FMagnesium hydroxide-based flame-retardant fillers for polymer materials and the effect of particle size on the dehydration process at high temperatures

Abstract

Exemplifed by various grades of magnesium hydroxide used as halogen-free flame-retardant fillers, the regularities of the destruction and dehydration process depending on the size of the disperse phase particles – from large (45 microns) to nanoparticles (50–100 nm) – were considered for the first time.By DTA and TGA methods, the effect of the size of magnesium hydroxide particles on the temperature of the beginning of decomposition, the temperature range of the dehydration reaction, the kinetics and volumes of water release, the thermal effects of the reaction and the formation of coke residue when exposed to high temperatures was established.The analysis of the data obtained allows us to draw the main conclusion - the particle size of halogen-free fire-retardant fillers has a significant effect on the parameters and kinetics of the process of decomposition of magnesium hydroxide (the brucite mineral) at high temperatures, which must be taken into account when creating and processing dispersed-filled polymer composite materials (DFPCM).It has been established that from the point of view of the decomposition process and the release of water by flame retardants at high temperatures, grades based on magnesium hydroxide with a particle diameter of more than ~10 μm are the most effective for the production of DFPCMs.