High-performance hybrid materials prepared by the thermo-reversible Diels–Alder polymerization of furfuryl ester-terminated butylene succinate oligomers and maleimide compounds

Abstract

A furfuryl ester-terminated butylene succinate oligomer (FBSO) with Mn 1800 and Mw 2800 was synthesized by the condensation of furfuryl alcohol with a carboxyl-terminated butylene succinate oligomer. The reaction of FBSO and 1,1′-(methylenedi-4,1-phenylene)bismaleimide (BMI) in chloroform at 60 °C for 48 h yielded an exo-rich Diels–Alder (DA) adduct ((P(FBSO-BMI)) with Mn 9000 and Mw 15 500. The gel permeation chromatography analysis of the products of heating a reaction mixture of P(FBSO-BMI) in dimethylformamide (DMF) at 120 °C for 1 h revealed that FBSO and BMI are quantitatively recovered by the retro DA reaction. Maleimide/phenyl-substituted oligomeric silsesquioxane (MPOSS) was synthesized by the reaction of maleimidemethyl 3-(triethoxysilyl)propylcarbamate and triethoxyphenylsilane in the presence of hydrochloric acid. The DA reaction of FBSO and MPOSS in DMF at 60 °C for 48 h gave a partially crosslinked hybrid composite insoluble in general organic solvents. When the hybrid composite was heated in DMF at 140 °C, the retro DA reaction proceeded smoothly. The hybrid film prepared by casting a DMF solution of FBSO and MPOSS and subsequently heating at 60 °C for 48 h had a much higher flexural strength than FBSO did. The Diels–Alder (DA) reaction of furfuryl ester-terminated butylene succinate oligomer (FBSO) with 1,1′-(methylenedi-4,1-phenylene)bismaleimide (BMI) at 60 °C afforded a polyesterimide ((P(FBSO-BMI)). The gel permeation chromatography (GPC) analysis of the reaction mixture of P(FBSO-BMI) at 120 °C revealed that FBSO and BMI are quantitatively recovered by the retro DA reaction. When maleimide/phenyl-substituted oligomeric silsesquioxane (MPOSS) was used instead of BMI, a partially crosslinked thermo-reversible hybrid composite (P(FBSO-MPOSS)) was obtained. The hybrid film prepared by solvent casting method of FBSO and MPOSS had much higher flexural strength than FBSO did.