High‐Performance Bio‐Based Benzoxazines from Enzymatic Synthesis of Diphenols

Abstract

This paper reports the preparation, characterization, and performance of three low viscosity fully bio‐based benzoxazine resins synthesized from bio‐based furfurylamine, paraformaldehyde, and three new enzymatic originated diphenols obtained through a sustainable and highly selective lipase‐catalyzed enzymatic process from p‐coumaric acid, and three bio‐based diols (propanediol, butanediol, and isosorbide, respectively). The enzymatic method is used for the first time, to the authors’ knowledge, to design specific diphenolic structures dedicated to the preparation of benzoxazine thermosetting resins whose precursors exhibit easy handling within a wide processing window (from room temperature up to 200 °C). The resulting cross‐linked materials present high glass transition temperature (T g > 200 °C) and inherent charring ability upon pyrolysis (≈50 wt% at 1000 °C). These results open a valuable and new pathway to develop enhanced benzoxazines and bring them new properties.

Synthesis and properties of a novel bio‐based benzoxazine resin with excellent low‐temperature curing ability

“…With the extreme consumption of fossil energy, energy crises and environmental problems have become an issue that cannot be avoided and must be addressed positively. Therefore, the use of renewable bio‐based compounds instead of traditional fossil‐based compounds to prepare polymer materials has attracted many researchers . Benzoxazine monomer is prepared through dehydration to a ring by a Mannich condensation reaction based on a phenol source, an amine source and a formaldehyde solution or paraformaldehyde.…”

“…Therefore, the use of renewable bio-based compounds instead of traditional fossil-based compounds to prepare polymer materials has attracted many researchers. [1][2][3][4][5][6][7][8] Benzoxazine monomer is prepared through dehydration to a ring by a Mannich condensation reaction based on a phenol source, an amine source and a formaldehyde solution or paraformaldehyde. Benzoxazine resin is a kind of phenolic resin; furthermore it has better heat resistance, dielectric properties, low surface energy, low water absorption and no release of small molecules during processing compared with traditional phenolic resin, in addition to zero shrinkage and structure design flexibility.…”

Cerium Salts: An Efficient Curing Catalyst for Benzoxazine Based Coatings

“…More specifically, the FT-IR spectrum of 4EP-pPDA shows absorption peaks at 1516, 1223, 1034, and 945 cm −1 . Based on similar benzoxazine derivatives reported in the literature [43][44][45], they are ascribed to the trisubstituted benzene ring stretching, asymmetric stretching vibration of C-O-C, symmetric stretching vibration of C-O-C, and out-of-plane C-H, respectively. In the 1 H-NMR spectrum of 4EP-pPDA, the characteristic protons appear at around 4.51 (Ar-CH 2 -N) and 5.24 (O-CH 2 -N) ppm, confirming the formation of the 4EP-pPDA molecular structure [45][46][47].…”

Bioinspired Design Provides High‐Strength Benzoxazine Structural Adhesives

“…[11] This unique pool of potential starting materials includes arange of phenolic molecules that are just beginning to be explored as building blocks for 1,3benzoxazine monomers. [12] Nature not only provides access to constituents with useful chemical handles for materials synthesis,b ut also delivers inspiration for synthetic polymers and engineering materials with extraordinary properties and behaviors. [13] In our material design, we take inspiration from marine mussels, which have the ability to adhere strongly to aw ide range of substrates by secretion of threads terminated by adhesive plaques (the byssus).…”

“…Furthermore, the development of high throughput genomic engineering tools that integrate automation, machine learning, and molecular biology may enable cost‐effective and industrial‐scale access to the molecular diversity present in living systems . This unique pool of potential starting materials includes a range of phenolic molecules that are just beginning to be explored as building blocks for 1,3‐benzoxazine monomers …”