LAUSR

Abstract Aromatic poly(ester amide)s comprising of α-amino acids and lignin-derived building blocks were synthesized and their thermal properties assessed. The polymers, which were prepared by melt polycondensation with p-toluenesulfonic acid as the catalyst, all possessed high thermal stability in N2; the onsets of thermal degradation (Td onset) were >320 °C, the percent char yields ranged from 40 to 65% at 800 °C, and the glass transition temperatures (Tg) ranged from 136 °C–238 °C. Remarkably, the polymers were also thermally stable in air, with the Td onsets >330 °C and Td 50% >520 °C. Interestingly, the size of the R-group on the amino acids greatly affected the Tg, but only minimally affected the Td; perhaps due to the variation in polymer size. Wide angle x-ray diffraction measurements (WAXS) revealed semi-crystalline polymers, with similar diffraction patterns for all the polymers. The polymers mostly maintain their thermal stability after being subjected to various pH media for 6 days at 50 °C. Altogether, these characteristics make our bio-based PEAs worthwhile candidates for continued investigation as alternatives to petrochemical-derived thermoplastics for high performance materials.