Solid State Sciences, vol.165, 2025 (SCI-Expanded)
Epoxy resins (E) are widely used in composite applications due to their superior properties such as lightweight, manufacturing flexibility, and compatibility with numerous reinforcement elements. To enhance these properties and mitigate drawbacks like low toughness, curing agents that improve chain linkages and nanofillers are employed. Nano-sized zinc borates (ZB), commercially available materials, are frequently studied for improving the thermal stability, mechanical strength, and fire resistance of polymeric structures. ZB, with the formula 2ZnO·3B2O3·3.5H2O, is a white crystalline nanomaterial that possesses low toxicity, anti-corrosive properties, low density, and compatibility with various polymers. Although many studies focus on improving the thermal stability and mechanical properties of ZB-epoxy composites (ZB-E), research on curing processes remains limited. However, selecting parameters like temperature and curing duration under system transformations is crucial for composite production. Curing kinetic parameters are essential for accurately analyzing these processes. This study evaluates the curing process of epoxy systems containing different mass fractions of ZB (2-4-6-8-10 %) through dynamic differential scanning calorimetry (DSC) tests. DSC analyses were conducted at various heating rates (3-6-9 °C/min) with a final curing temperature of 120 °C. The obtained data were analyzed using different phenomenological kinetic equation models (Kissinger, Flynn-Wall-Ozawa, Boswell, and Moynihan) in Matlab-R2019b, and the curing kinetic parameters were calculated. At the same time, the reaction order was calculated using the Crane method. In the final stage, Arrhenius equations were applied to determine the activation energies of the systems. This study assesses the influence of ZB addition on epoxy curing kinetics and the activation energies of ZB-E structures. The activation energy (Ea) values calculated from different models (Kissinger, FWO, Moynihan, and Boswell) show some variation, but the overall trend is consistent: as the ZB content increases, the activation energy generally decreases. The Ea value calculated using the Kissinger, FWO, Moynihan, and Boswell methods decreases by approximately 35.48 %, 33.27 %, 33.27 %, and 34.63 % respectively, when the ZB content increases from 0 % to 10 %. It also provides a new perspective for pre-production optimization and characterization of composite curing systems, aiming to reduce manufacturing costs and production times.