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

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

• a) providing components comprising a grafted elastomer, one or more dianhydrides, and one or more diamines;
• wherein the grafted elastomer is provided at a content of at least 60 wt. % based on the total weight of the components;
• and wherein the elastomer of the grafted elastomer is selected from natural rubber, epoxidized natural rubber, styrene-butadiene rubber, nitrile rubber, chloroprene rubber, ethylene propylene rubber, ethylene-propylene-diene monomer (EPDM) elastomer, butyl rubber, chlorobutyl rubber, acryl rubber, silicone rubber, fluorine-containing rubber, butadiene rubber, epoxidized butadiene rubber, epichlorohydrin rubber), urethane rubber, polysulfide rubber, ethylene-octene copolymer;
• thermoplastic elastomers;
• b) performing in situ synthesis of a polyimide phase in the grafted elastomer 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 an elastomer-polyimide blend;
• and
• c) recovering said elastomer-polyimide blend being a reinforced elastomeric material wherein the polyimide of the elastomer-polyimide blend is present at a content from 3 to 40 wt. % based on the total weight of the reinforced elastomeric material.