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 h to 168 h after sample creation. These cure times fall between the proposed RILEM TC139 technical recommendation of 5 min and the ASTM C719 standard of 21 d. Apparently, enough cross-linking occurred prior to 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.
Citation: Polymer Degradation and Stability
Pub Type: Journals
ASTM C719, cross-linking, cure, mechanical properties, polymer, rubber elastisity, sealant