Table 1.
Molar mass (M), glass transition temperature (Tg) calculated from DSC and BDS experiments, ambient-pressure fragility index (mp), activation energy for secondary relaxation (Ea), energy barrier for rotation of the changeable substituent (Eg) and pressure coefficient of glass transition temperature (dTg/dp) for compounds 1 and 2.
| Parameter | Compound 1 | Compound 2 |
|---|---|---|
| M (g∙mol−1) | 398 | 444 |
| Tg from DSC (K) | ~263 | ~304 |
| Tg from BDS (K) | 262 ± 1 | 302 ± 1 |
| mp | 82 ± 2 | 83 ± 2 |
| Ea (kJ∙mol−1) | 23 ± 1 | 23 ± 1 |
| Eg (kJ∙mol−1) | 25 | 20 |
| dTg/dp (K∙GPa−1) | 230 ± 2 | 246 ± 2 |