Abstract: A method for continuously preparing a formulated polyamide prepolymer, of which the solution viscosity is from 0.25 dL/g to 0.70 dL/g, as measured according to ISO 307:2007 in m-cresol at 20° C., the method including a step of polycondensation on the basis of one or more polyamide precursor monomers, said polycondensation step being carried out in an extruder comprising at least two co-rotating conveying screws, the at least one monomer being previously fed therein in solid or liquid form without being dissolved in a solvent or in water, and said polycondensation step being carried out without extraction of the water formed during said polycondensation step and comprising the addition of at least one additive during said polycondensation step in the extruder.

Abstract: The present invention relates to a process for preparing a powder composition based on polyamide(s) with an optimized yield. The process includes a step of recycling a composition based on a polyamide prepolymer having a lower Dv50, by polycondensation of a mixture comprising said composition and one or more monomers in the presence of water. The invention also relates to the powder composition obtained and to the use thereof, especially for coating metal substrates by fluidized bed dip-coating.