## 3 Results and Discussion
### Reaction Kinetics of Premixes  
It is known that adding various fillers generally increases the viscosity of the PUR foam mixtures, which can negatively affect the mixing of reactants, potentially slowing down the overall reaction rate [54]. The results of the main characteristic foaming times and dynamic viscosity are presented in Table 2.  
Unsurprisingly, the premises of PUR/Per and PUR/Verm foam composites negatively impacted cream, gel, and tack-free times--for instance, the addition of 2.5 wt.% Per and Verm increased cream time by 45% and 40% and gel time by 50% and 41%, respectively, compared to the control PUR foam premix. However, further addition of fillers improved the parameter, and at 10 wt.% Per and Verm concentration became almost the same as for the control premix. Similar observations can be made for PUR/PerDex and PUR/VermDex premixes, indicating that PerDex and VermDex fillers do not highly impact the cream and gel times, which are comparable to the premixes of PUR/Per and PUR/Verm foam \begin{table}
\begin{tabular}{c c c c c} \hline \multirow{2}{*}{**Premix**} & \multicolumn{4}{c}{**Parameter**} \\ \cline{2-5}  & **Cream Time, s** & **Gel Time, s** & **Tack-Free Time, s** & **Dynamic Viscosity, mPa\(\cdot\)s** \\ \hline Control PUR & 20 \(\pm\) 2 & 76 \(\pm\) 2 & 102 \(\pm\) 4 & 521 \(\pm\) 10 \\ PUR/Per-2.5 & 29 \(\pm\) 2 & 114 \(\pm\) 4 & 156 \(\pm\) 3 & 1456 \(\pm\) 15 \\ PUR/Per-5 & 22 \(\pm\) 2 & 110 \(\pm\) 2 & 159 \(\pm\) 2 & 3875 \(\pm\) 20 \\ PUR/Per-7.5 & 19 \(\pm\) 3 & 104 \(\pm\) 2 & 162 \(\pm\) 3 & 28,699 \(\pm\) 25 \\ PUR/Per-10 & 16 \(\pm\) 2 & 96 \(\pm\) 3 & 164 \(\pm\) 3 & 50,987 \(\pm\) 18 \\ PUR/Verm-2.5 & 28 \(\pm\) 1 & 107 \(\pm\) 2 & 140 \(\pm\) 2 & 2350 \(\pm\) 14 \\ PUR/Verm-5 & 24 \(\pm\) 2 & 100 \(\pm\) 3 & 165 \(\pm\) 2 & 7172 \(\pm\) 10 \\ PUR/Verm-7.5 & 21 \(\pm\) 2 & 94 \(\pm\) 3 & 197 \(\pm\) 3 & 34,569 \(\pm\) 15 \\ PUR/Verm-10 & 18 \(\pm\) 2 & 140 \(\pm\) 3 & 237 \(\pm\) 3 & 59,230 \(\pm\) 19 \\ PUR/PerDex-2.5 & 31 \(\pm\) 3 & 112 \(\pm\) 2 & 160 \(\pm\) 3 & 988 \(\pm\) 21 \\ PUR/PerDex-5 & 26 \(\pm\) 2 & 110 \(\pm\) 1 & 174 \(\pm\) 2 & 1798 \(\pm\) 18 \\ PUR/PerDex-7.5 & 20 \(\pm\) 3 & 110 \(\pm\) 2 & 181 \(\pm\) 3 & 2230 \(\pm\) 16 \\ PUR/PerDex-10 & 16 \(\pm\) 2 & 109 \(\pm\) 2 & 189 \(\pm\) 4 & 3042 \(\pm\) 19 \\ PUR/VermDex-2.5 & 30 \(\pm\) 2 & 99 \(\pm\) 2 & 179 \(\pm\) 3 & 652 \(\pm\) 5 \\ PUR/VermDex-5 & 28 \(\pm\) 3 & 98 \(\pm\) 3 & 184 \(\pm\) 2 & 1153 \(\pm\) 15 \\ PUR/VermDex-7.5 & 23 \(\pm\) 2 & 95 \(\pm\) 2 & 189 \(\pm\) 4 & 1690 \(\pm\) 12 \\ PUR/VermDex-10 & 20 \(\pm\) 3 & 94 \(\pm\) 2 & 195 \(\pm\) 2 & 2742 \(\pm\) 20 \\ \hline \end{tabular}
\end{table} 
Table 2: Reaction kinetics of control and fillers modified premixes. Figure 3: Proposed Verm and Per particles activation with Dex. composites. The obtained results are in excellent agreement with the ones obtained by [PERSON] et al. [29], who indicated that fillers similar to Verm and Per do not typically accelerate the initial stages of foam formation. However, the same conclusion cannot be made for tack-free time. The maximum tack-free times were observed for all PUR foam composites at 10 wt.% fillers concentrations, i.e., by 61% for PUR/Per, 132% for PUR/Verm, 85% for PUR/PerDex, and 91% for PUR/VermDex compared to the premix of control PUR foam. It means that all fillers interfere with the nucleation and growth of the bubbles, potentially altering the foaming kinetics. Therefore, a slower or less efficient foaming process can indirectly lead to a longer time for the surface to become tack-free. [PERSON] et al. [30] and [PERSON] et al. [55] showed that expanded Verm and Per can be used for oil absorption. Fillers with high oil absorption tend to increase viscosity more significantly, as can be seen from the results obtained in Table 2. In general, all premixes show the same behavior, i.e., a constant increase in viscosity with adding fillers.