Optimization and Characterization of Epoxidized Palm Oil‐Based Epoxy Polymers: Structure–Property Relationships for Sustainable Material Applications

ABSTRACT This study develops a tunable bio‐based epoxy platform by converting commercially available palm oil into an epoxy‐functional renewable modifier and systematically linking processing parameters to final material performance. The epoxidation of palm oil is optimized using response surface methodology (RSM) by varying temperature (45°C–65°C) and reaction time (2–6 h), and the optimum conditions are identified as 64.56°C and 5.91 h in a PID‐controlled reactor. Under these conditions, a maximum epoxidation efficiency of 80.98% is achieved with excellent model reliability ( R 2 = 0.9918, adjusted R 2 = 0.9886, C.V. = 0.4575%). The resulting modified palm oil (MPO) is incorporated into a commercial epoxy resin at 0wt%, 15wt%, 30wt%, and 45wt% and cured to form sustainable epoxy networks. Characterization demonstrates that increasing MPO content progressively decreases bulk density (±4 to 6 kg/m 3 ), Shore D hardness (±2 to 3), tensile strength (±1 to 2 MPa), thermal conductivity (±0.002 to 0.004 W/m K), and dielectric constant (±0.02 to 0.04), while significantly increasing elongation at break (±0.8% to 1.5%). These trends indicate a controlled transition from rigid to ductile behavior due to dilution of the aromatic epoxy network by flexible aliphatic chains and a corresponding reduction in crosslink density. FTIR spectroscopy confirms successful epoxidation through the loss of C=C bands and the appearance of epoxy C–O–C vibrations, whereas SEM reveals homogeneous morphologies at low MPO levels and phase separation at higher loadings. Curing kinetics slow with increasing MPO, reaching up to 48 h at 55°C compared with 24 h for neat epoxy. Overall, this optimized and scalable route enables the design of eco‐sustainable epoxy materials with tailored mechanical, thermal, and electrical insulation properties suitable for coatings, adhesives, and lightweight insulation applications.