Physical property changes in commercial structural silicone sealants due to weathering
MetadataAfficher la notice complète
The changes in physical properties of three different commercial silicone sealants used in structural glazing applications were monitored as a function of various environmental and climatic aging factors. These variables included, exposure to solar radiation(UV) and simulated rainfall in which the pH of the water ranged from 3 to 11. The extremes of the pH range represent recorded values for acid rain(pH=3) and basic cleaning solutions(pH=11), respectively. A second portion of the study involved contacting test coupons simultaneously with simulated rain and high levels of gaseous ozone. The experimental tensile tests coupons were cut from sheets of DC-790, DC-995 and DC-983. An Instron tester was used to measure the changes in engineering properties such as moduli and tensile strengths of the test samples as a function of time of exposure to the different variables. Unexposed samples, kept at ambient laboratory conditions, were used as the control.