## 3 Results  
### Physicochemical Characterization  
The results of the physicochemical characterization of the 10 samples that were studied are shown in Table 3. \begin{table}
\begin{tabular}{l c c c c c c c c c} \hline
**TEST** & **1** & **2** & **3** & **4** & **5** & **6** & **7** & **8** & **9** & **10** \\ \hline Substances soluble in dichloromethane & 3.8 & 4.0 & 7.1 & 23.0 & 29.1 & 2.4 & 10.2 & 8.1 & 8.7 & 11.7 \\ Water and volatile content & 11.3 & 12.8 & 9.8 & 6.1 & 3.0 & 1.3 & 10.7 & 9.9 & 10.5 & 10.4 \\ Extractable organic & & & & & & & & & \\ and inorganic matter & 1.8 & 0.08 & 0.06 & - & - & - & 0.08 & 0.09 & 0.2 & 0.3 \\ Inorganic matter & 0.1 & 0.06 & 0.5 & - & - & - & 0.08 & 0.08 & 0.2 & 0.2 \\ Ash and insoluble mineral & 12.8 & 5.5 & 5.5 & 15.1 & 15.1 & 2.4 & 0.5 & 0.6 & 1.3 & 1.5 \\ Nitrogen and leather & & & & & & & & & \\ Nitrogen & 11.3 & 13.0 & 13.0 & 5.3 & 5.3 & 1.9 & 12.8 & 13.2 & 12.1 & 11.8 \\ Leather substance & 63.5 & 72.8 & 72.81 & 29.9 & 29.9 & 10.4 & 71.9 & 74.2 & 68.06 & 66.1 \\ pH and difference index & & & & & & & & & \\ pH & 4.5 & 3.7 & 3.7 & 4.2 & 4.2 & 5.8 & 3.0 & 3.0 & 3.2 & 3.3 \\ Difference index & - & - & - & - & - & - & - & - & - & - \\ Formaldehyde & 10.5 & \(<\)10 & \(<\)10 & \(<\)10 & \(<\)10 & \(<\)10 & 9.0 & \(<\)5 & \(<\)10 & \(<\)10 \\ Titanium (Tl) & \(<\)12 & \(<\)12 & 12.2 & 449 & \(<\)12 & 133 & \(<\)12 & \(<\)12 & \(<\)12 \\ Aluminum (Al) & 102 & 339 & 247 & 3948 & 244 & 153 & 102 & 38.0 & 66.9 & 77.1 \\ Zirconium (Zr) & \(<\)12 & \(<\)12 & \(<\)12 & \(<\)12 & \(<\)12 & \(<\)12 & \(<\)12 & \(<\)12 & \(<\)12 \\ Chromium (Cr) & 25,079 & 18,034 & 215 & 9179 & \(<\)3 & \(<\)3 & 11.3 & 11.1 & 1127 & 1121 \\ Zinc (Zn) & \(<\)3 & \(<\)3 & \(<\)3 & \(<\)3 & \(<\)3 & \(<\)3 & \(<\)3 & \(<\)3 & \(<\)3 \\ Iron (Fe) & 38.6 & 60.7 & 217 & 26,377 & 48.7 & 10.8 & 38.3 & 31.3 & 57.4 & 71.5 \\ Tensile strength & & & & & & & & & \\ Strength & 25.4 & 25.39 & 32.32 & 5.50 & 5.10 & 9.48 & 38.37 & 35.86 & 18.35 & 21.04 \\ Elongation & 79.8 & 79.75 & 45.45 & 4.63 & 33.47 & 15.77 & 70.35 & 62.0 & 64.50 & 68.20 \\ Tear load & 41.1 & 41.11 & 67.50 & 7.12 & 68.12 & 47.74 & 145.67 & 140.83 & 77.36 & 78.65 \\ Distension and strength of & & & & & & & & & \\ surface & Thickness & 1.14 & 1.27 & 2.20 & 0.34 & 1.59 & 1.28 & 1.75 & 1.83 & 1.81 & 1.86 \\ Break & & & & & & & & & & \\ Strength & 34.8 & 20.5 & 55.0 & 1.1 & 23.5 & 17.6 & 62.9 & 51.9 & 25.1 & 26.9 \\ Distension & 12.0 & 6.2 & 8.5 & 4.1 & 10.6 & 10.9 & 11.0 & 9.6 & 9.0 & 9.5 \\ Burst & & & & & & & & & & \\ Strength & 45.9 & 52.3 & 102.1 & 1.1 & 23.5 & 17.6 & 105.6 & 97.5 & 49.8 & 64.8 \\ Distension & 14.3 & 11.1 & 13.2 & 5.7 & 10.6 & 11.6 & 14.3 & 13.3 & 12.8 & 14.1 \\ Water vapor permeability & 4.9 & 4.0 & 1.1 & 0.4 & 6.8 & 0 & 5.9 & 7.7 & 10.1 & 9.9 \\ Shrinkage temperature & 106 & 107 & 81 & \(>\)140 & \(>\)140 & \(>\)140 & 68 & 69 & 72 & 71 \\ Flex resistance & & & & & & & & & \\ Dry, 100,000 cycles & & Wrinkles & Wrinkles & Wrinkles & Breaks & Wrinkles & Wrinkles & Wrinkles & Wrinkles \\ Wet, 50,000 cycles & Wrinkles & Wrinkles & Wrinkles & Breaks & Wrinkles & Breaks & Wrinkles & Wrinkles & Wrinkles \\ Light fastness & 7 & \(>\)7 & \(>\)7 & \(>\)7 & \(>\)7 & \(>\)7 & 3–2 & 2–3 & 4–5 & 4–5 \\ Accelerated aging color & & & & & & & & & & \\ change & & & & & & & & & & \\
50 \({}^{\circ}\)C, 90\%HR for 96 h & 5 & 5 & 4–5 & 5 & 5 & 4 & 3–4 & 4–5 & 4 \\ Rub fastness & & & & & & & & & & \\ Dry, 100 cycles & 4–5 & 1–2 & 3–4 & 5 & - & 5 & 4 & 4 & 4–4 & 4–5 \\ Wet, 20 cycles & 4 & 3 & 3–4 & 4–5 & - & 4–5 & 3 & 2–3 & 4–5 & 4–5 \\ Finishing adhesion & & & & & & & & & & \\ Dry & 18.3 & 6.9 & 14.2 & Leather & Leather & 41.8 & 51.1 & 64.7 & 37.3 & 39.5 \\ Wet & 17.5 & 6.5 & 14.2 & Leather & 46.1 & 42.7 & 44.4 & 50.9 & 23.4 & 27.4 \\ \end{tabular}
\end{table} 
Table 3: Characterization of the 10 samples under study. As shown in Table 3, leatherette (#4) and Pinatex (#5) materials have a high content of substances extractable in dichloromethane.