Partially bio‐based furyl‐functionalized organosoluble poly(ether ether ketone)s

Abstract A new series of partially bio‐based (co)poly(ether ether ketone)s bearing pendent furyl groups was synthesized by nucleophilic aromatic substitution polycondensation of varying molar proportions of 4,4′‐(furan‐2‐ylmethylene)bis(2‐methoxyphenol) and bisphenol‐A with 4,4′‐difluorobenzophenone. The chemical structures, compositions and random nature of (co)poly(ether ether ketone)s were confirmed by NMR spectroscopy. Inherent viscosities and number‐average molecular weights of the (co)poly(ether ether ketone)s were in the range 0.74–2.90 dL g −1 and 33 500–46 300 g mol −1 , respectively, indicating the formation of reasonably high molecular weight polymers. (Co)poly(ether ether ketone)s were readily soluble in common organic solvents and could be cast into tough, transparent and flexible films from chloroform solutions. (Co)poly(ether ether ketone)s exhibited 10% weight loss and glass transition temperatures in the range 429–464 and 152–156 °C, respectively. A representative copoly(ether ether ketone) was crosslinked with 1,1′‐(methylenedi‐1,4‐phenylene)bismaleimide via Diels–Alder reaction to form a crosslinked polymer which showed improved mechanical properties and was recycled twice without significant loss of mechanical properties. Diels–Alder/retro Diels–Alder reaction was demonstrated by studies of sol–gel transformation, solubility tests, DSC and stress–strain measurements. © 2020 Society of Chemical Industry