## 3 Results and Discussion
### Water Resistance Performance
However, Figure 7b shows that the addition of VermDex reduced the N=C=O intensity to a minimum, resulting in the formation of complete urethane linkages. The band at 1725 cm\({}^{-1}\) indicate the stretching vibrations of C=O, while intensities at 1595 cm\({}^{-1}\) and 1514 cm\({}^{-1}\) are attributed to C-C and N-H bending, respectively. Interestingly, the FTIR spectra of PUR/VermDex-10 foam composites (Figure 7b) are characterized by an additional band at 1074 cm\({}^{-1}\), which is attributed to Si-O-Si. It is considered that a chemical reaction has occurred between VermDex particles and the PUR matrix. However, no changes in the FTIR spectra of PUR/PerDex-10 (Figure 7a) are visible. The possible reaction of Dex-activated fillers and polyol with isocyanate is graphically presented in Figure 8. The graphical representation shows that Dex-activated fillers have hydroxyl groups incorporated on their surface, which, together with the hydroxyls from polyol, successfully react with an excess of isocyanate, thus forming urethane linkages with the incorporated fillers in PUR chains. The statistical analysis of short-term water absorption of PUR foam composites with 2.5 wt.% different fillers showed (Figure 6a) that there are no differences between the PUR/Per-2.5, PUR/Verm-2.5, and PUR/VermDex-2.5 foam composites. The F-criterion is 0.066, \(p=0.94\), and R\({}^{2}=0.0216\). However, a significant difference occurs between the aforementioned PUR foam composites and control PUR as well as PUR/Perdex-2.5. When comparing the PUR/PerDex-2.5 foam composite with the control PUR, the analysis showed that there is no difference between the average values of short-term water absorption. The F-criterion statistic is 0.31, \(p=0.61\), and R\({}^{2}=0.0714\). Further, the statistical analysis of the short-term water absorption of PUR foam composites with 5 wt.% different fillers showed (Figure 6b) that there are no differences between the PUR/Per-5 and PUR/VermDex-5 foam composites. The F-criterion is 0.0, \(p=1.0\), and R\({}^{2}=0\). Comparing PUR/Verm-5 and PUR-PerDex-5, the statistical analysis showed a statistically insignificant difference in the results. The F-criterion is 1.25, \(p=0.33\), and R\({}^{2}=0.238\). However, significant differences were observed between PUR/Per-5 and PUR/VermDex-5 and PUR/Verm-5 and PUR/PerDex-5 foam composites. In addition, all PUR foam composites with 5 wt.% fillers had significant difference in short-term water absorption compared to control PUR. Moreover, the statistical analysis of the short-term water absorption of PUR foam composites with 7.5 wt.% different fillers showed (Figure 6c) that there are no differences between the PUR/Per-7.5 and PUR/VermDex-2.5. The F-criterion is 0.0, \(p=0.94\), and R\({}^{2}=0.0216\). However, the statistical analysis of the short-term water absorption of PUR foam composites with 7.5 wt.% different fillers showed (Figure 6d) that there are no differences between the PUR/Per-7.5 and PUR/VermDex-2.5. The F-criterion is 0.0, \(p=0.94\), and R\({}^{2}=0.0216\). However, the statistical analysis of the short-term water absorption of PUR foam composites with 7.5 wt.% different fillers showed (Figure 6e) that there are no differences between the PUR/Per-7.5 and PUR/VermDex-2. PUR/Verm-7.5 foam composites. The F-criterion is 0.64, \(p\) = 0.47, and R\({}^{2}\) = 0.138. Statistically significant differences were observed between PUR/Per-7.5 and PUR/Verm-7.5 and control PUR, PUR/PerDex-7.5, and PUR/VermDex-7.5. Lastly, the statistical analysis of the short-term water absorption of PUR foam composites with 10 wt.% different fillers showed (Figure 6d) that there were no differences between the PUR/Verm-10 and PUR/VermDex-10 foam composites. The F-criterion statistic is 0.10, \(p\) = 0.78, and R\({}^{2}\) = 0.0244. When comparing the control PUR and PUR/Verm-10 and PUR/Vermdex-10 foam composites, the analysis showed that there was no difference between the mean values of short-term water absorption. The F-criterion is 0.39, \(p\) = 0.69, and R\({}^{2}\) = 0.114.