Lewis Acid-Base Properties of Cellulose Acetate Phthalate-Polycaprolactonediol Blend by Inverse Gas Chromatography

摘要

The net retention volumes, V_N, of n-alkanes and five polar probes are determined on cellulose acetate phthalate-polycaprolactonediol blend column by inverse gas chromatography in the temperature range 323.15-363.15 K. The dispersive surface energy, γ_s~d, of the blend has been calculated using the V_N values of n-alkanes and the γ_S~d at 333.15 K is 12.6 mJ/m2. The γ_S~d values are decreasing linearly with increase of temperature. The V_N values of the five polar solutes are used to calculate the specific component of the enthalpy of adsorption, ΔH_a~S. The Lewis acid-base parameters, K_a and K_b, are derived using ΔH_a~S values and are found to be 0.019 and 0.403, respectively. The K_d and K_b values indicate that the blend surface contain more basic sites and interact strongly with the acidic probes. The acid-base parameters have been used to analyze the preferential interaction of the solid surface with acidic and basic probes.