CHARACTERIZATION OF RUBBER-SOLVENT INTERA CTION BY INVERSE GAS-CHROMATOGRAPHY

The interaction between various structured hydrocarbons and nonpolar t ypes of rubber (EPDM, NR, 1,2-BR, cis-BR and SBR) was studied by Inver se Gas-Chromatography (IGC) in a temperature range of process-technolo gical relevance. The information contained in the specific retention v olumes led to a quantitative characterization of the systems. The solv ent quality of the alkanes improved in each of the rubbers studied as the number of C atoms increased. Because of their high contribution to mixing entropy cyclic hydrocarbons have the best solvent properties. Aromatic structures in EPDM make only a small additional contribution to the mixing free energy. The thermodynamic solvent quality experienc es a steady improvement as the delta parameter of the rubbers rises. I n the temperature range studied, the higher the number of C atoms, the better the interaction between alkanes and covalent types of rubber.