High Glass Transition Materials from Sustainable Epoxy Resins with Potential Applications in the Aerospace and Space Sectors

Abstract

High glass transitions, high storage moduli, high thermal stability, and low water absorption values are crucial criteria of high-performant materials, though there is a challenge when we are confronting the bio-resourced materials with their performances. This work proposes the chemical combination of aromatic bio-based epoxy monomers with potential bio-based anhydrides to produce thermosetting materials with competitive performances. Triglycidyl ether of phloroglucinol (TGPh) and diglycidyl ether of vanillyl alcohol (DGEVA) were copolymerized with hexahydro-4-methylphthalic anhydride or methyl nadic anhydride. These copolymerization reactions start at low temperature, from 35 or 70 °C; that is a first advantage for an industrial up-scaling. The produced thermosets have high bio-based carbon content, ∼50–60%, high glass transition values (>100 °C for DGEVA-based resins and >200 °C for TGPh resins), high storage moduli (2.7–3.1 GPa at 30 °C), high thermal stability (T 5% = 329–359 °C), and very low water absorption (in average ∼1.5% after 15 days). These performances of these bio-based thermosets open windows of application in space, aerospace, or naval industry.

Enriching an Exchangeable Network with One of Its Components: The Key to High-Tg Epoxy Vitrimers with Accelerated Relaxation

“…As for the eco-conception of a future material, the presence of bisphenol A fragments may be questioned, even though DGEBA-based epoxy formulations are still the most used and food-approved . To comply with possible restrictions of use, the process to synthesize a tetrafunctional alcohol and the concept of shifting the transesterification equilibrium presented here can be applied to any polyepoxide, including biobased epoxy resins. − For instance, the diglycidyl ether of divanillyl alcohol (DiGEDVA) might be easily blended with its divanillyl alcohol precursor to reach the same goal as described here.…”

Development of Sustainable High Performance Epoxy Thermosets for Aerospace and Space Applications

“…The synthesized thermosets show high performances, as E modulus ~3 GPa, glass transition values ~96-108 • C for DGEVA based thermosets and 190-210 • C for TGPh based ones together with a low hydrophilicity, a high gel content ~99.9%, high thermal stability, etc. [11].…”

“…The tris(4hydroxyphenyl)methane triglycidyl ether (THPMTGE) was selected as a monomer as it is commercialized at industrial scale and its synthesis could be done from biobased synthons (condensation of phenol with benzaldehyde followed by glycidylation), [12][13][14][15][16][17]. In addition, in comparison with the previous work [11], the THPMTGE monomer has the advantage of containing a tri-aromatic core, differing from DGEVA and TGPh, which have mono-aromatic cores.…”

A vanillin derivative P/N/S‐containing high‐efficiency flame retardant for epoxy resin

“…This leads to its widespread use in molding compounds, microelectronic materials, coatings, and other applications. [1][2][3][4][5] Unfortunately, the flammability of general epoxy resin products limits its further application in areas where flame retardancy is required, especially in aerospace, electronics, construction, and so forth. 6 Therefore, halogen-containing flame retardants were commonly used to enhance the flame retardancy of epoxy resins.…”

“…Epoxy resin (EP) is a thermosetting resin with superior chemical and solvent resistance, good electrical insulation and dimensional stability, and favorable mechanical processability. This leads to its widespread use in molding compounds, microelectronic materials, coatings, and other applications 1–5 . Unfortunately, the flammability of general epoxy resin products limits its further application in areas where flame retardancy is required, especially in aerospace, electronics, construction, and so forth 6 .…”