Fuente: Polymers Polymers, Vol. 18, Pages 1311: Durability of Silicone-Based Waterproofing Membranes in Hempcrete Systems Under Environmental Exposure: Role of Leachate Chemistry and Fiber Treatment
Polymers doi: 10.3390/polym18111311
Authors:
Elnaz Esmizadeh
Amir Sabziparvar
Marzieh Riahinezhad
Peter Collins
Esrat Jahan
Itzel Lopez-Carreon
Donato Tale Ponga

This study investigates the durability of silicone-based membranes in contact with hempcrete under combined moisture and temperature exposure. Membrane specimens were aged in contact with non-treated and treated hempcrete under dry and wet conditions at temperatures up to 90 °C. The evolution of chemical, thermal, and microstructural properties was characterized using FTIR, TGA, DSC, optical microscopy, and SEM–EDS analyses. Results show that dry exposure does not induce measurable changes in membrane structure or performance, confirming that temperature alone is not a critical degradation factor. In contrast, wet exposure leads to significant chemical, thermal, and microstructural changes in the membrane, including degradation of the siloxane network, reduced polymer chain mobility, and the formation of calcium-rich mineral deposits at the interface. These results indicate that membrane degradation is governed by a coupled moisture–ion mechanism involving ion transport, mineral deposition, and hydrolysis of the polymer network. Fiber treatment slightly reduces the aggressiveness of the leachate but does not prevent degradation under wet conditions. Overall, moisture availability and leachate chemistry are identified as key factors controlling the durability of silicone membranes in contact with bio-based materials.