Process for the preparation of a polyamide

A process for preparing granulated particles of a semi-crystalline semi-aromatic copolyamide from diamines and a dicarboxylic acid, the process comprising the steps of:

• (i) forming a powder comprising a diamine/dicarboxylic acid salt (DD-salt) by dosing a liquid diamine mixture comprising at least two aliphatic diamines selected from C2-C10 diamines to an agitated powder comprising an aromatic dicarboxylic acid selected from the group consisting of terephthalic acid, 2,6-naphthalene dicarboxylic acid, biphenyl-4,4′-dicarboxylic acid and combinations thereof at a dosing rate of at most 4 mole % diamine per minute, relative to the molar amount of the dicarboxylic acid such that the dicarboxylic acid constitutes at least 50 mole %, relative to the total molar amount of dicarboxylic acid of the agitated powder, thereby forming the powder comprising the DD-salt in the absence of melting, and thereafter
• (ii) subjecting the powder comprising the DD-salt without intervening melting of the powder to solid-state polymerization conditions to thereby obtain the granulated particles of semi-crystalline semi-aromatic copolyamide having a microporous structure with a BET surface value of at least 0.4 m2/g as measured according to ISO 9377:2010 and a particle size distribution (d50) of at least 50 μm.