A Facile Method to Synthesize Semicrystalline Poly(ester amide)s from 2,5-Furandicarboxylic Acid, 1,10-Decanediol, and Crystallizable Amido Diols

The synthesis of polyamides and poly(ester amide)s derived from 2,5-furandicarboxylic acid frequently leads to amorphous polymeric materials. Formation of intramolecular hydrogen bonds between the oxygen heteroatom in the furan ring and hydrogens of the amide bonds reduces the intermolecular hydrogen bonds that are usually responsible for the high thermal and mechanical performance of these materials. To circumvent this problem, aliphatic-aromatic poly(ester amide)s were synthesized in this study from dimethyl 2,5-furandicarboxylate, 1,10-decanediol, and a preformed aliphatic diol containing two internal amide bonds (amido diol). Wide-angle X-ray diffraction and differential scanning calorimetry experiments revealed that polymers obtained were semicrystalline over the whole composition range and crystallized rapidly from the molten state, indicating that intramolecular H-bonding is effectively suppressed. Depending on the ratio of 1,10-decanediol and amido diol, the thermal properties could be adjusted over a wide temperature range. The polymers exhibit T-g and T-m in a range of -4 to 27 degrees C and 102 to 175 degrees C, respectively. Elastic modulus and hardness increased almost linearly with the amount of ester-amide moieties. The method presented herein allows for the successful synthesis of semicrystalline poly(ester amide)s from 2,5-furandicarboxylic acid without undesired intramolecular hydrogen bonds. This finding could set the stage for further bio-based poly(ester amide)s from 2,5-furandicarboxylic acid suitable for high-performance applications.