# Doped Epoxy Resins as an Alternative to Luminescent Optical Sensors
## 3 Results and Discussion
### Thermal and Spectroscopic Analysis
All the earlier ones may indicate incomplete polymerization of monomers, which are released from the tangled structure of the polymer at elevated temperatures, and their earlier decomposition occurs. The same applies to incompletely polymerized active solvent molecules. However, the initial mass loss and the corresponding maxima recorded on the DTG and DSC curves are most likely related to the presence of water physically adsorbed on the surface. The hygroscopic properties of the analyzed materials should be taken into account, which, based on the mass loss value, would indicate that the samples No.1-60 showed the greatest properties in question. Mass spectroscopy helps in the interpretation of changes that occur in a sample subjected to a temperature regime. Based on this, it is possible to determine what gases and at what temperature are released when the sample is heated (information about thermal decomposition pathways) [41; 47; 48]. Due to the multitude of ions appearing during the entire analysis, the article includes collective ion mass charts, i.e., the so-called ion current (Figure 2). The analysis of spectroscopic spectra indicates that for samples No.1-15 up to a temperature of 170 \({}^{\circ}\)C, for the mass loss only water is responsible (as indicated by the presence of ions \(m/z\) = 17-19). Above this temperature, ions \(m/z\) = 26-29 begin to appear, responsible for the presence of CH\({}_{2}\)=C\({}^{+}\), CH\({}_{2}\)=CH\({}_{2}^{+}\) (terminal vinyl group), CO or CH\({}_{3}\)CH\({}_{2}^{+}\). Above the mentioned temperature, ions \(m/z\) = 42-44 also appear, responsible for the presence of groups: CH\({}_{2}\)=CH-CH\({}_{3}^{+}\), CH\({}_{2}\)=C=\({}^{+}\), CH\({}_{3}\)-C=\({}^{+}\) and H\({}_{2}\)N-C=O+ (a carboxyl group is also possible). The mentioned ions are most likely related to the presence of an active solvent in the composition, which is the first to be released from the still relatively stiff polymer structure at elevated temperatures, and at first undergo thermal \begin{table}
\begin{tabular}{c c c c c c c c c c c c c} \hline \hline \multirow{2}{*}{**Sample**} & \multicolumn{4}{c}{**Temperature at Mass**} & \multicolumn{4}{c}{**DTGmax\({}^{f}\)C**} & \multicolumn{4}{c}{**DSC\({}_{\text{max}J}\)\({}^{c}\)C**} & \multirow{2}{*}{**Residual**} \\  & \multicolumn{4}{c}{**Loss/\({}^{c}\)C**} & & & & & & & & **Mass/wt.\%** \\ \cline{2-13}  & **1/wt.\%** & 3/wt.\%** & 5/wt.\% & **I** & **II** & **III** & **IV** & **I** & **II** & **III** & **IV** \\ \hline Sample No.15-15 & 92.7 & 133.4 & 159.1 & 183.7 & -* & 227.3 & 421.9 & 125.3 & 182.7/ & 373.1 & 398.5/426.8 & 11.4 \\ Sample No.15-30 & 109.1 & 149.4 & 179.1 & 196.2 & -* & 239.8 & 420.6 & 129.1 & 192.3/ & 375.5 & 395.5/415.1/ & 11.8 \\ Sample No.15-60 & 102.1 & 142.3 & 171.9 & 194.4 & -* & 234.7 & 421.7 & 129.6 & 223.8 & 376.6 & 409.7/424.0 & 16.5 \\ \hline Sample No.16-15 & 108.9 & 145.7 & 172.2 & 171.7 & -* & -* & 421.8 & 189.5 & 222.5/ & 368.4 & 425.1 & 15.0 \\ Sample No.16-30 & 91.9 & 132.4 & 160.7 & -* & -* & 230.8 & 421.5 & 122.8 & 229.5 & -* & 425.5 & 10.2 \\ Sample No.16-60 & 92.4 & 137.3 & 171.3 & 122.7 & 195.4 & 246.3 & 422.6 & 192.8 & 226.5/ & -* & 422.6/432.4 & 12.2 \\ \hline Sample No.17-15 & 94.0 & 135.1 & 160.9 & -* & -* & 200.5 & 419.9 & -* & 206.9 & 379.3 & 409.3/424.5 & 13.6 \\ Sample No.17-30 & 106.8 & 145.9 & 173.1 & 166.2 & -* & 207.5 & 420.8 & 210.8 & -* & 377.4 & 400.9/422.4 & 13.0 \\ Sample No.17-60 & 90.9 & 138.7 & 172.9 & 109.7 & -* & 216.3 & 421.7 & 200.3/ & 265.3 & -* & 406.7/421.8/ & 12.6 \\ Sample No.18-15 & 92.9 & 129.9 & 155.2 & 188.6 & -* & 235.2 & 421.1 & 125.3 & 226.2 & -* & 420.7/427.4 & 12.2 \\ Sample No.18-30 & 114.9 & 159.4 & 189.8 & 130.3 & -* & 238.0 & 420.6 & 125.3 & 193.7/ & -* & 413.8/423.2 & 13.2 \\ Sample No.18-60 & 98.9 & 146.0 & 180.2 & 148.6 & -* & 237.3 & 421.7 & 125.3 & 191.7/ & -* & 407.0/422.2 & 13.8 \\ \hline \hline \end{tabular}
* *---no effect was observed.  
\end{table} 
Table 4: _Cont._decomposition.