Effect of additives on the thermal and thermo-oxidative stability of poly(ethylene furanoate) biobased polyester

Abstract Polyesters based on 2,5-furan dicarboxylic acid are a new class of biobased polymers with properties superior of those of their fossil-based homologues. However, similarly to poly(ethylene terephthalate) (PET), poly(ethylene 2,5-furan dicarboxylate) (PEF) degrades during its thermal processing and as a result its molecular weight drops, and discoloration occurs. This is mainly attributed to thermal and thermo-oxidative degradation reactions. The addition of several types of thermal stabilizers during the synthesis or the processing of thermoplastic polyesters is a common practice. In this work, a commercial phenolic antioxidant (Irganox 1098), and two phosphorus-containing thermal stabilizers (phosphoric acid and triphenyl phosphate) were added in PEF polyester during synthesis with the use of antimony acetate catalyst. The effect of these additives on the molecular weight, thermal properties, thermal, thermo-oxidative stability and physical aging of PEF was evaluated. It was found that all additives slightly improved the thermal stability of PEF, with phosphoric acid and mainly triphenyl phosphate being the most efficient ones.