A method for removing impurities from ethylene copolymers and -pfropfmischpolymerisaten

A method for removing impurities from ethylene copolymers and -pfropfmischpolymerisaten (ethylene polymers) containing copolymerized carboxyl groups, residues of at least one α, β-ethylenically unsaturated carboxylic acid and / or at least one α, β-ethylenically unsaturated comonomer, in a vented extruder by melting the ethylene polymers one in the melting zone of the extruder and or multi-stage degassing of the resultant Ethylenpolymerisatschmelze in the degassing zone, characterized in that a devolatilization is the ethylene polymer before the completion of degassing at least one place of the extruder is added, whereby it is compounds in the Entgasungshilfsmitteln which are able, the volatility of the still present in the ethylene copolymers or -pfropfmischpolymerisaten (ethylene polymers) impurities by chemical reactions and / or by forming a Azeot to increase rops with these impurities.