Thermo-reversible Diels–Alder polymerization of difurfurylidene trehalose and bismaleimides

Difurfurylidene trehalose (DFTreh) was synthesized by the reaction of trehalose and furfural, both of which are renewable resources. Diels–Alder polymerization of DFTreh with 4,4′-bismaleimidodiphenylmethane (BMIDP) or 1,6-bismaleimidohexane (BMIH) at 40–70 °C in DMF afforded novel trehalose-based linear polymer with Mw of ca. 15,000 in good yield. The retro Diels–Alder degradation of the obtained polymers in DMF rapidly progressed at ca. 140 °C to afford the corresponding monomers quantitatively, as is obvious from the GPC analysis. In case of DFTreh/BMIDP, the prolonged maintenance of the degraded mixture at 140 °C resulted in the homo-polymerization of the formed BMIDP.