Papers by Keyword: Magnesium Hydroxide

Abstract: Polyether sulfone (PES) stands as a widely utilized polymeric membrane in separation technology. However, due to certain undesirable drawbacks encountered in its application, researchers consistently strive to enhance its characteristics and performance. In this study, we delve into the effects of Mg(OH)₂ addition on the characteristics and performance of PES membranes employed for humic acid removal from water. The membrane fabrication involves PES as the primary polymer, NMP as the solvent, and a blend of ethanol and water as non-solvents. Characterization of the membranes encompasses the assessment of functional groups via FTIR, morphological structure through SEM imaging, and porosity evaluation. Notably, the Mg(OH)₂ additive exerted a positive influence on the prepared PES membranes, leading to discernible alterations in the morphological structure, as evident in SEM cross-sectional images. The augmentation of Mg(OH)₂ concentration resulted in increased membrane porosity. The FTIR spectra revealed the presence of water derived from Mg(OH)₂ crystals. The research yielded notable results, with the most outstanding membrane exhibiting a pure water flux of 41.6 L/m2·h and a rejection rate of 71%. Furthermore, it displayed a Water Flux Recovery Ratio (FRR) of 72%. These findings underscore the effectiveness of incorporating Mg(OH)₂ as an additive in enhancing the performance of PES membranes for humic acid removal, with promising implications for water purification applications.

Abstract: Low weight is one of the most important factors in the design process of road and flight vehicles. The design engineers are careful with regards to the weight decrease without thinking twice about the primary strength. The composite is a lightweight material that has decent underlying properties and it is generally utilized. Fiber-supported polymer composites assumed a prevailing part for quite a while in an assortment of uses for their high explicit strength. The current work portrays the turn of events and the portrayal of another arrangement of GFRP. Experiments are carried out to study the effect of the addition of fillers by varying their percentages. The present work focus on the effect of the fillers on properties of Glass fiber epoxy laminates with aluminum oxide and magnesium hydroxide powders as the fillers. In the present work, fabrication and experimental investigation on unidirectional glass epoxy composites are carried out. Initially, glass fiber reinforced polymer laminate fabricated without filler material, hand layup followed by vacuum bagging methods are used . Then, by adding Aluminium oxide and Magnesium hydroxide as a filler material with different percentages like 5%, 10%, and 15% by weights and laminates are fabricated and experimental investigation is conducted to study their mechanical behavior. The comparative studies on the laminates are carried out and the obtained results are analyzed and those are quite interesting.

Abstract: Nowadays, the fire behavior of polymer composite materials is a concern in automotive applications. Due to the flammability of this type of compounds, the present study focused on analyzing the influence of the flame retardants of aluminum hydroxide and magnesium hydroxide on the flammability index. A DOE was carried out using a complete factorial design using two categorical variables (type of resin and type of retardant at two levels) and one quantitative variable (volumetric percentage of the retarder for 3 levels). Twelve combinations of composite material were manually conformed maintaining the general volumetric fraction (30% reinforcement, 70% polymer matrix). Percentages of retardants (3.6 and 9%) were part of the volumetric composition of the matrix. The performance and evaluation of the flammability test was carried out under ISO 3795: 1989 and FMVSS 302. In addition, the average temperature inside the test chamber was measured to observe its behavior during combustion. The results showed that the flammability index was significantly reduced with the use of polyester resin with retarder aluminum hydroxide at any percentage and the highest temperature inside the chamber was produced by the combustion of the epoxy resin with 9% retardant of flame.

Abstract: The objective of this paper is to introduce a patented and eco-friendly method to synthesize aqueous suspension of all types of alkaline-earth metal hydroxides nanoparticles (NPs). This method is based on an ion exchange process; the exchange takes place at ambient temperature/pressure, starts from cheap or renewable reagents and, in one single step, results in the creation of the crystalline desired nanoparticles in only a few minutes. In terms of structural and morphological features, the synthesized nanoparticles are characterized by means of XRD-Rietveld refinement, FTIR, and TEM. In particular, we obtained pure and crystalline magnesium and calcium hydroxide suspensions, showing the typical brucite crystal structure with a hexagonal lamellar morphology and dimensions generally <100 nm. With respect to the strontium and barium hydroxide suspensions, we observed different kinds of hydroxides (either anhydrous and hydrate forms), characterized by orthorhombic or monoclinic crystal lattices with rod-like nanostructured morphologies. Despite the different morphologies, all synthesized nanoparticles appear constituted by a superimposition of primary nanoparticles, of dimensions ranging from a few to 15 nm, correlated to the increase in the atomic number of the alkaline earth metal.

Abstract: This work aimed to use magnesium hydroxide (MH) as a flame retardant in poly(lactic acid) (PLA)/high impact polystyrene (HIPS)/wood flour (WF) composite. The 80/20/20 PLA/HIPS/WF composite was melt mixed with three loadings (20, 30 and 40 phr) of MH on a twin screw extruder, followed by an injection molding. The prepared wood-plastic composites (WPCs) were investigated for their impact strength (IS), tensile strength (TS), Young’s modulus (E), elongation at break (EB), flammability and morphology. The results showed that the 80/20/20 PLA/HIPS/WF composite exhibited higher IS, TS and E than the neat PLA, but at the expense of reducing the EB. It was also found that the WPCs filled with MH at all loadings provided much higher flame resistance and E over the neat PLA, HIPS, PLA/HIPS blend and PLA/HIPS/WF composite. Therefore, the MH could play an effective role as flame retardant in the WPCs.

Abstract: The magnesium hydroxide whiskers,its length being about 30μm and its diameter being about 3μm, was prepared by hydrothermal conditions. The effect of preparation technology, which includes the reaction temperature and reaction time, was discussed according to the results of XRD, TEM, and SEM. Moreover, the mechanism of the preparation of magnesium hydroxide whiskers was studied.

Abstract: Hydrothermal synthesis as a new coating technique has been developed to produce biomedical coating in Mg alloys in recent years. This paper summarized the process feature and corrosion resistance of hydrothermal synthesis coating in Mg alloys, and then reviewed the synthesis process, microstructure, corrosion behavior and corrosion mechanism of the Mg (OH)₂ biomedical coatings. Finally, the current problems and research prospect of this technique in biomedical Mg alloys were discussed.

Abstract: The magnesium hydroxide (Mg(OH)₂, MH) was modified using oleic acid (C₁₇H₃₃COOH, OA) by wet techonlogy. The modification effect of MH was evaluated by activation index and oil absorption rate. The optimum technological conditions were as follows: the concentration of magnesium hydroxide slurry was 35wt%, the oleic acid 2wt% ,temperature 70 °C, time 40 min and a stirring rate 2200 rpm. Additionally, the structure and morphology of the improved modified MH powders were characterized by SEM, XRD, FTIR, TGA-DSC. Compared with the unmodified MH, the modified MH had better dispersibility and hydrophobicity.

Abstract: Produced in industrial production processes such as electrolysis, electroplate and metal pickling, industrial wastewater, which contains acids, varieties of heavy metal and whose pH value is less than 6, can be very damaging to our daily life and environment and is an urgent issue to be solved. In recent years, with environmental protection becoming an important issue around the world, and environmental regulations becoming more and more complete, the traditional water treatment technology which can cause secondary pollution is gradually restricted, and this leads to the result that environmental scientists and engineers pay more attention on the development and application of "environmentally friendly" water treatment technology ^[1]. Of all acid wastewater neutralizers, magnesium hydroxide, known as "green and safe neutralizer" ^{[2, 3]}, is safe, reliable, non-toxic, harmless, and has high buffer performance, high activity, high adsorption capacity, and no corrosivity compared with traditional strong alkali substances (such as CaO, Ca (OH) ₂ and NaOH, etc.). Therefore magnesium hydroxide has been widely used in the acid wastewater neutralization ^[4].

Abstract: For achieving sufficient flame retardancy, high magnesim hydroxide (MH) content is needed in MH flame retardant Acrylonitrile-butadiene-styrene copolymer (ABS) composites (ABS/MH), which will cause a great decrease in mechanical property and difficulty in preparing samples for measurement. We prepared ABS/MH filled high 60.0% flame retardant by compounding ABS and modified flame retardant MH, fumed silica (SiO₂) and zinc borate (ZB) via TX-10 phosphate/polyacrylate latex and studied the effect of a small amount of SiO₂ and ZB with MH in ABS for improving the thermal decomposition of ABS/MH. The thermal stability of the modified flame retardant could meet the processing temperature of ABS. The incorporation of ZB, SiO₂ or SiO₂/ZB could improve the thermal stability of ABS/MH.