Processing properties and pyrolysis behavior of novolak-hexamethylenetetramine mixtures

Figures & data

Figure 1. Microgel formation in thermoset polymers during curing, adapted from Vidil et al. [43]. The large orange circles indicate the microgel islands in the phenolic resin melt.

Figure 2. Complex viscosity of Bakelite 0235 mixtures from 100 °C to 170 °C.

Figure 3. Complex viscosity of Bakelite 6109 mixtures from 100 °C to 170 °C.

Figure 4. Gap distance evolution of Bakelite 0235 mixtures from 100 °C to 170 °C.

Figure 5. Gap distance evolution of Bakelite 6109 mixtures from 100 °C to 170 °C.

Figure 6. Influence of hexa content on the minimal complex viscosity for Bakelite 0235 and Bakelite 6109.

Figure 7. Influence of heating rate on curing behavior of Bakelite 0235 mixtures from 100 °C to 170 °C.

Figure 8. TG mass loss curves for Bakelite 0235 mixtures up to 1000 °C.

Figure 9. Asymptotical fit of residual carbon amount of Bakelite 0235 and Bakelite 6109 at 1000 °C.

Figure 10. DTG mass loss curves for Bakelite 0235 mixtures up to 1000 °C.

Figure 11. DTG curve for Bakelite 0235 mixture with 3 wt.-% hexa up to 1000 °C. Four kinetically important mass loss steps were detected at 100 °C, 270 °C and 400 °C and 550 °C.

Figure 12. FTIR spectra of pyrolysis gas emitted by Bakelite 0235 mixture with 3 wt.-% hexa at 100 °C, 270 °C and 400 °C and 550 °C.

Figure 13. Total ion current chromatogram (TICC) for Bakelite 0235 mixtures at 400 °C and 550 °C.

Figure 14. Total ion current chromatogram (TICC) for Bakelite 0235 + 3 wt.-% hexa at temperatures of 400 °C and 550 °C. Chemical substances were assigned to each peak by comparing measured mass spectra to chemical database spectra.

Figure 15. Schematic illustration of hexa induced microgel formation in novolak resins.

Figure 16. Minimal complex viscosity plotted over char yield for different hexa contents; A linear fit for hexa contents $\le$ 9 wt.-% and an exponential fit for hexa contents $\ge$ 9 wt.-% was used to fit the data for Bakelite 0235 derived resins.

Vidil T, Tournilhac F, Musso S, et al. Control of reactions and network structures of epoxy thermosets. Prog Polym Sci. 2016;62:126–179.

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Data availability statement

The authors confirm that the data supporting the findings of this study are available within the article and its supplementary materials.