## 3 Results
### Hydrophobic Properties  
The surface hydrophobicity of the produced samples was determined by measuring three parameters: water contact angle (WCA), contact angle hysteresis (CAH), and roll-off angle (RoA). The values of these parameters are presented in Table 3.  
The reference sample, an unmodified epoxy-silicone resin, obtained a WCA of 80 \(\pm\) 1\({}^{\circ}\) and hence may be considered hydrophilic (WCA \(<\) 90\({}^{\circ}\)). Analyzing the WCA values of the coatings after the chemical modification, it can be concluded that the double functionalization of polysiloxanes caused an increase in the WCA values. Nevertheless, the increase was not significant. The range of the WCA values for the modified samples was from 84\({}^{\circ}\) to 90\({}^{\circ}\). Taking into account the measurement uncertainty, it can be concluded that the samples modified with the MOD2, MOD3, and MOD4 additives presented surfaces at the boundary between hydrophilicity and hydrophobicity, obtaining WCA values close to 90\({}^{\circ}\). The lowest increase in WCA compared to the reference sample was recorded for the sample modified with MOD1. Figure 7 shows a picture of a water droplet applied on the surface of a MOD4-modified sample, which achieved the highest WCA value. The unmodified sample achieved a CAH value of 22 \(\pm\) 2\({}^{\circ}\). The chemical modifications caused a significant decrease in this parameter. All modified samples obtained similar results, and the CAH range was from 7\({}^{\circ}\) to 11\({}^{\circ}\). The lowest value was recorded for the sample modified with MOD2 polysiloxane, for which CAH decreased by 59% compared to that of the reference coating. The RoA parameter also significantly decreased after modification with polysiloxanes. The reference sample obtained an RoA of 75 \(\pm\) 8\({}^{\circ}\), and the modified samples achieved RoA values in the range from 32\({}^{\circ}\) to 55\({}^{\circ}\). The lowest RoA values were obtained for MOD3- and MOD4-modified samples, with a reduction of about 55% compared to the RoA of the reference sample. In summary, double-functionalized polysiloxanes showed increased water contact angle values (despite not crossing the boundary between hydrophobicity and hydrophilicity) and a significant reduction in contact angle hysteresis and roll-off angle values for all types of modifications. Water Contact Angle at Temperatures Below 0 \({}^{\circ}\)C  
Figure 8 shows the values of WCA measured at four temperatures below 0 \({}^{\circ}\)C to determine how a temperature reduction affected the surface hydrophobicity. Figure 7: The picture of a water droplet applied on the surface of a MOD4-modified sample. Analyzing the results, it can be seen that the reference sample as well as all modified samples recorded a decrease in the WCA values at reduced temperatures compared to the values determined at room temperature. In addition, for some of the modifications, a relationship can be observed, i.e., the lower the test temperature, the lower the WCA values. The highest reduction in WCA, i.e., a reduction in the hydrophobic properties of the surface, was recorded for the sample modified with MOD3; at the temperatures of \(-10\)\({}^{\circ}\)C and \(-15\)\({}^{\circ}\)C, the WCA value decreased by 27% compared to the WCA value at room temperature. On the other hand, the highest hydrophobic stability at low temperatures was shown by the sample modified with polysiloxane MOD1, obtaining only a decrease in WCA equal to about 5% compared to the room temperature value. Moreover, for this sample, no further decrease in WCA was observed with the decreasing temperature, the WCA values determined at temperatures from \(0\)\({}^{\circ}\)C to \(-15\)\({}^{\circ}\)C being either the same or close to each other. The reference sample also experienced a low decrease in the WCA values at reduced temperatures, as the reduction was equal to 8% compared to the WCA determined at room temperature.