A naringenin-based benzoxazine with an intramolecular hydrogen bond as both a thermal latent polymerization additive and property modifier for epoxy resins

Abstract

<p>A naringenin-based benzoxazine containing a latent catalytic system was designed and successfully synthesized and it can be used as both a thermal latent polymerization additive and a beneficial property modifier for epoxy resins.</p>

Multifunctional Biobased Benzoxazines Blended with an Epoxy Resin for Tunable High-Performance Properties

“…Benzoxazine-epoxy resin formulations are one of the most academically and commercially relevant class of benzoxazine materials and are a topic of great interest in recent benzoxazine research. − Benzoxazine-epoxy (B-E) resin formulations have shown to increase the processability, cross-link density, and T g and enhance mechanical properties of the resulting polymer compared to the benzoxazine homopolymer. − B-E resins do not require the use of a curing agent as phenolic hydroxyl groups generated from the ring-opening of the benzoxazine are able to catalyze the ring-opening of oxirane rings in epoxy resins. , Furthermore, liquid epoxy resins can serve as reactive diluents for typically solid powder benzoxazines, which is advantageous for resin processing. − , B-E resins containing petroleum-derived bisphenol A and bisphenol-F have been reported, but a fully biobased benzoxazine monomer blended with a commercial epoxy resin has not been studied.…”

Chrysin-Based Bio-Benzoxazine: A Copolymerizable Green Additive for Lowering Curing Temperatures and Improving Thermal Properties of Various Thermosetting Resins

“…As shown in Figure , poly­(CHR-ac/BA-a) , poly­(CHR-ac/DGEBA) , and poly­(CHR-ac/DDM-BMI) show T g values of 221, 276, and 315 °C, respectively. Meanwhile, the T g values of poly­(BA-a), poly­(DDM/DGEBA) and poly­(DDM-BMI) have been reported as 162, 171, and 222 °C from previous studies. − Compared to poly­(BA-a), poly­(DDM/DGEBA), and poly­(DDM-BMI), T g values of thermosets based on resin blends have been increased by 59, 105, and 93 °C with the introduction of CHR-ac in each system (Figure ).…”

Recent development on bio‐based thermosetting resins

“…136 Moreover, some flavonoids could be designed as bio-based benzoxazine resin with intrinsic intramolecular hydrogen bonds, which were considered to have latent catalytic effect on the polymerization of benzoxazine, of which their molecules were illustrated in Scheme 13. 133,137,138 The carboxyl group in bisphenol acid can either play a role of the catalyst to promote ring-opening polymerization of benzoxazine resin or the modification reaction site. The latter one serves as the main chemical methods for functionalization, which will be discussed in next section.…”

“…Furthermore, the carbonyl group in deoxybenzoin is thought to isomerize to produce protons with catalysis effect in lowering the ring‐opening polymerization temperature 136 . Moreover, some flavonoids could be designed as bio‐based benzoxazine resin with intrinsic intramolecular hydrogen bonds, which were considered to have latent catalytic effect on the polymerization of benzoxazine, of which their molecules were illustrated in Scheme 13 133,137,138 …”