Branched polyamide with different blocks

Process for the preparation of a high molecular weight branched polyamide polymer, comprising

• (1) a melt-mixing step wherein
• an essentially linear polyamide (pre)polymer (X-1), predominantly consisting of AA-BB repeat units,
• an essentially linear polyamide (pre)polymer (X-2), predominantly consisting of AB repeat units, and
• a branching agent, are provided to and mixed and heated in a melt mixing apparatus, thereby forming a mixed melt, and the mixed melt being cooled, thereby forming a solid mixture;
• and
• (2) a solid state post condensation step wherein the solid mixture is post-condensed at elevated temperature in the solid state, thereby forming a high molecular weight branched polyamide polymer.
• wherein
• the (pre)polymers (X-1) and (X-2) are provided in a weight ratio (X-1)/(X-2) in the range of 0.25-4;
• the (pre)polymer (X-1) and/or the (pre)polymer (X-2) have a viscosity number (VN), measured according to ISO 307, in the range of 50-250 m L/g;
• the branching agent is a branched polyamide oligomer/prepolymer (Y) comprising a branching unit derivable from a monomer (referred to as monomer C) having at least three functional groups being either amino groups and/or carboxylic acid functional groups or precursor groups thereof, and optionally AA-BB and/or AB repeat units;
• the branching unit is present in an amount in the range of 0.05-1 mole %, relative to the total molar amount of AA repeat units, BB repeat units, AB repeat units and branching units;
• the high molecular weight branched polyamide polymer obtained after the solid state post condensation has a relative viscosity (RV) measured according to ISO 307 of at least 2.5.