Surface Modification of Super-Fine Magnesium Hydroxide Powder and it’s Flame-Retardant Treatment of Flexible PVC

Abstract

Surface modification is very important to industrial application of the magnesium hydroxide (MDH) powder, which is used as a kind of environment-friendly flame-retardant. In this paper, a kind of MDH powder surface-modified with silicane coupling agent and stearic acid is synthesized, and its potential usage in the flame-retardant treatment of flexible PVC is studied. The influence of the surface treatment to the dispersion of the powder in PVC, the flame-retardant and other physical properties of the MDH flame-retardant treated flexible PVC are discussed in detail. The surface modification mechanism of MDH is studied by the FTIR analysis, and then the surface modification model is established. Results show that molecules between the surface of the particle and these two modifiers form stable chemical bonds, and this kind of surface modification can improve the MDH’s dispersion and the compatibility of the flexible PVC. When the flame-retardant flexible PVC is produced according to the mass composition of PVC/DOP/MDH=100:50:80 and a few other additives, its oxygen index is 31.5, the elongation at break is 240%, the tensile strength is 13.0MPa, the hypothermia tendering is +30/-0, the volume resistivity at 20°C is 3.2×1011Ω•m. These index are just correspondent with requires of the halogen-free fire-retardant flexible PVC.

Synergistic effects of hydroxides and dimethyl methylphosphonate on rigid halogen‐free and flame‐retarding polyurethane foams

“…There is also growing interest in magnesium hydroxide for its relatively high decomposition temperature (300°C) and better match with many polymer systems than aluminum trihydrate fillers 18, 19. Magnesium hydroxide has been adopted as a flame retardant in many polymers19, 20 such as polypropylene,21–23 ethylene vinyl acetate,24–26 polyethylene,27, 28 polyamide,29 and poly(vinyl chloride) 30. Brucite, the mineral form of magnesium hydroxide with the chemical formula Mg(OH) 2 , can be used as a flame retardant.…”

The synergism of MgCO3 and 2ZnCO3·3ZnO·4H2O as flame retardants and smoke suppressants for flexible poly(vinyl chloride) (PVC)

“…Compound additives containing metals like antimony, zinc, copper, iron, aluminium, magnesium, and molybdenum are widely used in reducing flammability and in smoke suppression, in which the most important commercial smoke suppressants are zinc, magnesium and aluminum compounds, such as zinc borate (XZnO·YB 2 O 3 ·ZH 2 O), Al(OH) 3 , Mg(OH) 2 and MgCO 3 etc. are commonly used [1][2][3][4][5][6]. Although these fillers are essentially non-toxic and relatively inexpensive, the high volume of addition for excellent flame retardancy often leads to processing difficulties and a marked deterioration in other critical polymer characteristics, including mechanical, physical and electrical properties [7][8].…”