## 3 Results and Discussion
### Mooney Viscosity and Relaxation Testing  
A related method for studying the rheology of blends is the measurement of viscosity, elasticity, and relaxation rate using a Mooney viscometer. This test, traditionally used to evaluate the processing properties of rubber compounds, can, however, be easily adapted to assess thermoplastic sealant blends. Although values exceeding 100 MU are generally considered high, no rotor or wall slippage was observed during the tests. The elasticity ratio (R\({}^{\prime}\)) and relaxation rate (k) were obtained from Mooney relaxation measurements (Table 4). R\({}^{\prime}\) indicates the degree of elastic recovery after deformation, while k represents the speed at which stored stress relaxed. Higher R\({}^{\prime}\) values suggested more elastic, network-like structures, whereas higher k values indicated faster stress dissipation and more fluid-like behavior. A description of the measurements and calculations of elasticity ratio R\({}^{\prime}\) and relaxation rate k can be found in [(39; 40)]. Figure 6 shows the Mooney viscosity ML changes depending on the modifier content. The addition of MPTES up to 2.5 PHR did not significantly affect the processing properties of the blends as the Mooney viscosity for samples MPTES-0 to MPTES-2.5 varied between 146.5 and 153.5 MU. As the concentration of MPTES in the systems increased, a noticeable reduction in Mooney viscosity was observed compared to the reference sample (MPTES-0). The measured Mooney viscosity values for MPTES-5 and MPTES-10 were 141.1 and 134.8, respectively, indicating a progressive decrease with higher MPTES content. In the presence of radicals in sample MPTES-10B, the IIR chain may have been grafted with MPTES and partially crosslinked during processing, as the viscosity increased to 138.1 compared to 134.8 MU for sample MPTES-10 and the R\({}^{\prime}\) elasticity increased from 1.38 to 1.4. At higher MPTES contents (5 and 10 PHR), a noticeable decrease in Mooney viscosity was accompanied by slight changes in R\({}^{\prime}\) and k. When a radical source was introduced (MPTES-10B), R\({}^{\prime}\) slightly increased again and relaxation slowed compared to the non-radical sample. In systems containing GLYEOS, APTES, and VTMOS, a similar decrease in viscosity was observed with increasing silane concentration. GLYEOS-10 exhibited a reduction of 21.4 compared to GLYEOS-0, APTES-10 showed a decrease of 21.24 relative to APTES-0, and VTMOS-10 demonstrated a decrease of 10.7 in comparison to VTMOS-0. The R\({}^{\prime}\) rate of GLYEOS samples decreased at a 1 PHR concentration but gradually increased to a maximum of 1.43 for samples containing 10 PHR and a radical source. The relaxation rate remained stable at 0-5 PHR concentrations but increased at 10 PHR. The introduction of VTMOS reduced the R\({}^{\prime}\) of the samples to a minimum of 1.26 at a 2.5 PHR concentration.  
\begin{table}
\begin{tabular}{c c c c c c c} \hline  & & & & **Density [g/cm\({}^{3}\)]** & \\ \hline
**Modifier/Content [\%]** & **0** & **1** & **2.5** & **5** & **10** & **10 + 0.1 B** \\ \hline MPTES & 1.44 & 1.44 & 1.44 & 1.44 & 1.43 & 1.44 \\ GLYEOS & 1.43 & 1.43 & 1.44 & 1.43 & 1.43 & 1.43 \\ VTMOS & 1.43 & 1.43 & 1.43 & 1.43 & 1.43 & 1.43 \\ APTES & 1.43 & 1.44 & 1.44 & 1.44 & 1.43 & - \\ \hline \end{tabular}
\end{table}
Table 3: Density changes depending on modifier content. Sample compositions in Table 1.