Adipic acid, 6 mols, was condensed with 14 mixtures of glycols, preferably with 1:2:2:1 or 0:3:2:1 (by moles) 2-Bu2-Et-1,3-propanediol/2-Me-1,3-propanediol/ethylene glycol/neopentyl glycol, at 200-210degreesC, to prepare dicarboxylic polyesters. As the acid no. (L) was similar to50 mg KOH/g, the terminal groups were blocked with 2.5 mols 2-ethylhexanol (catalyst added) at 200-210degreesC. At L = 10, the mixture was distilled in vacuo to collect the plasticizer of a volatility =0.7% (180degreesC, 30 min, thermobalance). Crude plasticizer, L = 3, was neutralized with NaOH, filtered with active C at 80degreesC, and used in (100:65:4 by wt) PVC-plasticizer-dibasic Pb phthatate mixtures to roll out (13/16 rpm, 7 min, 170/175degreesC) 1-mm films from which 200x200 x 1-mm plates and other test profiles were prepared. Volatility, d. and h of the plasticizers, and thermal and mechanical properties of the PVC films were determined. Plasticization effectiveness and volatility of plasticized PVC were hardly related to glycol mixture composition and polyester volatility, resp. When used in tyre filling compounds, the present plasticizers imparted a favorable frost, transverse dielectric, and chemical (to gasoline and oils) resistance, as compared with a well-known imported plasticizer. The higher the proportion of branched glycols in the plasticizer, the better the PVC. Two plasticizers prepared similarly from phthalic anhydride were ineffective.