Influence of carbon black filler on pyrolysis kinetic behaviour and TG-FTIR-GC–MS analysis of glass fibre reinforced polymer composites

Highlights: • Pyrolysis behaviour of CB/GFRP was studied using TG-FTIR-GC–MS. • The elemental, proximate, and compositional analyses of CB/GFRP was measured. • Pyrolysis kinetics were studied using linear and nonlinear isoconversional methods. • TGA and DTG curves were simulated using DAEM and IPR models. • Phenol and p-Isopropenylphenol were the major compounds in GC-MS. Recently, several filler materials, such as carbon black (CB), have been added to glass fibre reinforced polymers (GFRP) to enhance their mechanical and electrical performance. So far, we have insufficient information on the effect of these additives on the recyclability of GFRP and the resulting products. Within this context, this is the first research developed to study the effect of these additives on pyrolysis behaviour of GFRP. The experiments were started with dispersion of CB in epoxy resin solution, then CB/GFRP panels were prepared using vacuum-assisted resin transfer technique, followed by grinding to prepare the feedstock. The ultimate, proximate, and morphological properties of the CB/GFRP samples were analysed. Afterwards, TG-FTIR-GC measurements were conducted on the milled samples at several heating rates. Depending on the TG analysis, the pyrolysis kinetics of CB/GFRP were studied using both linear and nonlinear isoconversional methods (i.e., Kissinger, KAS, FWO Friedman, Vyazovkin, and Cai). Also, TGA-DTG data was simulated using the distributed activation energy model and the independent parallel reactions kinetic model. The results show that the fibre is rich in volatile content (45%), while aromatic benzene and C–H bond were the major groups in the TG-FTIR analysis. In addition, phenol and p-Isopropenylphenol were the major compounds in the GC-Ms measurements with abundance of 67% (with improvement of 146% compared with neat GFRP) and 33%. Meanwhile, the pyrolysis kinetic showed that KAS, Vyazovkin, and Cai models are the most appropriate isoconversional methods that can be used to study of the pyrolysis kinetic of CB/GFRP with estimated activation energies in the ranges of 198–209 kJ/mol (with improvement of 64% compared with neat GFRP). Based on that, the filler materials added to GFRP composites, including CB filler, act as self-catalysts during the pyrolysis treatment leading to increased yield and better quality of the formulated volatile compounds.