1. Preparation

The polycondensation reaction is a balanced reaction between the end groups —NH ₂ (amine) and —COOH (acid) leading to the formation of —CONH— (amide) groups and water.

The polymer obtained at the end of the reaction, possibly in the presence of a chain limiter, therefore still contains a certain amount of water, residual monomer(s) and oligomers.

Careful drying is necessary before subsequent use, otherwise there is a risk of equilibrium displacement with a reduction in molecular weight.