Inverse gas chromatography of poly(cyclohexyl methacrylate)

Inverse gas chromatography is applied to determine the glass transition temperature Tg of poly‐(cyclohexyl methacrylate). Both good and bad solvents for the polymer are used as molecular probes. Although the transition is clearly detected by both types of probes, only the nonsolvents yield a Tg in quantitative agreement with the value determined by differential scanning calorimetry. The relative depth of penetration of the probe in the polymer phase is calculated from retention volume data. Also, the height equivalent to a theoretical plate is calculated from peak halfwidths. Both calculated magnitudes show a temperature dependence which significantly differs from good to bad solvents. Some kind of diffusion‐limited penetration of the probe in the bulk of the glassy polymer may be responsible for the difference.