Brittleness, plasticiser loss

Heat ageing can reduce the life of a sealant or adhesive, which is generally due to the loss of plasticiser from the material. Elevated temperatures may also increase the amount of crosslinking (post-cure hardening) and oxidisation, both of which may reduce the moveability of die sealant and induce brittle fracture in adhesive joints. In order to understand the effects of heat ageing, thermal testing should he carried out. 

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