The polymerisation of BH-A is confirmed by the disappearance of key benzoxazine monomer bands at 1230 and 934 cm -1 in the FTIR spectrum of polyBH-A (Figure ). The ring- The result of thermogravimetric analysis of polyBH-A is illustrated in Figure . A 5% weight loss temperature of 293°C is recorded, indicating a greater thermal stability compared to a similar polybenzoxazine vitrimer which has a value of 252°C . PolyBH-A features a high char residue of 57.4% at 850°C which, according to Eq.1, corresponds to an 𝐿𝑂𝐼 of 40.5%.