Investigation of mechanical and thermo‐mechanical properties of dopamine‐functionalized <scp> TiO ₂ </scp> /epoxy nanocomposites

Abstract In the last decades, tremendous research has been performed to enhance the thermo‐mechanical properties of polymer composites with lightweight, high strength, and low density with respect to conventional materials. The present investigation deals with an approach towards the enhancement of thermo‐mechanical properties of nanocomposite by incorporating bio‐inspired dopamine functionalized titanium dioxide (TiO 2 ) nanofiller. Material characterization has been performed via XRD, SEM, FT‐IR, and TGA to confirm the synthesis of TiO 2 and ensure proper surface functionalization over TiO 2 nanopowder. The epoxy nanocomposite was fabricated by blending varying weight percentages (0–2%) of surface functionalized DTiO 2 nanoparticles, using a dual mixing probe ultrasonication technique to achieve uniform dispersion. The most significant enhancements in mechanical properties, counting tensile strength, flexural strength, and work of fracture (WOF), showed an optimum increase of 29%, 24%, and 63%, respectively, notably at a 1 wt% concentration of DTiO 2 60 particles as compared to the base composite. Additionally, the tensile and flexural moduli enhanced by 26% and 30%, respectively, at 2 wt% TiO 2 . Examination of fracture surfaces using FESEM indicated that the surface‐modified DTiO 2 nanofillers were uniform and dispersed within the epoxy matrix, highlighting improved interfacial adhesion. The incorporation of 1 wt% TiO 2 resulted in a substantial increase in storage modulus of 179%, along with improvements in glass transition temperature (110°C) and damping factor (0.6), while maintaining other thermal properties. To expand industrial usability, eco‐friendly nanofillers need to meet established standards, confirming the fabrication of robust epoxy nanocomposite systems suitable for structural composite manufacturing. Highlights Surface functionalization of TiO 2 with dopamine has been done by the sol–gel method. An avg. particle size of DTiO 2 powder is approximately 120 nm with a rough surface after functionalization. DTiO 2 ‐infused epoxy nanocomposites were prepared, and their thermo‐mechanical properties were examined. Tensile strength and storage modulus were improved by ~29% and ~179%, respectively. FESEM fracture surface analysis showed improved mechanical interlocking between the filler and matrix, leading to shearing –yielding.