Recyclable biobased materials based on Diels–Alder cycloaddition

Abstract

Poly(ethylene glycol) diglycidyl ether‐furfurylamine (PGFA) containing pendant furan was synthesized, and a series of crosslinked materials with thermally reversible capacity were synthesized through a furan/maleimide Diels–Alder (DA) reaction between PGFA and bismaleimide (BMI). The kinetics of the PGFA/BMI DA reaction were studied by Fourier transform infrared spectroscopy (FTIR). The reaction conversion rate, the reaction rate constant, and the energy of the DA reaction at different temperatures were calculated. In addition, the retro Diels–Alder (rDA) reaction was studied via 1H‐NMR, differential scanning calorimetry, and in situ FTIR. The occurrence of the retro DA reaction has been characterized clearly. Finally, the mechanical properties of the materials were obtained by dynamic mechanical and tensile tests. The storage modulus decreased obviously when the temperature reached over 90 °C, which proved that the materials were thermally reversible at high temperature. By changing the proportion of the crosslinking agent BMI, the best‐performing materials were obtained, and the properties of the materials were basically unchanged after recycling. Thus we have obtained an excellent reusable material. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47352.

Development of a completely recyclable glass fiber‐reinforced epoxy thermoset composite

“…Solvolysis experiments were previously performed by immersing samples of the different composites in different high boiling solvents, such as dimethylformamide (DMF), dimethylsulfoxide (DMSO), and propylene carbonate, upon raising the temperature to 120–125°C (reverse‐DA [r‐DA] range) the decross‐linked resins could be dissolved and black solids (mostly fibers) collected by hot filtration over a polytetrafluorethylene filter 19 ; however, the recollected fabric still contained between 5 and 37% resin leftovers. Similar to this study, cross‐linked polyurethanes 20 and Poly(ethylene glycol) diglycidyl ether‐furfurylamine 21 containing DA‐based cross‐links could be dissolved in hot DMF as well as comb‐shaped aromatic polyamide 22 and thermosetting polyketones 23 both cross‐linked by DA chemistry in hot N‐methylpyrrolidone and in hot DMSO, respectively.…”

The Use of Click-Type Reactions in the Preparation of Thermosets

“…It is worth mentioning that biobased materials, namely vegetable oils [183,184] or tannins [185] have been also prepared by D-A reaction.…”

Synthesis of Resins Using Epoxies and Humins as Building Blocks: A Mechanistic Study Based on In-Situ FT-IR and NMR Spectroscopies

“…A class of polymers that are widely used due to their variety of excellent properties including adhesion, mechanical performance, thermal resistance and chemical environmental stability are the epoxy resins. Nowadays, epoxy monomers can be obtained from plant oils or from other bio-based raw materials [7,8,9]. One of these examples is the glycerol diglycidyl ether (GDE), which is obtained from glycerol.…”