Table 2.
Physical properties of synthesized PCUs as different types of alcohol and isocyanate chains 1.
| Entry | Alcohol (R1) | Isocyanate (R2) | Tg 2 (°C) | Tg 3 (°C) | Td5% 4 (°C) | Tdmax 5 (°C) | tan δ | E′ 6 (MPa) | Tv 7 (°C) |
|---|---|---|---|---|---|---|---|---|---|
| PCU-1H | FCD-1 | HDI (H) | 38 | 12 | 210 | 490 | 0.35 | 4.2 | 104 |
| PCU 1M | FCD-1 | HMDI (M) | 68 | 67 | 222 | 490 | 0.70 | 2.4 | 72 |
| PCU-3H | FCD-3 | HDI (H) | 46 | 14 | 190 | 490 | 0.52 | 122 | 118 |
| PCU-3M | FCD-3 | HMDI (M) | 60 | 69 | 220 | 490 | 0.60 | 0.54 | 65 |
1 Conditions: alcohol (FCD-1 or FCD-3, 1.0 eq), erythritol (1.0 eq), isocyanate (HDI or HMDI, 3.0 eq), DBTDL (1.0 mol%) using ball-milling 20 Hz for 60 min. 2 Defined as the temperature of the maximum in tan δ. 3 Determined by DSC for the first cooling range from 185 °C to −30 °C at a heating rate of 5 °C∙min−1. 4 Determined by the 5% weight-loss temperature from TGA. 5 Determined by the maximum temperature for fully degradation from TGA. 6 Determined by the rubbery plateau region in DMA curves. 7 Calculated using the Maxwell model and Arrhenius equation.