## 3 Experimental Results  
Figure 1A shows a comparison between the dynamic rheological scan of the UF matrix with and without the catalyst. As it can be observed, the resin without the catalyst shows an initial decrease of the viscosity, due to the decrease of water viscosity. At about 120 \({}^{\circ}\)C, the viscosity increase indicates the onset of the curing reaction. For the system with the catalyst, the characteristic temperature of the viscosity increase is shifted at about 60 \({}^{\circ}\)C, evidencing a reduction of the onset curing temperature. \begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline \multirow{2}{*}{**Formulation**} & \multirow{2}{*}{**Water (\%)**} & \multirow{2}{*}{**P100N (\%)**} & \multicolumn{2}{c}{**Dried OFMSW**} & \multicolumn{2}{c}{**Catalyst**} & \multicolumn{2}{c}{**Coffee Powder**} & \multicolumn{2}{c}{**Sawdust**} & \multicolumn{2}{c}{**Sodium**} \\  & & & **(\%)** & **(\%)** & **(\%)** & **(\%)** & **(\%)** & **Bicarbonate (\%)** \\ \hline OF\_P100N & 30 & 57 & 13 & 0 & 0 & 0 & 0 \\ OF\_P100N\_C & 25 & 47.5 & 10.8 & 16.7 & 0 & 0 & 0 \\ OF\_P100N\_C\_10c & 25 & 37.5 & 10.8 & 16.7 & 10 & 0 & 0 \\ OF\_P100N\_C\_5s & 25 & 42.5 & 10.8 & 16.7 & 0 & 5 & 0 \\ OF\_P100N\_C\_10s & 25 & 37.5 & 10.8 & 16.7 & 0 & 10 & 0 \\ OF\_P100N\_C\_15s & 25 & 32.5 & 10.8 & 16.7 & 0 & 15 & 0 \\ OF\_P100N\_C\_1 ab & 25 & 46.5 & 10.8 & 16.7 & 0 & 0 & 1 \\ OF\_P100N\_C\_2 sb & 25 & 45.5 & 10.8 & 16.7 & 0 & 0 & 2 \\ OF\_P100N\_C\_3 ab & 25 & 44.5 & 10.8 & 16.7 & 0 & 0 & 3 \\ OF\_P100N\_C\_5 sb & 25 & 42.5 & 10.8 & 16.7 & 0 & 0 & 5 \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Weight composition of formulations. In order to evaluate the curing time at 60 \({}^{\circ}\)C, an isothermal rheological test was also performed on catalyzed systems, in the presence and absence of the OFMSW (samples P100N_C; OF_P100N_C, respectively). The results reported in Figure 1B show that a curing time of 1 h is enough for both mixtures to complete the reaction, even in presence of the OFMSW. In order to evaluate the effect of the presence of different recycled additives on the curing process of the catalyzed UF/OFMSW blends, dynamic rheological analyses of all the formulations of Table 1 were also performed. The results reported in Figure 2 for the blends at 10% of coffee and sawdust show that the onset curing temperature is not significantly modified by the addition of coffee or sawdust, indicating that a temperature of 60 \({}^{\circ}\)C could be selected for the curing process for each of the produced blends. Therefore, starting from these preliminary rheological results, an optimal curing cycle was assessed, i.e., T = 60 \({}^{\circ}\)C and t = 1 h, instead of T = 120 \({}^{\circ}\)C and t = 1 h, used in the previous paper [1]. The reduction of the curing temperature is made possible through the use of a proper catalyst. Figure 1: (**A**) Rheological dynamic curves of the P100N and P100N_C samples; (**B**) isothermal curves of the P100N_C and OF_P100N_C samples at 60 \({}^{\circ}\)C.  
Figure 2: Rheological dynamic curves of the OF_P100N_C samples in the presence and absence of additives: Viscosity (\(\eta\)) as a function of temperature (T). The pictures of some of the blends produced, before and after the curing process are reported in Figure 3. Initially, the mixing of the resin, catalyst, OFMSW, and water results in a relatively low viscosity slurry, which can be easily poured into a silicon mold (Figure 3A). This is a distinct advantage of the developed process, since in any case a pressure-free process was used for the sample production. In Figure 3B, after curing, the solid samples are obtained. Compression tests were performed on the cured samples; results reported in Figure 4A,B show the effect of the addition of coffee or sawdust, respectively, on the stress stain curves.