Studies on the effect of movement during the cure on the mechanical properties of a silicone building joint sealant

A novel sealant testing device was used to continuously monitor the mechanical properties of a one‐part silicone sealant for movement cycles initiated from 10 to 168 h after sample creation. These cure times fall between the proposed RILEM TC‐139 technical recommendation of 5 min and the ASTM C719 standard of 21 days. At 10 h of cure, enough crosslinking occurred before testing such that neither the overall movement history of the sample nor the deformation step shapes affected subsequent curing of the sealant. A critical parameter for sealant performance appears to be the extent of cure at the onset of movement. POLYM. ENG. SCI., 2010. © 2009 Society of Plastics Engineers