2.1. Synthesis of Polyesters

A series of high-molecular-weight poly(alkylene furanoate) and poly(alkylene terephthalate) samples were synthesized by applying melt polycondensation as described in our previous studies [23,24].

Dimethyl terephthalate (DMT) was obtained from Du Pont De Nemours Co (Hamm, Germany) and 2,5-furan dicarboxylic acid (purum 97%) was purchased from Sigma-Aldrich Chemical Co (Chemie GmbH, Hamburg, Germany). Tetrabutyl titanate (TBT) catalyst of analytical grade; 1,2-ethanediol, 1,3-propanediol, both of analytical grade; and 1,4-cyclohexanedimethanol (CHDM, 70/30 trans/cis, purum 99%), used as diols for polyester synthesis, were purchased from Sigma–Aldrich Chemical Co (Chemie GmbH). All other materials and solvents used were of analytical grade. Solid-state polycondensation (SSP) was subsequently applied to produce polymers of high molecular weight. The reaction path for the synthesis of the polyesters is shown in Figure 1.

Reaction path for the synthesis of poly(alkylene 2,5-furan dicarboxylate)s studied in this work.