Synthesis and cross-linking behavior of biobased polyesters composed of bi(furfuryl alcohol)

Abstract

Furfuryl alcohol is a biobased chemical obtained from inedible biomass that could potentially become a viable alternative for petroleum-based chemicals. In this study, we have coupled furfuryl alcohol to bi(furfuryl alcohol) (BFA), which can act as a bifunctional monomer. A single-crystal X-ray diffraction analysis of BFA revealed that the bifuran moiety adopts a rigid structure due to the anti-parallel and co-planar geometry of the two π-conjugated furan rings. BFA was subsequently polymerized with succinic anhydride to poly(bifurfurylene succinate) (PBFS). The alpha relaxation temperature (Tα) and melting temperature (Tm) of bifuran-containing PBFS are higher than those of polyesters containing mono-furan rings. The cross-linking reaction of PBFS with bismaleimide afforded cross-linked PBFS, which exhibited increased Tα and mechanical strength due to the restriction in mobility that results from the formation of the cross-linking points. The 1H NMR spectra and SEC analysis revealed that the cross-linked PBFS was a ladder-type polymer.