Transition temperatures of the investigated l,d-PLA, and composite layers under different conditions were detected by the DSC method.
| Environment | T g [°C] | ΔCp [J (g °C)−1] | T onset [°C] | T end [°C] | ΔH [J g−1] | X c [%] | ||
|---|---|---|---|---|---|---|---|---|
| l,d-PLA | Heating | H2O | 50.8 | 0.465 | 141.8 | 153.8 | 0.807 | 0.861 |
| HCl | 50.3 | 0.380 | 142.0 | 153.6 | 0.681 | 0.727 | ||
| NaOH (30 days) | 53.0 | 0.435 | 143.4 | 155.0 | 0.774 | 0.826 | ||
| Air | 48.9 | 0.440 | 141.5 | 152.8 | 0.701 | 0.748 | ||
| Cooling | H2O | 51.7 | 0.393 | — | — | — | — | |
| HCl | 51.3 | 0.519 | — | — | — | — | ||
| NaOH (30 days) | 53.3 | 0.378 | — | — | — | — | ||
| Air | 50.5 | 0.421 | — | — | — | — | ||
| Composite | Heating | H2O | 45.9 | 0.388 | 136.7 | 151.3 | 17.465 | 21.434 |
| HCl | 46.7 | 0.370 | 137.3 | 151.4 | 18.069 | 22.176 | ||
| NaOH | — | — | — | — | — | — | ||
| Air | 46.4 | 0.404 | 137.9 | 151.0 | 13.677 | 16.785 | ||
| Cooling | H2O | 45.7 | 0.378 | — | — | — | — | |
| HCl | 46.4 | 0.384 | — | — | — | — | ||
| NaOH | — | — | — | — | — | — | ||
| Air | 46.7 | 0.399 | — | — | — | — | ||