Ferulic acid-based bis/trisphenols as renewable antioxidants for polypropylene and poly(butylene succinate)
Résumé
Green chemistry principles recommend the use of renewable feedstocks and biocatalysis to decrease environmental impact of chemicals manufacturing. In this scope, three ferulic acid-based bisphenols and one trisphenol were synthesized using enzymatic catalysis. Their antioxidant activity at polymer processing and service temperature was investigated in polypropylene (PP) and polybutylene succinate (PBS), and benchmarked against the commercial antioxidant Irganox 1010. The analysis of the oxygen induction time of the polymer degradation at high temperatures showed that Irganox 1010 was more efficient to protect PP than the ferulic acid-based bis/trisphenols, whereas, in the case of PBS, the biobased antioxidants, and in particular tris-O-dihydroferuloyl glycerol (GTF), were more efficient. FT-IR analysis of neat and formulated PP with different antioxidants stored for 2 years at room temperature showed no degradation. Aging studies of PBS at room temperature in dry atmosphere showed that all antioxidants had an equal stabilizing effect on the molecular weight averages of the polymer. In conclusion, ferulic acid-based antioxidants can be efficient primary antioxidants for the thermo-oxidative stabilization of polymers.