Process for the production of a polybenzoxazine monomer

A process for manufacturing a polybenzoxazine monomer comprising condensing an amine of formula A with a polyaldehyde of formula B in order to obtain the polybenzoxazine monomer of formula C, formulas A, B and C being provided below:

• in these formulas:
• R1a is a substituted or unsubstituted furfuryl group or a substituted or unsubstituted benzyl group,
• R2a is selected from:
• electron-withdrawing groups;
• saturated or unsaturated, substituted or unsubstituted, linear or branched hydrocarbon chains comprising between 1 and 6 carbon atoms, interrupted or not interrupted by one or more heteroatoms;
• saturated, unsaturated or aromatic, substituted or unsubstituted carbocyclic or heterocyclic groups;
• na is an integer comprised between 0 and 2;
• B1 is selected from:
• monocyclic or polycyclic, substituted or unsubstituted aromatic carbocyclic or aromatic heterocyclic groups;
• and
• N1 is an integer greater than or equal to 2.