Process for the production of a dianhydrohexitol based polyester

Process for the production of a polyester by the polycondensation of a mixture comprising isoidide, and a dicarboxylic acid or dicarboxylic acid anhydride, wherein the reaction is performed in the melt of the monomers and wherein these monomers are not activated. The polyesters based on one or more of the three isomers of dianhydrohexitol, being isosorbide, isomannide and isoidide, have properties which makes them suitable to be used in powder coatings, toner compositions as well as engineering plastics. The polyesters include a polyester according to the following formula, wherein n ranges from 3 to 300