IMPACT OF HEXAMETHYLDISILAZANE ON BEETROOT POWDER BYPRODUCTS AND POLYMER INTERACTION: PROPERTIES AND INTERFACIAL DYNAMICS

Polydimethylsiloxanes (PMDSs) are most used polymer in siloxane elastomer. However, because of an intrinsic weak connection between PDMS chains, these polymers exhibit poor mechanical strength and tear resistance, which limits their application. To enhance their properties many fillers including pigments from fruit and vegetable waste, have been studied as a sustainable reinforcement. Because of their low price, accessibility, and environmental benefits, natural reinforcements have become more and more popular in recent years, spurred by environmental concerns. The aim of this study is to incorporate the coarse powdered beetroot waste (BWP) before and after silylation into PDMS and to investigate the effect of silylating agent on the properties of composites. In this study BWP was incorporated into single component poly(dimethylsiloxane) (PDMS) macromolecular matrix at different concentrations (5%, 10%, 15%, and 20%) before and after silylation with hexamethyldisilazane (HMDS) by a mixing process to develop a bioelastomer composites with tuneable properties. Hexamethyldisilazane (HMDS) is a silylating agent was used to modify the fillers and to investigate its effect for hydrophobicity, thermal stability, and reinforcement effects. The color of beetroot powder changed from red to dark brownish after silylation, indicating chemical modifications. The results showed that hydrophobicization improved the surface wettability by up to 20%. This implies that the material’s surface became more hydrophobic. From SEM analysis the obtained composite with the beetroot powder shows strong adhesion at the interface (the area where different materials meet). This suggests that the pigment might play a role in improving the interaction between the composite material and any surface it adheres to, possibly enhancing the mechanical properties. Tensile strength in PDMS/beetrootHMDS 20% inceraese 35 % compare with pure PDMS. In addition to improving the interfacial adhesion between the filler and silicone composites, silylation promotes the network’s densification of materials. Keywords: Silylation, hexamethyldisilazane (HMDS), polydimethylsiloxane (PDMS), bioelastomer composites, natural fillers, sustainable materials.