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

Abstract

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 °C and 102 to 175 °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.

Unlocking the potential of furan-based poly(ester amide)s: an investigation of crystallization, molecular dynamics and degradation kinetics of novel poly(ester amide)s based on renewable poly(propylene furanoate)

“…In our case, only a single peak corresponding to the intermolecular hydrogen bonded N−H groups was found at 3295 cm -1 for all the produced materials. In combination with our recent work 29 , where a similar behavior was observed, these results suggest that introducing an aliphatic "spacer" between the furan ring and the amide bonds suppresses the intramolecular hydrogen bonding. This allows for to the desired intermolecular interactions between the polymer chains, vital for semi-crystalline PEAs.…”

“…The chemicals were used without further purification. N,N′-(butane 1,4diyl)bis(6-hydroxyhexanamide) (amido diol, AD) was synthesized as previously reported 29,34 .…”

“…We have recently demonstrated that long chain PEAs containing furan moieties can be obtained through traditional melt polycondensation 29 . Indeed, semicrystalline materials/polymers, that crystallized from the molten state, were produced starting from a preformed symmetric amido diol, 1,10-decanediol and DMFD.…”

“…Indeed, semicrystalline materials/polymers, that crystallized from the molten state, were produced starting from a preformed symmetric amido diol, 1,10-decanediol and DMFD. The introduction of the amide moieties increased the crystallinity of the materials, while also enhancing their thermal and mechanical properties 29 . The above mentioned side reactions occurring in traditional melt polycondensations were suppressed, while in parallel the use of solvents that are mandatory for enzymatic polymerization was completely avoided, granting a greener approach to the synthesis of furan-based PEAs.…”

“…Typical resonances of propanediol furanoate units are observed at 2.2, 4.5 and 7.2 ppm, while signals corresponding to the amido diol furanoate segments are also clearly visible. 29 The composition of the polymer regarding the two diols can be easily calculated based on the resonances at circa 4.3 and 4.5 ppm which correspond to the methylene groups adjacent to the ester moieties for AD and PD respectively. As we can observe in Table 1, the PDΟ percentage in the final copolymers is slightly lower than in the feed.…”