Study on Aeronautical Sealants after Artificial Accelerated Aging

Artificial accelerated aging behaviors of the polysulfide sealants(XM-22B、XM-23) and the fluorosilicone sealant(FVMQ) were studied.Artificial accelerated aging experiments of XM-22B and FVMQ samples were carried out by means of hot-air,and XM-23 samples were carried out by means of xenon arc lamp.Then the appearances of the samples were analyzed,and their tensile strengths were measured.Finally,the change of radicals of the sealants was analyzed by FT-IR.The results show that the gloss of sealants little changed before and after aging.The tensile strength of aeronautical sealants was less obvious after aged for 28 days.The tensile strength of XM-22B increased by 2% after being aged by hot-air aging,FVMQ increased by 5% after being aged by hot-air aging,and the tensile strength of XM-23 decreased by 3% after being aged by xenon lamp aging.Whether it is hot-air aging or xenon lamp aging,Shore A hardness of aeronautical sealants was increased.Shore A hardness of XM-22B,XM-23 and FVMQ increased by 15%,23% and 11% respectively.It is concluded that XM-23 has no clear degradation after being aged for 28 days.