The present invention concerns polymer blends and processes for the preparation thereof. The present blends contain a) 5 to 95 parts by weight of poly(2,6-dimethyl-1,4-phenylene)ether, b) 95 to 5 parts by weight of a second polymer which is immiscible therewith, and c) a component (a compatibilizer) which enhances the compatibility of the polymers. According to the invention the component enhancing the compatibility of the polymers comprises 0.1 to 10 %, preferably about 1.5 to 10 %, calculated on basis of the total weight of components a and b, of at least one compound C, which has the formula (I): Ai-Bj wherein A stands for a group which contains at least one ring with 3 to 7 members, capable of forming ring-to-ring interactions with the phenyl rings of poly(2,6-dimethyl-1,4-phenylene)ether; B is a polar group; i is an integer 1 to 20; and j is an integer 0 to 20; whereat i + j is greater than or equal to 2; the melting point of compound C is above 50 °C and the boiling point thereof above 200 °C (at 760 mmHg) and c; compound C is capable of at least partially dissolving poly(2,6-dimethyl-1,4-phenylene)ether. The polymer blends according to the invention are processible and their elasticity moduli are at least 10 % greater than those of blends which do not contain substance C, which has instead been replaced by the same amount of component b. The polymer blends can be used for the preparation of fibres, coatings and films.