The Effect of Ultrafine Magnesium Hydroxide on the Tensile Properties and Flame Retardancy of Wood Plastic Composites

Abstract

The effect of ultrafine magnesium hydroxide (UMH) and ordinary magnesium hydroxide (OMH) on the tensile properties and flame retardancy of wood plastic composites (WPC) were investigated by tensile test, oxygen index tester, cone calorimeter test, and thermogravimetric analysis. The results showed that ultrafine magnesium hydroxide possesses strengthening and toughening effect of WPC. Scanning electron micrograph (SEM) of fracture section of samples provided the positive evidence that the tensile properties of UMH/WPC are superior to that of WPC and OMH/WPC. The limited oxygen index (LOI) and cone calorimeter test illustrated that ultrafine magnesium hydroxide has stronger flame retardancy and smoke suppression effect of WPC compared to that of ordinary magnesium hydroxide. The results of thermogravimetric analysis implied that ultrafine magnesium hydroxide can improve the char structure which plays an important role in reducing the degradation speed of the inner matrix during combustion process and increases the char residue at high temperature.

Graphene-Borate as an Efficient Fire Retardant for Cellulosic Materials with Multiple and Synergetic Modes of Action

“…The harmful consequences of using BFRs and CFRs eventually have led these products to be banned in 2010 following the “San Antonio Statement” . These BFRs and CFRs have been identified as mutagenic, carcinogenic, and extremely toxic, demanding for their urgent replacement with eco-friendly alternatives. , To address these problems, several nonhalogen based fire-retardants have been developed using inorganic metal hydrates (aluminum hydroxide, magnesium hydroxide, zinc borate, and borax), − expandable graphite, , phosphorus, ,, nitrogen, , and silicon-based compounds, , and other nanocomposites. ,, …”

“…The hydrated-SMB being nontoxic, low cost, having a high thermal stability and ability with controlled release of water molecules is recognized to be a good candidate as a fire-retardant material. SMB and other metal hydrates can also act as a chemical heat sink during combustion as they undergo endothermic decomposition that can cause ignition delay. − In addition, the incorporation of other properties is also essential for better protection such as char formation, alteration of thermal properties, dilution of flammable gases, and inhibition of chemical reactions to resist combustion …”

Synthesis, mechanical, and flammability properties of metal hydroxide reinforced polymer composites: A review

“…[119] In the effect of ultrafine magnesium hydroxide (UMH) and ordinary magnesium hydroxide (OMH) investigation of the tensile properties and flame retardancy of wood-plastic composites (WPC). [126] The tensile properties (tensile strength and elongation at break) of WPC improved when 30% ultrafine magnesium hydroxide was added to pure WPC system, while the opposite effect occurred when 30% of ordinary magnesium hydroxide was added to pure WPC system. This was attributed to the fact that the compatibility of UMH and WPC was better than that of OMH and WPC owing to their smaller size and good dispersion.…”

“…The results indicated that the ductility and tensile strength of the HDPE composites became weaker due to the incorporation of magnesium hydroxide particles into the polymer. In an attempt to mitigate the shortfall of high MgOH 2 loading few studies focused on using ultrafine MgOH 2 particles [77,126] and another on nano-MgOH 2 particles. [119] In the effect of ultrafine magnesium hydroxide (UMH) and ordinary magnesium hydroxide (OMH) investigation of the tensile properties and flame retardancy of wood-plastic composites (WPC).…”

“…Various studies are available in literature in which they suggested investigation on several inorganic materials to be applied as filler [77,78,[108][109][110][111][112][113][114][115][116][117][118][119][120][121][122] in a polymer and in some used both fibers and inorganic fillers combined. [123][124][125][126][127] In reference to this, mechanical properties such as Young's modulus, tensile strength, impact strength, and flexural strength of polymer composites filled with unmodified and/or modified magnesium hydroxide are reviewed. Furthermore, a summary of mechanical properties investigated in the literature is shown in Table 6.…”