Abstract:In order to study the influence of short-term aging temperature on the properties of sealant,a sealant was prepared,and field construction conditions were simulated.The properties of the sealant before and after short-term aging at 180?220 ℃ were tested.The viscoelastic properties,physicochemical properties,and microstructures of the sealant were studied,and the mechanism of property changes was discussed.The results show that the cone penetration and flow value of the aged sealant decrease,while the softening point and elastic recovery rate increase.Aging at high temperature (>180 ℃) for a short time and low temperature (160 ℃) for a long time will cause obvious property changes.The tensile properties under low temperatures do not decrease monotonically as the temperature increases.The results of the physicochemical property test and microstructure characterization show that the polar groups of the aged sealant at higher temperatures increase significantly,and the glass-transition temperature of the components increases.The storage modulus increases,while the sealant prepared at a higher temperature has a lower viscosity,which makes it much easier to penetrate into the pores at the bonding surface to form mechanical anchorage.Meanwhile,the increase in polarity due to aging generates a higher chemical interaction force with the bonding surface,thus improving the bonding performance.With ongoing aging,the viscosity of the sealant increases,and the bonding performance decreases.Therefore,the comprehensive properties of the sealant do not linearly decrease with the increase in short-term aging temperature but are affected by the viscoelasticity and bonding performance.