| Silicone rubber (SR) is one of the important special synthetic rubbers, withexcellent performance. And it is widely used in the fields of wire and cable, electricaland electronics, aerospace, automotive in recent years. However, the flammablecharacteristics of SR when it is ignited restrict its application in some fields. Thus, it isnecessary to develop flame retardant silicone rubber composites. Nowadays,halogenated flame retardants, with a high flame retardant efficiency, have already beenwidely used in the world. However, halogen flame retardant produces large amounts ofhydrogen halides when burning. It’s difficulty for people to escape and rescue in caseof fire. And the smoke can also harm the environment and human health. As people’sawareness of environmental protection, the development of non-toxic, non-halogen,environmental friendly flame retardants adapt to trend and the prospects is quite broad.In this paper, the halogen-free intumescent flame retardant (IFR), expandable graphite(EG), alumina trihydrate (ATH), and synergistic agents were used to prepare flameretardant SR composites by mixing method. And, the flammability, thermal stabilityand smoke suppression properties of SR composites were studied using severalmethods, including cone calorimeter test and smoke density test, et al. the main contentincludes the following in this paper.(1) Smoke suppression effects of Fe2O3in intumescent flame retardant siliconerubber composites. IFR (based on phosphorus acid, melamine, and pentaerythritol),mixed with Fe2O3, prepared the SR/IFR/Fe2O3composites. The results from smokedensity test (SDT) and cone calorimeter test (CCT) revealed that Fe2O3could increaseflame retardant and smoke suppression effectively. Meanwhile, TG showed that Fe2O3can improve the thermal stability of the composites materials(2) Synergistic effects of FeOOH in intumescent flame retardant silicone rubbercomposites combustion characteristics and thermal degradation kinetics. Silicone rubber mixed with FeOOH and IFR to prepare the flame retardant silicone rubbercomposites. CCT test results showed that adding FeOOH, can significantly improvedflame retardant and smoke suppression characteristics. TG showed that the FeOOHcan improve activation energy of material, and thus enhance the thermal stability of thesilicone rubber material.(3) The synergistic effects of zinc oxide (ZnO) with IFR in silicone rubber (SR)composites and thermal degradation kinetics. The results showed that ZnO couldimprove the LOI, greatly reduce the peak of heat release rate (HRR), mass loss, totalheat release and smoke production rate (SPR). The kinetics parameters wereinvestigated using Kissinger, Flynn-Wall-Ozawa (FWO), Friedman-Reich-Levi (FRL),and Kissinger-Akahira-Sunose (KAS) methods and studied the flame retardantmechanism.(4) Flame retardant effects of organic inorganic hybrid intumescent flameretardant based on expandable graphite in silicone rubber composites. The organicinorganic hybrid intumescent flame retardant (FEG) synthesized based on EG, POCl3and PER. IR and CCT results showed that PER successfully grafted to EG. FEG caneffectively reduce the flammable properties, smoke generation and improve thethermal stability of the material, enhanced fire safety performance of the material.(5) The synergistic flame retardant effects between red phosphorus (RP) andalumina trihydrate (ATH) in silicone rubber (SR) composites. The synergistic effectsbetween RP and ATH were studied using limiting oxygen index, UL-94, CCT,thermogravimetric analysis, and digital photographs. RP has a synergistic effect withATH in the flame retardant SR composite system. RP could promote the formation ofthe homogenous and compact char layer. And containing1.0wt%RP in SR showedthe best flame retardant properties. |
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