No 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.

Ιn this work novel polyester amides (PEAs) based on biobased poly(propylene furanoate) (PPF) were synthesized via traditional melt polycondensation, utilizing a preformed symmetric amido diol (AD) containing two internal amide...

Polymers from renewable feedstocks are receiving increasing attention as the awareness about environmental issues derived from petroleum exploitation and waste accumulation is growing. With unsaturated polyester resins being one of the most used classes of polymers worldwide, the utilization of biobased monomers for manufacturing is more relevant than ever. In the present work, succinic acid, one of the most promising biobased building blocks, was incorporated in the structure of the resins in question to increase their biobased content. By reacting with ethylene glycol (EG) or poly(ethylene glycol) and maleic anhydride (MA) at several molar rations, unsaturated polyester resins (UPRs) were prepared. Their synthesis was evaluated by a variety of spectroscopical techniques, and their rheological properties made use of the reactive diluent mandatory for facilitating processing. Thus, in a second stage acrylic acid (AA) was used as cross-linking agent in the present of initiators and accelerators producing thermosetting resins. Differential scanning calorimetry (DSC) was employed to screen the cross-linking procedure, whereas with X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy (FTIR) it was proven that thermosetting resins were prepared. The thermal stability of the cured materials was evaluated by thermogravimetric analysis (TGA).