Table 2 Parameters of thermal denaturation of collagen in new vegetable tanned leathers and new parchment
Collagenous material | Tonset/°C | Tmax/°C | ∆H/J g−1 | ∆T1/2/°C | \(C_{{p , {\text{max}}}}^{ex}\)/J K−1 g−1 |
|---|---|---|---|---|---|
Calf leather | |||||
Chestnut tannina | 63.1 (2.1) | 66.3 (0.9) | 27.7 (2.2) | 3.2 (0.1) | 6.7 (0.2) |
Mimosa tannina | 70.8 (1.0) | 75.1 (1.1) | 29.5 (2.4) | 4.4 (0.2) | 5.1 (0.2) |
Sheep leather | |||||
Chestnut tannina | 66.5 (1.1) | 69.1 (1.3) | 26.8 (2.2) | 2.4 (0.2) | 8.6 (0.4) |
Mimosa tannina | 70.5 (1.0) | 73.6 (1.1) | 29.6 (2.4) | 3.4 (0.3) | 7.3 (0.2) |
Goat leather | |||||
Chestnut tannin | 66.8 (0.5) | 71.7 (1.1) | 26.5 (2.5) | 2.8 (0.2) | 6.9 (0.2) |
Mimosa tannin | 76.6 (0.3) | 79.6 (1.4) | 28.2 (1.5) | 2.9 (0.3) | 7.2 (0.2) |
Vegetable leather | 88.0b | 90.0b | 21.8b | – | – |
76.3c | 80.1c | 11.5c | – | – | |
Parchment | |||||
Calf | 53.1 (1.3) | 55.8 (1.8) | 53.4 (5.0) | 5.4 (1.2) | 5.8 (1.0) |
Sheep | 55.5 (0.6) | 57.4 (1.0) | 46.4 (2.4) | 4.6 (0.4) | 5.8 (0.5) |
Goat | 55.1 (0.7) | 57.6 (1.1) | 47.5 (3.1) | 3.6 (0.3) | 5.6 (0.4) |