Table 2. Thermal Properties of C-(VT-OPE) and C-(OPE-2St).
| sample code | Tg (°C) (DMA)a | E′ at Tg +40 °C (MPa) | cross-linking density (mmole/cm3)b | Tg (°C) (TMA)c | CTE (ppm/°C)d |
|---|---|---|---|---|---|
| C-(VT-OPE)e | 242 | 22 | 1.59 | 202 | 55 |
| C-(OPE-2St)e | 229 | 19 | 1.41 | 199 | 76 |
a
Measured by DMA at a heating rate of 5 °C/min. Defined by the peak temperature of the tan δ curve.
b
The cross-linking density accords with E′/3RT, in which E′ is the storage modulus in the rubbery plateau (E′ at Tg +40 °C).
c
Measured by TMA at a heating rate of 5 °C/min. Defined by the onset temperature of TMA thermograms.
d
Coefficient of thermal expansion, defined at 50 to 150 °C by TMA thermograms.
e
Mn of VT-OPE is 4069 g/mol, and Mn of OPE-2St is 4336 g/mol (NMP as the eluting solvent) the respective results are depicted in Figure S6a,b.