Inverse gas chromatography (IGC) is a new characterizing method for surface properties in polymer field.The main difference between GC and IGC is that the interested species is the polymer material acting as the stationary phase in IGC column.Probe solvents with known properties are injected in column.For the interactions between probe solvents and polymer stationary phase are different

the surface properties of polymer can be determined from the retention volume of probe solvents.In this work

surface properties of soluble polyimide HQDPA-DMMDA were quantitatively analyzed by the IGC method.Four n-alkanes (C6

C7

C8 and C9) were chosen as non-polar probes to characterize the dispersive component of free energy.Trichloromethane (CHCl3)

ethyl ether and acetone were chosen as polar probes to detect the Lewis acid-base parameters.It was found the dispersive component of free energy of HQDPA-DMMDA was 34.37 mJ/m2

31.80 mJ/m2

29.50 mJ/m2 and 27.64 mJ/m2 at 50℃

60℃

70℃ and 80℃

respectively.The surface free energy decreased linearly with increasing temperature.The Lewis acidic number Ka of HQDPA-DMMDA was 0.4115

and basic number Kb was 0.5812.The result meant that HQDPA-DMMDA was a weak Lewis amphoteric polymer.