From Fossil to Bio-Based AESO-TiO₂ Microcomposite for Engineering Applications

Environmental issues and the reduction of fossil fuel resources will lead to the partial or total substitution of petroleum-based materials with natural, raw, renewable ones. One expanding domain is the obtaining of engineering materials from vegetable oils for sustainable, eco-friendly polymers for different applications. Herein, the authors propose a simplified and green synthesis pathway for a thermally curable, acrylated and epoxidized soybean oil matrix formulation containing only epoxidized soybean oil, acrylic acid, a reactive diluent (5%) and just 0.15 mL of catalyst. The small amount of reactive diluent significantly reduced the initial system viscosity while eliminating the need for adding solvent, hardener, activator, etc. Both the thermally cured composite with a 2% TiO₂ microparticle filler and its pristine matrix were comparably characterized in terms of structural, thermal, morphological, dielectric and wettability by Fourier transform infrared spectroscopy, differential scanning calorimetry, thermogravimetry, scanning electron microscopy, broadband dielectric spectrometry and contact angle measurements. The 2% filler in the composite generated superior thermal stability via lower mass loss (48.89% vs. 57.14%) and higher degradation temperatures (395 °C vs. 387 °C), increased the glass transition temperature from -20 °C to -10 °C, rendered the microcomposite hydrophobic by increasing the contact angle from 88° to 96° and enhanced dielectric properties compared to the pristine matrix. All investigations recommend the microcomposite for protective coatings, capacitors, sensors and electronic circuits. This study brings new contributions to green chemistry and sustainable materials.