

The object of this research is the process of natural sedimentary calcite modification. The main problems that are solved in this research are the choice of the most suitable low molecular weight modifier among potassium methylsiliconate, sodium methylsiliconate and polymethylhydride siloxane, as well as the selection of optimal grinding regimes for the raw mineral. It is found that during the mechanochemical activation in the presence of organosilicon modifiers, hydrophilicity coefficient of the surface of the sedimentary chalk is significantly reduced. The most effective modifier for the surface of sedimentary calcite is polymethylhydride siloxane. It is established that in the presence of modifiers, grinding and amorphization of carbonate raw materials are activated, which is confirmed by a decrease in the intensity of calcite reflections to 9 % in the case of the use of polymethylhydride siloxane and by 5–7 % in the case of methyl siliconates. It is shown that the modification of the sedimentary chalk surface leads to a decrease in the capacity of its adsorption layer by 20 % of the capacity of the processed material. The strength of the coagulation structure in the filler-film former system also decreases: the yield point of the system with untreated material is 20 % higher than this limit for the system where chalk is modified with polymethylhydride siloxane. Despite the advantages of the proposed technical improvement, it is likely that the use of traditional fatty acid-based materials will remain more attractive in continuous production. Since this method has advantages from the point of view of the absence of the need to change the existing composites formulations, and from the point of view of minimizing the cost price. Research results will be more interesting in those industries where improving the properties of the material plays a decisive role.

Thermal analysis and IR-spectroscopic research into interaction between organosilicon compounds and nonmetallic materials

It is established that the treatment of carbonate and silicate nonmetallic materials with organosilicon compounds is accompanied by the occurrence of endothermic and exothermic effects. Exothermic effects are associated with the cleavage of radicals in the organosilicon compounds. It was found that the tuff impregnated with ethyl silicate hydrolyzate is characterized by a wider range of removal of radicals – С 2 Н 5 . This may be due to their more intense interaction as compared to other non-metallic materials. Occurrence of endothermic effects is caused by release of water, which formed as a result of interaction between nonmetallic materials and organosilicon compounds. The strength of bond between organosilicon compounds and non-metallic materials decreases in a series of sodium phenyl siliconate>potassium methyl siliconate>sodium ethyl siliconate. An interaction between siliconates of alkali metals and silicate non-metallic materials is characterized by a stronger bond than that in the case of carbonate materials. The total loss of mass of impregnated silicates is 5.4–10 % versus 26.1–30.3 % in carbonates. The data on IR spectroscopy of the impregnated nonmetallic materials also testify to the physical-chemical interaction between carbonates and silicates and organosilicon compounds. The fixation and interaction of siliconates in the composition of carbonates is evidenced by the occurrence on IR spectra of new bands at 2900–3000 cm –1 and an increase in the intensity of bands responsible for oscillations in the bonds between silicon and oxygen. The evidence of this is also an increase in adsorbed water and a decrease in the intensity of absorption bands characteristic of anion There is also an expansion in the range of bands responsible for the valence and deformational oscillations in the bonds between silicon and oxygen. There appear the bands that are caused by the deformational oscillations in the bond between C–H and adsorbed water. The indicated peculiarities allow us to conclude that in the structure of silicates and carbonates there occurs both a physical fixation and a chemical interaction between siliconates of potassium and sodium.

Analysis of the effect of chalk modification on the peculiarities of its interaction with acrylic film former

We performed analysis of the processes of interaction in the systems of chalks with a modifier (potassium methylsiliconate) and acrylic film forming material. The studies were conducted with the help of infrared spectroscopy. The purpose of the work was to estimate the level of development in the processes of interaction in the examined systems. Quantitative parameters of the basic characteristic bands in charge of the valence vibrations of reactive groups of chalks and film forming agent are determined. The shifts in characteristic bands of the IR spectra, changes in their intensity are indicated. The results of present work testify to the fact that in the systems chalk – potassium methylsiliconate – acrylic film forming agent, the processes of interaction proceed with the participation of adsorbed water, bonds C=O and C–O of chalks. We also noted intensive inculcation of polymer (by the intensity of bands characteristic for the С–Н bonds) by 2–8 times with the use of modified chalks in comparison with the starting ones. An increase in the interaction between chalks and the film-forming agent by the modification of this filler is of interest for creating functional composite materials as it provides for an improvement in their properties.

PHYSICAL AND CHEMICAL FUNDAMENTALS OF PROTECTION PROCESSES FOR SURFACE LAYER OF CONCRETE ROAD PAVING BY IMPREGNATING COMPOSITIONS

Construction of concrete road paving which was started in the 30-ies of the last century in the United States has proved its perspectiveness from the viewpoint of service life. In addition to that an analysis of road usage has shown that concrete paving is a deformation tendency due to some reasons and the tendency entails some difficulties in their repair after rather long operation. The deformations appear more intensively after 5-10-year road operational period. The following negative effects are practically unavoidable: micro-crack formation, scaling, deformation due to freezing of angular edges in concrete plates, destruction of deformation joints etc. The defects are characterized by rather large scope and they are present practically on all the roads. It is necessary to note the fact that a great number of the above-mentioned defects can be avoided on the condition that measures on strengthening surface layer of concrete paving will be undertaken in time. The measures presuppose application of impregnating method while using compositions that contain hydrophobisator and silicon dioxide sol. Industry-produced potassium methyl siliconate, oligomethyl hydride siliconate, tetraethoxysilane have been used as hydrophobisator and they form not easily soluble film on the surface of concrete pores which prevents penetration of water into concrete. Calcium hydrate being formed in the dissolution and hydrolysis process of cement clinker minerals is bound in hydrosilicates which are contained in the solution impregnated by silicon dioxide sol. These hydrosilicates culmatate concrete pores and strengthen its surface layer due to additional hard phase and according to chemical composition it is related to calcium hydrosilicates formed as a result of concrete hardening.

Fire retardant finish of jute fabric with nano zinc oxide

Nano zinc oxide (ZnO) was applied on bleached jute fabric to impart fire retardant finish. Nano zinc oxide was prepared from aqueous Zinc acetate by co-precipitation method in the presence of NaOH followed by calcination at 600 °C. It was then applied on the jute fabric using an aqueous solution of Potassium Methyl Siliconate as dispersing media by pad-dry method. Among different dosages of nano ZnO treatment, application of a 0.01% nano ZnO on jute fabric showed reasonably good fire retardant performance. Nano ZnO powder so produced was characterized by confirming particle size and its distribution along with XRD. Nano zinc oxide particles coating on treated jute fabric was evidenced by FTIR, EDX, AAS and SEM analysis. Analysis of physical properties of the coated jute fabric has shown some extent of reduction in fabric tenacity, whiteness index and increase in stiffness as compared to untreated bleached jute fabric. The coating had reasonably good LOI values for as many as five wash cycles.

Chemical investigation of potassium methyl siliconate as deacidification and strengthening agent for preservation of aged papers

Potassium methyl siliconate (PMS) was investigated as a simple physicochemical modification in aged paper using silane coupling technique. The PMS-based solution was shown to favor penetration in the cellulose fibers on the paper with suitable uptakes being achieved at low concentrations. The studies of the physicochemical properties of the treated paper (mechanical strength and alkalinity) demonstrated that, besides the required deacidification feature and high level of alkali reserves, the immersion treatment by PMS allowed the enhancement of the mechanical intensities of paper arising from the interaction between Si―OH generated in hydrolysis of PMS and C―OH of cellulose on the paper. Adding ethanol into PMS solution could significantly improve mechanical properties of the aged paper treated by the formula apart from modifying the flatness of the paper. Optimized treatment process was achieved by altering the ratio of ethanol to water in PMS-based solutions. Contact angle measurements indicated the occurrence of hydrophobic character of the papers in immersion treatment with PMS-based solutions. The easy availability of the materials and simplicity of the method rendered it convenient for treatment for aged paper documents.

Inhibitive effect of potassium methylsiliconate on hydration swelling of montmorillonite

Herein we report on a study on the inhibition effect of potassium methylsiliconate on hydration swelling of montmorillonite. The results of linear swelling tests showed that potassium methylsiliconate exhibits a high performance as an effective shale inhibitor in drilling fluids. The inhibition mechanism was investigated by means of a variety of methods including Fourier transform infrared spectroscopy, X-ray diffraction, transmission electron microscopy, and zeta potential measurements. The high degree of inhibition is a result of the synergy of action of potassium cations and methylsiliconate anions. Methylsiliconate anions form a hydrophobic shell around each montmorillonite particle through the adsorption on the edge sites, thus inhibiting the penetration of water into the interlayer. The potassium ions promote the formation of a less hydratable structure of montmorillonite through cation-exchange interaction.

Inhibitive Effect of Potassium Methylsiliconate on Hydration Swelling of Montmorillonite

Inhibitive Effect of Potassium Methylsiliconate on Hydration Swelling of Montmorillonite

Dimensional stability of wood–plastic composites reinforced with potassium methyl siliconate modified fiber and sawdust made from beetle-killed trees

Wood from two varieties of beetle-killed trees was used to fabricate wood–plastic composites. Loblolly pine and lodgepole pine beetle-killed trees were defibrated mechanically and thermomechanically, respectively, into fiber. Fiber and sawdust produced from the trees were modified with potassium methyl siliconate (PMS) and injection-molded into fiber/sawdust reinforced plastic composites. Modification of fiber and sawdust with PMS improved the compatibility between lignocellulosic materials and ethylene plastic in the composites, resulting in decreased water sorption, increased dimensional stability, and increased tolerance to morphological variations in the fiber and sawdust. Fiber-to-sawdust ratio and size of sawdust particles affected the time required for saturation with water, as well as dimensional stability.

Synergistic effect of potassium metal siliconate on silicate conversion coating for corrosion protection of galvanized steel

Silicate conversion coating is considered as an alternative to hexavalent chromium conversion coating for corrosion protection of galvanized steels. However, the coating must be treated with hot air afterward in order to obtain a water resistant silicate layer and to increase corrosion resistance of the coating. Moreover, it is difficult to apply the uniform thermal treatments on the large irregular shaped metal parts. Furthermore, the heat treatment is an energy consuming process. In this work, the effects of adding potassium methyl siliconate (PMS) into the silicate conversion coating on the anti-corrosion properties were studied. The silicate coating layers were formed by the simple immersion into the silicate solutions and the subsequent ambient drying at room temperature. It was verified that the addition of PMS increased the temporary corrosion protection ability without the post-thermal treatments. Coating thickness was around 100nm and K ion was distributed preferentially at zinc-silicate interface. It was proved that the more hydrophobic surface was formed mainly due to the substantial decrease of the concentration of K ion at the coating surface by the addition of PMS. It was a methyl group of PMS that changed the hydrophilic silicate layers into hydrophobic ones. Subsequently, the enhanced water barrier property of the hydrophobic silicate layers increased the corrosion resistance of the silicate-coated galvanized steel.

Fabrication of superhydrophobic wood surfaces via a solution-immersion process

Superhydrophobic wood surfaces were fabricated from potassium methyl siliconate (PMS) through a convenient solution-immersion method. The reaction involves a hydrogen bond assembly and a polycondensation process. The silanol was formed by reacting PMS aqueous solution with CO2, which was assembled on the wood surface via hydrogen bonds with the wood surface –OH groups. The polymethylsilsesquioxane coating was obtained through the polycondensation reaction of the hydroxyl between wood and silanol. The morphology of products were characterized using a scanning electron microscope (SEM), the surface chemical composition was determined using energy dispersive X-ray analysis (EDXA), Fourier transform infrared spectroscopy (FT-IR), thermogravimetry (TGA) and contact angle measurement. Analytical results revealed that rough protuberances uniformly covered the wood surface, thus transforming the wood surface from hydrophilic to superhydrophobic. The water contact angle of the superhydrophobic wood surface was about 153° and a sliding angle was 4.6°.

Fabrication of Superhydrophobic Cellulose-Based Materials through a Solution-Immersion Process

An industrial waterproof reagent [(potassium methyl siliconate) (PMS)] was used for fabricating a superhydrophobic surface on a cellulose-based material (cotton fabric or paper) through a solution-immersion method. This method involves a hydrogen bond assembly and a polycondensation process. The silanol, which was formed by a reaction of PMS aqueous solution with CO 2, was assembled on the cellulose molecule surface via hydrogen bond interactions. The polymethylsilsesquioxane coatings were prepared by a polycondensation reaction of the hydroxyl between cellulose and silanol. The superhydrophobic cellulose materials were characterized by FTIR spectroscopy, thermogravimetry, and surface analysis (XPS, FESEM, AFM, and contact angle measurements). Analytical characterization revealed that nanoscale roughness protuberances uniformly covered the surface, thus transforming the cellulose from superhydrophilic to superhydrophobic with a water contact angle of 157 degrees . The superhydrophobic coatings were satisfactory with regard to both chemical and mechanical durability, and because of the transparency of the coatings the native cotton fabric displayed no changes with regard to either morphology or color. The easy availability of the materials and simplicity of this method render it convenient for mass production.