Poly(propylene naphthalate-co-propylene 2,5-furandicarboxylate)s derived from bio-based 2,5-furandicarboxylic acid (FDCA): Synthesis, characterization and thermo-mechanical properties

A series of poly (propylene naphthalate-co-propylene 2,5-furandicarboxylate)s (PPNFs) were synthesized by the melt polycondensation method from 2,5-furandicarboxylic acid (FDCA), 2,6-naphthalenedicarboxylic acid (2,6-NDCA) and 1,3-propanediol (1,3-PDO). Their composition and sequence distribution were analyzed by 1 H NMR and 13 C NMR. Crystallization behaviors , thermal and mechanical properties were investigated. The weight-average molecular weights of PPN, PPF and PPNFs were higher than 28 000 g mol −1 and the polydispersity index was between 2.1 and 2.7. DSC and XRD results show that poly (propylene 2,5-furandicarboxylate) (PPF) and poly (propylene naphthalate) (PPN) are semi-crystalline polymers, but all PPNFs are amorphous polymers. With increasing the content of FDCA, the initial temperature of α-relaxation rose significantly. When the content of FDCA was 74 mol%, PPNF74 exhibited the high bio-based content (77.6 wt%) and good mechanical properties ( σ m  = 71 MPa and ε b  = 146%).