Organic reinforcement of a polyamide with the in situ synthesis of a polyimide phase by reactive extrusion

A process to produce a reinforced polyamide characterized in that it comprises:

• a) providing components being one or more polyamides, one or more dianhydrides, and one or more diamines;
• wherein the one or more polyamides are provided at a content ranging from 60 to 97 wt. % based on the total weight of the components and wherein the one or more polyamides comprise at least one polyamide having amide groups separated by at least 10 CH2 groups;
• b) performing in situ synthesis of a polyimide by reactive extrusion of the components in a twin-screw extruder comprising a main hopper wherein the screw profile comprises two or more reverse conveying elements forming two or more hot zones to form a polyamide-polyimide blend wherein the residence time is less than 10 minutes, wherein the residence time is determined according to the method of the description;
• and
• c) recovering a polyamide-polyimide blend being a reinforced polyamide comprising a continuous polyamide phase and a dispersed polyimide phase.