Fluorosilicones are less stable than conventional methyl silicones because they are more likely to revert to low molecular weight cyclic products

especially in sealed circumstance.As for RTV fluorosilicone rubbers

they are usually vulcanized by ethyl silicate and diethylene diamine

and liable to suffer from reversion by water and catalyst and alcohol byproducts emit during vulcanization.Instead of ethyl silicate

one RTV fluorosilicone rubber was prepaired by using polysilazane KH-CL as crosslinking agent without using diethlene diamine as catalyst. The thermal stability of fluoroislicone rubber crosslinked by KH-CL(FSi-B) was compared with fluorosilicone rubber crosslinked by ethyl silicate and diethylene diamine (FSi-A)in sealed circumstance by TG、IGA and solubility. The results showed that FSi-B was such more stable than FSi-A due to eliminating water and siloxy that can lead to reversion of fluorosilicone rubber.