Assessment of the Effect of Phosphorus in the Structure of Epoxy Resin Synthesized from Natural Phenol–Eugenol on Thermal Resistance

This work aimed to investigate the thermal properties of phosphorus-modified epoxy resin obtained from eugenol derivatives and cured with different amines: aliphatic-triethylenetetramine (TETA); aromatic-diaminodiphenylmethane (DDM); and cycloaliphatic-isophoronediamine (IDA). The thermal stability was investigated through both thermogravimetric analysis (TGA) coupled to a Fourier transform infrared spectrometer (TGA/FTIR) and pyrolysis-combustion flow calorimetry (PCFC). The structures of the cured castings and the char residues were assessed by scanning electron microscopy (SEM). Eugenol-based resin during thermal degradation is covered with a significant amount of char residue and is characterized by a reduced value of heat release rate (HRR) and heat release capacity (HRC) compared with the resin based on petrochemicals.