Preparation And Application Of Zinc Stannate Coated Inorganic Nano-Particles As Flame Retardant

Tin compounds are known as non-toxic flame retardant and smoke suppressant agent for a wide range of organic polymers. Particularly in the polymer which contain organic chlorine bromine compounds have been show to exhibit good flame retardant. These effects are apparent even at low additive leves(1-5%). As strong surface effect and volume effect of nanoparticles, the polymer materials not only have better gas barrier, heat resistance but also have better mechanical properties when added nanoparticles. Zinc stannate coated on the surface of nano-inorganic flame retardant agents make it possible to improve the dispersion, reduce the cost, maintain the excellent flame retardant properties of zinc stannate and excellent mechanical properties of nanoparticles.In the first part of the study, zinc stannate was prepared from the precursors, which were synthesized by a homogeneous precipitation method. The calcined products of zinc stannate were characterized by XRD and TG/DTA. The results indicated that the optimistic condition of calcining was at 500℃for 3 hours.In the second part of the study,10% zinc hydroxystannate coated nm-CaCO3 was synthesized by a homogeneous precipitation method with ultrasonic and azeotropic technology. The flame retardant and smoke suppressant properties of zinc hydroxystannate coated nm-CaCO3 were studied compared with zinc hydroxystannate and nm-CaCO3. The mechanical property was also studied. The results showed that:the PVC treated with zinc hydroxystannate coated nm-CaCO3 has a lower SDR, and a similar tensile property and greatly improved impact strength compared the PVC without flame retardant.In the third part of the study,10% zinc stannate coated nm-CaCO3 was synthesized and applied into the PVC. The flame retardant and smoke suppressant properties of zinc stannate coated nm-CaC03 were studied. And the mechanical property was also studied. The results showed that:the PVC treated with zinc stannate coated nm-CaCO3 has a higher limiting oxygen index and lower SDR and greatly improved impact strength.In the fourth part of the study, the flame retardant, smoke suppressant and mechanical properties of 10% zinc hydroxystannates coated nm-Mg(OH)2 were studied in PVC, and also studied in EVA. The results showed that by adding 20phr of zinc Stannate coated nm-Mg(OH)2 to PVC, the LOI of it rises to 43.8% and the smoke densityis reduced to 64.75% and greatly improved impact strength compared with the PVC without flame retardant. Also EVA treated with zinc stannate coated nm-Mg(OH)2 have high LOI and greatly improved mechanical property.