Synthesis and Ring-Opening Polymerization of Cyclic Butylene 2,5-Furandicarboxylate

A new synthetic pathway for the polymerization of furan based polyesters is reported in this work. First, poly(butylene 2,5-furandicarboxylate) cyclic oligoesters (COEs) are chemically synthesized by semi-batch esterification. The structure of the COEs is confirmed by infrared spectroscopy, 1H, and 13C-NMR, while the molecular weight distribution of the COEs is determined by matrix-assisted laser desorption/ionization time of flight mass spectroscopy. The cyclic oligoesters are then successfully polymerized via ring-opening polymerization using tetrakis(2-ethylhexyl)-titanate as catalyst. Differential scanning calorimetry and 1H-NMR analysis unambiguously proves the formation of polymeric species. Both end-group analysis from 1H-NMR spectrum and calculation through Flory-Fox equation give comparable estimates of the number average molecular weight: 5.8 × 103 g mol-1 and 7.8 × 103 g mol-1, respectively. Furanic polyesters, derived from renewable 2,5-furandicarboxylic acid, are highly attractive polymers and sustainable substitutes of some performance-related fossil-based commodities like polyethylene terephthalate. In this work a new synthetic pathway for the production of furan-based polyesters is reported. Cyclic oligoesters of 2,5-furandicarboxylic acid and butane diol are chemically synthesized by semi-batch esterification. The cycles are then successfully polymerized via ring-opening polymerization.