Doctoral Defence: Ingrid Reban "Structure-property relationships of moldable silicone foams"

On 20 november at 13:15, Ingrid Rebane will defend her thesis "Structure-property relationships of moldable silicone foams".

Supervisor: 
professor Tarmo Tamm, University of Tartu

Opponent:
professor Anne Ladegaard Skov, Technical University of Denmark

Conclusion:
Elastomeric silicone foams are increasingly being used in cushioning applications. Their elastic and water-repellent properties, along with inherent fire retardancy and biocompatibility, give them a significant advantage over currently used synthetic foams. The incorporation of fillers and additives is a standard practice for enhancing mechanical resilience in applications involving constant dynamic compression. However, the multi-component nature of these composite blends poses challenges in achieving structurally homogeneous cellular foams, particularly in the low-density range, which is an essential characteristic, especially for the transportation industry. This thesis explores a specific foam synthesis technique involving two simultaneous catalytic processes in precursor blends: crosslinking and blowing. These reactions utilize hydride-functional polysiloxane, which becomes an integral part of the polymeric matrix and contributes to the blowing process through gas evolution. The studies conducted in this thesis analyzed gas evolution kinetics with monoalcohols and foam synthesis using water-alcohol blends as chemical blowing agents with varying compositions. This thesis proposes that the application of water-alcohol blends can improve the density of foams without compromising their mechanical properties. Furthermore, silicone foams with antibacterial additives were used to study their interaction with bacteria, specifically Escherichia coli. The results indicate that the antibacterial activity is hindered by the elastomer layer covering the antibacterial particulate additives. The antibacterial effect detected in this study originates from the leakage of antibacterial agents from the polymer matrix. The findings of these studies advance our understanding of how to tune foam structures and their interactions with microorganisms, which can enhance both the mechanical properties and sustainability of these foams.

Defence can be followed in Zoom: https://ut-ee.zoom.us/j/9530588152?pwd=ZzgzMjY4YytzUkZ5aVRCd2pOdVNQQT09  (meeting ID: 953 058 8152, passcode: kaitsmine).