Biobased Diels‐Alder Engineered Network from Furfuryl Alcohol and Epoxy Resin: Preparation and Mechano‐Physical Characteristics

Abstract

This study reports the use of Diels-Alder (DA) chemistry to engineer a three-step strategy for making a novel hybrid epoxy-furan network (HDAN), from DGEBA resin and the fully bio-based monomer furfuryl alcohol (FA). Thus, a furfurylated epoxy resin-(FER) was synthesized via reaction of DGEBA and FA. FER was blended with poly(furfuryl alcohol) bio-resin, and in turn crosslinked with a bismaleimide to form HDAN. HDAN showed an inferior mechanical properties but superior thermostability compared to those of a control sample i.e. aminecured DGEBA. Degradability of HDAN network was investigated both by thermal and ultrasonic methods. The results proved that the ultrasonic degradation isan alternative method for the thermal retro-DA reaction. DSC and FTIR analysis confirmed the formation, disconnection and re-formation of DA cross-linkages. Excellent thermo-remending of scratched samples and practical welding of separated sample pieces were also approved by electron microscopy. In conclusion, HDAN was considered as an initiative candidate to be used in advanced applications (e. g., polymer composites…) requiring re-processability, re-mendability and weldability.

Self‐healing semi‐IPN materials from epoxy resin by solvent‐free furan–maleimide Diels–Alder polymerization

“…To the best of our knowledge, only one previous study has utilized DA reaction to prepare thermally reversible organic–inorganic IPN, and no semi‐IPN materials with thermoreversibility and self‐healing properties have been reported previously. In our earlier papers, we reported self‐healing DA networks by employing dimethylformamide (DMF) . It is a necessary solvent which has also been used in the majority of works in this field .…”

Recyclable biobased materials based on Diels–Alder cycloaddition

“…In addition, a number of thermally reversible healing materials and biological materials have been constructed based on this DA reaction . Modified epoxy resin was chosen by some researchers to construct DA reversible materials . Currently, most studies put emphasis on modifying the common epoxy monomer diglycidyl ether of bisphenol A (DGEBA) or changing the synthesis path to achieve epoxy healing materials, but ignore the improvement of the internal structure of epoxy materials.…”

Thermally Healable and Recyclable Graphene-Nanoplate/Epoxy Composites Via an In-Situ Diels-Alder Reaction on the Graphene-Nanoplate Surface

“…The opening reaction of the oxirane ring in DGEBA upon curing was confirmed by FT-IR spectroscopy, as shown in Figure S2. After curing, the peak intensity at 915 cm −1 due to the oxirane ring in DGEBA was substantially reduced by the reaction [5,10,12,15,16]. In Figure 3a, FA shows characteristic peaks at 1530–1570 and 1339 cm −1 due to double bonds and divinyl alkyl ether bonds, respectively.…”

“…Figure 3b shows the DSC thermograms of GEN-0.1-HD and GEN-0.1-HD. The endothermic peak at approximately 90–160 °C in GEN-0.1-D is attributable to the retro DA reaction [5,9,10,11,15,16,17]. Thus, it is postulated that the DA reaction occurred in the DGEBA systems but not in the HDE systems.…”

“…First, to introduce the DA reaction in the epoxy backbone, the synthesis of epoxy or amine-terminated DA adduct is needed to protect the double bond of dienophile [8,9,10]. Second, a furan-terminated backbone polymer is prepared and then reacted with bismaleimide as a crosslinker in a solvent or using extrusion [11,12,13,14,15,16,17]. If the dienophile could be replaced with a material other than maleic anhydride or maleimide, then epoxy composites could be prepared by the DA reaction using a simple process.…”