The Effects of Corn Kernel Bio-Filler on the Fire Retardancy of Intumescent Fire-Retardant Coating for Steel Structures

The development of bio-based intumescent coatings is a focal point for achieving sustainability and eco-friendly coatings. This study introduces Corn Kernel (CK) bio-filler into a modified epoxy-based fire-retardant system, resulting in significant improvements in thermal resistance. This study develops intumescent coatings, utilizing CKs, and assesses the samples through thermal performance testing, char expansion analysis, and char morphology examination. The incorporation of 8% CK (CKC-8) enhanced the thermal performance of the coating, with a backside temperature recorded at 190.28 °C during the ASTM E119 test. Furthermore, the char expansion of the coating increased by 22.14%. The Thermogravimetric Analysis (TGA) examined the thermal pyrolysis behavior, revealing a 3% increase in residual mass. The Fourier Transform Infrared Spectroscopy (FTIR) and X-ray Diffraction (XRD) analyses confirmed the effective degradation of the CK, leading to the formation of CaCO3 in the char. The Field Emission Scanning Electron Microscope (FESEM) images demonstrated the presence of cross-linked char structures within the CK-filled char samples.