Efficient Toughening of DGEBA with a Bio-Based Protocatechuic Acid Derivative

Abstract

In this work, a bio-based epoxy resin, protocatechuic acid diester epoxy resin, (PDEP), was synthesized using protocatechuic acid. The structure and properties of PDEP have been characterized by 1 H NMR, 13 C NMR, and Fourier transform infrared. After different contents of PDEP were added to diglycidyl ether of bisphenol A (DGEBA), the modified epoxy resins were cured by 4,4′-diaminodiphenylmethane (DDM). With the addition of a flexible long-chain bio-based monomer to improve toughness, the impact strength was 50 kJ•m −2 with only 5.0 wt % PDEP; compared with pure DGEBA, the impact strength was 27 kJ•m −2 . Further, an increase in T g should be confirmed from the mechanical cross-linking density and rigidity group content. The single T g proved the homogeneous phase structure of the PDEP-cured resin. Morphology exhibiting the ductile fracture of the cured resin was confirmed by scanning electron microscopy. Overall, this work demonstrates the utilization of renewable protocatechuic acid as an effective modifier for epoxy resin, which reflects its potential application.

Development of fluorescent epoxy composite with carbon‐based nanomaterial additives derived from agricultural waste

“…This shifting of the peak is due to the interaction between the nanomaterial and the epoxy material. Also, the broad band observed in K‐GO at 3210 cm −1 and in the K‐GO/epoxy composite at 3380 cm −1 corresponded to the ‐OH groups, indicating the nanomaterials with the polymer matrix 35 . Because of this, the dispersion of the K‐GO was much better in the epoxy matrix.…”

“…Also, the broad band observed in K-GO at 3210 cm À1 and in the K-GO/epoxy composite at 3380 cm À1 corresponded to the -OH groups, indicating the nanomaterials with the polymer matrix. 35 Because of this, the dispersion of the K-GO was much better in the epoxy matrix. This has also been supported well by SEM analysis as shown earlier.…”