Bicyclooctane derivatives as plasticizers

The invention relates to the use of bicyclo[3.3.0]octane derivatives as plasticisers or solvents for polymers. including thermoplastics. The use of isosorbide esters, isosorbide polyesters, isosorbide ethers, isosorbide carbonates, isosorbide thioethers, isosorbide thioesters, isosorbide amides, isosorbide (thio)urethanes, isosorbide urea, isosorbide phosphates and isosorbide phosphonates as a plasticizer is described. Instead of isosorbide it is also possible for corresponding diols such as isomannide and similar compounds, in which the ring oxygen atoms of the isosorbide have been replaced by carbon or by other heteroatoms, to serve as a base. In particular, this relates to C-Calkanoates of isosorbide, isomannide and the like. In particular, the compounds are used as a plasticizer inpoly(vinylchloride), optionally in conjunction with usual plasticizers such as dioctyl phthalates.