Investigation of thermal properties and structural characterization of novel boron-containing Schiff base polymers

Three novel Schiff base polymers were synthesized by using the Schiff base monomer obtained using aldehyde containing boric acid and amines containing hydroxyl groups as the starting materials. The polymers were synthesized at the same temperature and using the same amount of oxidizing agent by the oxidative polycondensation method. The characterization of all polymers and monomers was achieved by using Fourier transform infrared spectroscopy (FT-IR), ultraviolet–visible spectroscopy (UV–vis), nuclear magnetic resonance spectroscopy (¹H-NMR), liquid chromatography-mass spectrometry (LC–MS), gel permeation chromatography (GPC) and scanning electron microscopy (SEM). The thermal stability of these compounds was studied by employing thermogravimetric analysis (TGA), and thermodynamics parameters such as activation energy (E_a), enthalpy (∆H), entropy (∆S), and Gibbs free energy(∆G) for the decomposition process were calculated using the Flynn–Wall–Ozawa method.