Preparation Of Halogen-Free Flame-Retardant Silicone Rubber Composites

In many fields, silicone rubber is called for flame retardant property, but in fact it is flammable, so it is necessary to be modified.In this thesis, the flame retardant properties, mechanical properties and microscopic structure of silicone rubber (Q)/conventional flame retardants composites were studied. The results show that flame-retardant synergistic effect between hydrated compounds and metallic oxides. The composites containing magnesium hydroxide (Mg(OH)2) alone show better flame retardant effect than aluminium hydroxide (Al(OH)3), but the compatibility between Mg(OH)2 and silicone rubber is worse than Al(OH)3. The composites containing iron trioxide (Fe2O3) or aluminium (Al2O3) alone cann't be classified in vertical burning test. Flame-retardant synergistic effect between Al(OH)3 and Fe2O3 is better than Al(OH)3 and Mg(OH)2. The composites containing 100 quotas Al(OH)3 and 50 quotas Fe2O3 reach FV-0 degree in vertical burning test.Furtherly, the flame-retardant effect and droplet material inhibiting ability of OMMTs, which have been modified by intercalators cetyl trimethyl ammonium bromide (CTAB) and tributyl phosphate respectively, were studied. The results show that the composites containing OMMT alone can both inhibbit droplet material, decrease smoke and dust, but aren't flame-retardant. The results also show that the composites containing 100 quotas Al(OH)3,40 quotas Fe2O3 and 3 quotas OMMT-1 or 5 quotas OMMT2 can reach FV-0 degree in vertical burning test. Thermal gravimetric analysises (TGA) show that, thermal stability of OMMTs is better than MMT's, and OMMT-1's is better than OMMT-2's.Thirdly, the results show that lanthanon oxide cann't inhibbit droplet material, decrease smoke and dust, not to mention it is flame-retardant. Lanthanon oxide can enhance thermal stability by comparing blank test (the composites containing small amount of packing material, not any flame retardant) and composites containing small amount of lanthanon oxide. The composites containing lanthanon oxide, Al(OH)3 and Fe2O3 show flame-retardant synergistic effect. The composites combining 100 quotas Al(OH)3,40 quotas Fe2O3 and 0.8 quotas lanthanon oxide can reach FV-0 degree in vertical burning test.