Table 5.
Differential scanning calorimetry (DSC) results and viscosity of urethane prepolymers.
| Sample (UPX-CE-Y) * | DSC results | Viscosity | ||
|---|---|---|---|---|
| Tg1 of 1st heating | Tm of 1st heating | Melting enthalpy | ||
| UP1-O-0 | −48.58 | -- | -- | 3640 |
| UP2-O-0 | −50.01 | -- | -- | 3640 |
| UP1-DI-0.34 | −45.98 | -- | -- | 6500 |
| UP2-DI-0.34 | −46.27 | -- | -- | 6060 |
| UP1-DI-0.54 | −44.68 | -- | -- | 6150 |
| UP2-DI-0.54 | −43.67 | -- | -- | 7740 |
| UP1-DI-0.74 | −43.82 | -- | -- | 8600 |
| UP2-DI-0.74 | −42.93 | -- | -- | 11,080 |
| UP1-DI-0.94 | −39.63 | -- | -- | 22,400 |
| UP2-DI-0.94 | −39.05 | -- | -- | 12,000 |
| UP1-PEN-0.34 | −48.15 | -- | -- | 6920 |
| UP2-PEN-0.34 | −47.43 | -- | -- | 5100 |
| UP1-PEN-0.54 | −44.83 | -- | -- | 9220 |
| UP2-PEN-0.54 | −44.54 | -- | -- | 6820 |
| UP1-PEN-0.74 | −43.10 | 59.98 | 2.176 | 17,500 |
| UP2-PEN-0.74 | −45.41 | 53.25 | 1.688 | 45,600 |
| UP1-PEN-0.94 | −43.82 | 58.28 | 2.138 | 50,880 |
| UP2-PEN-0.94 | −42.52 | 56.52 | 2.304 | 52,600 |
| UP1-TRI-0.74 | −38.91 | -- | -- | 9950 |
| UP2-TRI-0.74 | −40.35 | -- | -- | 9600 |
| UP1-BUT-0.74 | −43.10 | 83.58 | 3.016 | 36,200 |
| UP2-BUT-0.74 | −43.53 | 81.41 | 3.229 | 44,000 |
* X: synthesis processes: 1—one-shot process, 2—two-stage process; CE: chain extender: DI—di-PPG, TRI—tri-PPG, PEN—pentanediol, BUT—butanediol; Y: the molar ratio of chain extender to PPG 2000.