Characterization of polyisoprene by temperature gradient interaction chromatography

Abstract

Temperature gradient interaction chromatography (TGIC) analysis of polyisoprene (PI) is reported. PI can be fractionated in terms of molecular weight with high resolution by TGIC using a C18 bonded silica column as the stationary phase and a mixture of CH2Cl2/CH3CN (80/20, v/v) as the mobile phase. The temperature was increased during the elution from 5 degrees C to 34 degrees C to optimize the fractionation of high molecular weight PI. The relatively poor resolution in the low molecular weight range was improved by changing the eluent composition. For example, all the oligomeric species from the unimer to the 29mer of a low molecular weight PI (average mol. wt.: -900) were fully resolved with the mixed eluent of CH2Cl2/CH3CN (50/50, v/v) and a linear temperature program from 5 degrees C to 40 degrees C. In addition, simultaneous size exclusion chromatography and TGIC fractionation of PI/polystyrene, PI/poly(methylmethacrylate) mixtures are also reported.