Pom Degradation Report

In general, the melt-mixing process induces thermal and thermo-oxidative degradation. Formaldehyde is oxidized to formic acid accelerating the degradation of POM via acidolysis.[4] As mentioned above the addition of bisphenol-A and aniline during the melt-mixing process of POM, allowed the reaction with formaldehyde and generated BA-a and poly(BA-a). At that time, the balance between the formaldehyde consumption to obtain BA-a and the released formaldehyde during thermal degradation of POM is the key point to retard the exposure of formaldehyde to the surroundings.
Thermal stability based on formaldehyde releasing temperature and POM degradation temperature is important information to evaluate how an in-situ BA-a formation in POM efficiently

The use of TG-FITR was applied so that the degradation temperature and the component generated at that stage can be trace. Figure 3a shows the pristine POM starts showing the formaldehyde peak (CH2O at 1745 cm-1 and 2800 cm-1) at 289 C. As POM-B05A10 was prepared under the condition that POM was molten, the consideration of POM degradation had better reply on the POM after melting, so-called the thermal treated POM, than the pristine POM. Figure 3b shows the thermal treated POM starts to generate formaldehyde at 251C which is much lower than the pristine POM. This implies the ease of formaldehyde generation if the pristine POM was once thermally treated. However, in the case of POM-B05A10, the formaldehyde release is observed at as high as 338 C (Figure 4A) which is 87 C higher than those of POM and thermally treated POM. It is also important to mention that the POM-B05A10 degrades at 431 C which is much higher than that of pristine POM (378 C). This suggests that during in-situ reactive blend of bisphenol-A, aniline, and POM, the formaldehyde released at that melt blend process was effectively entrapped to form

The curve fitting analysis of FTIR spectra was carried out. The ring opening of poly(BA-a) could be observed from the disappearance of C-O-C (1233 cm-1). Thus, the integral ratio of the C-O-C (1233 cm-1) over those of the CH stretching (2690 cm-1) was analyzed and shown in Figure S3. It is clear that the poly(BA-a) increases with increasing bisphenol-A content. It might be during the melt-mixing process, by increase in bisphenol-A and aniline content, the formation of BA-a was increased, at that time the oxazine ring-opening polymerization occurred. These lead to increasing