Research Progress on Flame-Retardant of Silicone Rubber

The development of the flame-retardant of silicone rubber and flame-retardant mechanism of polymer has been reviewed. The studies on assorted flame retardant systems used in silicone rubber matrix are reviewed too. The influence of halogenated flame retardants, metal hydroxide, transition metal compounds, as well as flame retardant with nanoparticle on flame resistance properties of polymer are discussed in detail. Owing to the negative effects on the environment, Directive 2002/95/EC of the European Parliament on the Restriction of Hazardous Substances (RoHS) had restricted the use of certain brominated flame retardants in electrical and electronic equipment. The aluminum trihydroxide and magnesium dihydroxide are both the resultful and popular metal hydroxide flame retardants, because of its less cost, halogen-free, safety use, produces nontoxic fume, and et al. The transition metals of Platinum, rhodium, iridium and their compounds could improved flame resistance of silicone rubber, the platinum compound is the best and particularly effective among them, which acts as both a catalyst and a flame retardant and usually used with other flame retardant, such as metal hydroxide. The flame retardants contained nanofillers have many advantages, such as efficiency, functionality, reduced fuming, friendly environment and low loading, which promote its application in the filled polymer. The most promising nanofillers including clay layered silicates, carbon nanotubes and polyhedral oligomeric silsesquioxanes (POSS) have caught many researcher's eye, and the study on improving the flame resistance of polymer had been focused. It can be expected that the above nanofiller and platinum compound may have a prosperous future in promoting the fire resistance of transparency required polymer.