DETERMINATION OF COHESION PARAMETERS FOR TERPENOIDS SUCH AS 1,8-CINEOLE USING SEMIEMPIRICAL METHODS AND CALCULATIONS BASED ON GROUP CONTRIBUTIONS

Methods of estimation of cohesion parameters for terpenoids have been reviewed, both semi-empirical and group contribution calculations, and with 1,8-cineole from eucalyptus oil as an example. The various calcu lated values have been compared with each other and with values determ ined from experimental measurements, in order to assess the relative r eliability of estimation methods. The information is required for the formulation of natural solvent blends to replace traditional hydrocarb on and chlorinated hydrocarbon solvents. A Hildebrand parameter of 17. 6 MPa(1,2) is the preferred value for 1,8-cineole.