## 3 Results and Discussion
### MALDI-TOF Analysis
\begin{table}
\begin{tabular}{c c c c c c c c c c c c c c} \hline \hline
**Epoxidation Degree** & \multicolumn{2}{c}{**ED0**} & \multicolumn{2}{c}{**ED1**} & \multicolumn{2}{c}{**ED2**} & \multicolumn{2}{c}{**ED3**} & \multicolumn{2}{c}{**ED4**} & \multicolumn{2}{c}{**ED5**} & \multicolumn{2}{c}{**ED6**} \\ \hline Oligomer & aNa & aDHB & aNa & aDHB & aNa & aDHB & aNa & aDHB & aNa & aDHB & aNa & aDHB \\ Monomer & 251.28 & 382.41 & 307.35 & 438.48 & 363.31 & 494.44 & - & - & - & - & - & - \\ Dimer & 491.58 & 622.71 & 547.65 & 678.78 & 603.71 & 734.84 & 699.78 & 790.91 & 715.84 & 846.97 & - & - & - \\ Trimer & 731.88 & 863.01 & 787.95 & 919.08 & 844.01 & 975.14 & 900.08 & 1031.21 & 996.14 & 1087.27 & 1012.21 & 1143.34 & 1068.27 & 1199.4 \\ Tetramer & 972.19 & 1103.32 & 1028.25 & 1159.38 & 1084.31 & 1215.44 & 1140.38 & 1271.51 & 1196.44 & 1327.57 & 1252.51 & 1383.64 & 1308.57 & 1439.7 \\ Pentramer & 1212.49 & 1343.62 & 1268.55 & 1399.68 & 1326.42 & 1455.75 & 1380.68 & 1511.81 & 1346.74 & 1567.87 & 1492.81 & 1623.94 & 1548.87 & 1680 \\ Hexamer & 1452.79 & 1583.92 & 1508.58 & 1563.98 & 1564.92 & 1696.05 & 1620.98 & 1752.11 & 1677.05 & 1808.18 & 1733.81 & 1864.24 & 1789.18 & 1920.31 \\ \hline
**Epoxidation Degree** & \multicolumn{2}{c}{**ED7**} & \multicolumn{2}{c}{**ED8**} & \multicolumn{2}{c}{**ED9**} & \multicolumn{2}{c}{**ED10**} & \multicolumn{2}{c}{**ED11**} & \multicolumn{2}{c}{**ED12**} & \multicolumn{2}{c}{**ED12**} \\ \hline Oligomer & aNa & aDHB & aNa & aDHB & aNa & aDHB & aNa & aDHB & aNa & aDHB & aNa & aDHB & \\ Tetramer & 1364.64 & 1495.77 & 1420.7 & 1551.83 & - & - & - & - & - & - & - & - & - \\ Pentramer & 1604.94 & 1736.07 & 1661 & 1792.13 & 1717.07 & 1848.2 & 1773.13 & 1904.26 & - & - & - & - \\ Hexamer & 1845.24 & 1976.37 & 1901.3 & 2032.43 & 1960.37 & 2091.5 & 2011.42 & 2142.55 & 2069.5 & 2200.63 & 2125.56 & 2256.69 \\ \hline \hline \end{tabular}  
* Mass peaks unit = Daltoris; aNa = Mass peaks values of sodium adducts; aDHB = Mass peaks values of dithiokrybenzoic acid adducts.  
\end{table} 
Table 2: Mass peaks as a function of the oligomer size versus adducts with sodium and DHB. Observing the spectra (Figures 8 and 9), there are significant concentrations of the dimer ED4 (715/716 Da) at all the samples. Some samples showed in their composition, the dimer ED0 (491/492 Da). In this case, it can be considered as a contaminant in the mixture because this structure does not have epoxy groups to support crosslinking. In all samples, considerable concentrations of the trimer ED6 (1068/1069 Da) were present in their composition. Also, all the samples showed traces of the tetramers ED7 (1365/1366 Da) and ED8 (1420/1421 Da). An important characteristic was that the samples EPR-S2_c and EPR-S2_f contained several traces of secondary products (oligomers not epoxidized entirely) in the region of 500-1000 Da, which affects the physical-chemical properties. Thus, although the samples theoretically have the same composition, due to the findings, it is probable that their physical-chemical properties are not the same. Also, a significant characteristic to observe is the influence of the incomplete oligomers in the photoresists. The spectra in Figures 13 and 14 present the amount of the oligomers and the incomplete oligomers for the different samples. Figure 12: Oligomers structures related to the mass peaks at MALDI-TOF analysis. The samples presented different compositions mainly in the dimers and trimers (Figure 13) and in the non-epoxidized dimers (dimers ED0, Figure 14) (e.g., EPR-S2_b and EPR-S2_c are the most concentrated with respect to dimers ED0; the sample EPR-S2_c shows almost four times higher concentration than the other samples). The samples of EPR-S1 contain a small amount of dimer ED0. It is important to mention that the concentration of the dimers ED0 in the samples is comparable to the epoxidized oligomers with respect to the intensity values.