Insights into the Synthesis of Poly(ethylene 2,5-Furandicarboxylate) from 2,5-Furandicarboxylic Acid: Steps toward Environmental and Food Safety Excellence in Packaging Applications

Poly­(ethylene 2,5-furandicarboxylate) (PEF) is considered today as a very promising biobased polymer for packaging applications. Most often, scientific literature describes synthetic procedures based on the transesterification of the dimethylester of the 2,5-furandicarboxylic acid, whereas this paper aims at studying the possibility of a practical and profitable synthetic route for PEF comprising a direct esterification stage of 2,5-furandicarboxylic acid. In that respect two catalysts, zinc acetate and aluminum acetylacetonate, chosen for their compatibility with food contact applications and for featuring a potentially reduced environmental impact, were investigated. The synthesis was performed by using tight reaction conditions: low excess of diol and short reaction time. Interesting results were obtained in terms of final PEF viscosity, color, and diethylene glycol content, that may strongly influence thermal and barrier properties. Furthermore, the obtained amorphous polymers are potentially suitable for the manufacturing of various packaging articles such as oriented films and bottles.