Effect of nano-flame retardants on oxygen index of plastic-wood composites
Test material
Wood shavings are mainly Yunnan pine and eucalyptus, the initial moisture content of 5.8%. High density polyethylene (HDPE) granules with a density of 0.941g/cm3~0.960g/cm3. Industrial grade silane coupling agent. Decomposition temperature 350¡æ. Nano-alumina hydroxide (nano-ATH), 50-60nm in the short axis direction and 300-400nm in the long axis direction. Analyze pure non-nano-alumina hydroxide (non-nano-ATH).
Equipment
Oxygen index tester, plastic-wood composite material preparation.
The ratio of plastic-wood composite is 6:4, and the dosage of silane coupling agent is 2%. The plastic, shavings, coupling agent building flame retardant according to the ratio of the side of the blender fully mixed, hand paved into 305mmx350mm loose slab. Prepress at room temperature (prepress pressure is IMPa, prepress is 30s), and then put the eight plate vulcanization machine for hot pressing. The nominal density of the plastic composite was set at 0.89/cm3, and the nominal thickness was 10xma. Main hot pressing parameters; Hot pressing temperature 180¡æ. Hot pressing time 12rain, hot pressing pressure 2MPa.
Performance test
The oxygen index of the wood-plastic composite was tested according to GB/T2406-1993, and the mechanical properties of the wood-plastic composite were tested with reference to the "Test method for physical and chemical properties of wood-based panels and veneer wood-based panels GB/T17657.1999".
Effect of flame retardants on WPc oxygen index.
Figure 1 uses 5 kinds of flame retardants, of which l represents nano MH, ¢ò represents nano ATH, ¢ó represents non-nano ATH, IV represents nano ATH+ nano MH(ratio 1:1), V represents nano ATn+ non-nano ATH(ratio 1:1), and the amount of flame retardants is 12%.
Figure 1 Oxygen index of the composite material with different flame retardants.
Figure 1 shows that the flame retardant performance of nano flame retardants is better than that of non-nano flame retardants; Nano-mh and ATH are used alone, and nano-ATH is slightly better than nano-MH; Nano-mh and nano-ATH mixed use, can produce synergistic effect; Nano-ath and non-nano-ATH mixed use, produce anti-synergistic effect. This is because the nanoparticles have small particles and large specific surface area, plus the size effect and surface effect of the nanoparticles themselves. The contact area between the flame retardant and the matrix is increased, the interaction and affinity of the interface between the flame retardant and the matrix are enhanced, and the compatibility of the two is improved; MH and ATH absorb the heat of 1.42MJ/kg, 1.2 MJ/kg, and MH thermal decomposition temperature is high, theoretically should be nano MH flame retardant effect is better than nano ATH, and this experiment appeared nano ATH slightly better than nano MH, this is because the two are not the same company products, although are nano, But there is still a difference in size, which affects its flame retardant effect.