Effect of Magnesium Borates on the Fire-Retarding Properties of Zinc Borates

Abstract

Magnesium borate (MB) is a technical ceramic exhibiting high heat resistance, corrosion resistance, great mechanical strength, great insulation properties, lightweightness, high strength, and a high coefficient of elasticity. Zinc borate (ZB) can be used as a multifunctional synergistic additive in addition to flame retardant additives in polymers. In this study, the raw materials of zinc oxide (ZnO), magnesium oxide (MgO), and boric acid (H 3 BO 3 ) were used in the mole ratio of 1 : 1 : 9, which was obtained from preexperiments. Using the starting materials, hydrothermal synthesis was applied, and characterisation of the products was performed using X-Ray diffraction (XRD) and Fourier transform infrared (FT-IR) and Raman spectroscopies. The forms of Zn 3 B 6 O 12 ⋅3.5H 2 O, MgO(B 2 O 3 ) 3 ⋅7(H 2 O), and Mg 2 (B 6 O 7 (OH) 6 ) 2 ⋅9(H 2 O) were synthesised successfully. Moreover, the surface morphology was investigated using scanning electron microscopy (SEM), and the B 2 O 3 content was determined. In addition, the reaction yields were calculated. The results of the B 2 O 3 content analysis were in compliance with the literature values. Examination of the SEM images indicated that the obtained nanoscale minerals had a reaction efficiency ranging between 63-74% for MB and 87-98% for ZB. Finally, the fire-retarding properties of the synthesised pure MBs, pure ZBs, and mixtures of MB and ZB were determined using differential thermal analysis and thermal gravimetry (DTA-TG) and differential scanning calorimetry (DSC).

A Novel Synthesis of Zinc Borates from a Zinc Oxide Precursor via Ultrasonic Irradiation

“…22 ZnO was defined as the key reactant. The synthesis reaction was repeated three times for each condition, and the results were averaged to obtain the yield and standard deviation.…”

“…Ultrasonic irradiation produced a uniform particle size distribution with particle sizes between 130 nm and 506 nm, in contrast to hydrothermal synthesis. 22 The sub-micron particle size was observed because of the agglomeration effects of Van der Walls forces between the nanoscale zinc borates 1 . A thorn-like particle morphology was observed for specia) b) Fig.…”

“…As a result, high productivity can be achieved even at low reaction temperatures and shorter reaction times. 15,16 In the literature, several studies can be found on the use of sonochemistry for the preparation of different materials, such as ZnO, 17 22 However, sonochemistry has not been applied for the synthesis of zinc borates. Our group has published two studies on the production of zinc borates via the ultrasonic route.…”

Visualizing the Microdistribution of Zinc Borate in Oriented Strand Board Using X-Ray Microcomputed Tomography and SEM-EDX

“…Nevertheless, zinc borate particles could be clearly seen at higher magnifications in voids or in lumens of some cells within wood strands (Figures 2(b) and 2(c), arrowed). These particles were knobbly and irregular in shape and resembled the type 1 form of particles found in zinc borate powder and photographed by Gnatowski [27], rather than the rhomboids or irregular aggregates of spheres, platelets, and shards, which are also described in [27][28][29]. There was great variation in the size of zinc borate particles in OSB; for example, particles larger and smaller than 20 m and 1 m, respectively, were common.…”

Synergistic Flame Retardant Effect of Organic Phosphorus–Nitrogen and Inorganic Boron Flame Retardant on Polyethylene

“…ZB mainly plays a condensed phase flame retardant mechanism . ZB decomposes to form zinc oxide and boron oxide . Boron oxide is softened by heat at high temperatures to form a boron‐containing coating, which suppress the release of flammable volatiles and prevent heat exchange .…”