EXPERIMENTAL AND NUMERICAL STUDIES OF HEAT TRANSFER THROUGH BIO-DRIVEN POLYMER FOR FIRE RETARDANT

Abstract

This study presents a combined experimental and numerical investigation of heat transfer in bio-derived intumescent coatings (ICs) with the aim of enhancing fire protection for steel structures in industrial settings, particularly in the oil and gas sector. The research focuses on Reduced Super Intumescent (RSI) coatings formulated with sustainable ingredients such as ammonium polyphosphate (APP) and tannic acid (TA), offering an eco-friendly alternative to conventional flame retardants. Experimental methods, including thermogravimetric analysis (TGA), scanning electron microscopy (SEM), and methane torch fire testing, were used to assess coating performance under fire conditions. Porosity evolution and thermal conductivity were analyzed using MATLAB-based image processing and guarded heat flow meter measurements. Complementing the experimental work, a finite element heat transfer model was developed in COMSOL Multiphysics to simulate the transient temperature profile through the coating and steel substrate, incorporating porosity-dependent thermal conductivity. The simulation outcomes demonstrated strong agreement with experimental results, confirming the significant role of porosity in reducing heat transfer and improving fire resistance. Key findings indicate that increased porosity correlates with decreased thermal conductivity—from 0.15 W/m·K to 0.05 W/m·K—attributed to the formation of an expanded char layer during thermal decomposition. This research bridges existing gaps in the understanding of thermophysical behavior in ICs by integrating physical testing with digital modeling tools, a framework validated for optimizing next-generation fire-retardant coatings. The work provides new insight into the fireproofing potential of bio-derived ICs for passive fire protection systems in high-risk industrial applications.