| Abstrakt: |
Background: Silicone adhesives are prevalent in automotive and aerospace industries due to their extreme adhesion, resilience, durability, and toughness. However, they are still susceptible to damage induced by exposure to moisture and heat. Objective: Here, we performed a comprehensive analysis of the effect of water-induced damage on the mechanical performance of silicon-based adhesives, particularly their constitutive and failure properties. Methods: Distilled water and seawater were used as prevailing liquid media. After curing adhesives, dumbbell-shaped specimens were cut, immersed in liquid media, and aged at different temperatures and durations. Next, the constitutive and failure behavior of specimens were characterized in view of the aging profile. Furthermore, chemical characterization tests were performed to understand matrix evolution against the aging profile. We performed gravimetric measurements, FT-IR (Fourier-Transform Infrared) Spectroscopy, DMA (Dynamic Mechanical Analysis), SEM (Scanning Electron Microscopy), and cross-link density analysis. Results: We report the evolution of the aging matrix against time and temperature using a large set of experimental data points that cover the experimental rubric. Our results indicate that loss of mechanical performance in aging is directly correlated with water uptake. Moreover, aging in distilled water increases water uptake, while in seawater, the water uptake sharply decreases due to the formation of the sea salt cover layer. Conclusion: Water uptake is directly correlated with damage, and thus, it decreases strength and toughness. This phenomenon is indicated by the continuous increase in plasticization and reduction of Tg. [ABSTRACT FROM AUTHOR] |
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