Thermal analysis of the prepared lignin/graphene oxide/polyurethane composite

Lignin/graphene oxide/polyurethane composite was prepared for removing polyaromatics from wastewater. X-ray and TEM are used for the characterization of the prepared composite. Thermal analysis was carried out for two reasons. One reason to ascertain the composite formation and the second to study the thermal stability of the synthesized composite. The kinetic parameters for each one of the decomposition steps were calculated through four methods of the non-isothermal decomposition kinetics calculations, and the kinetic mechanisms were determined by analyzing the thermal data by using thirty-five solid-state reaction models. The results showed that the mechanisms of decomposition steps depend on the type of starting materials. It was observed as the thermal decomposition that lignin passes through an unjustified mechanism. Graphene oxide shows a two-dimension diffusion mechanism. However, the synthesized Lignin/Graphene oxide/Polyurethane composite exhibits a chemical reaction mechanism (one and a half order and second order. The thermodynamic parameters ΔS#, ΔH# and ΔG#, were also computed and discussed.