Formaldehyde-Free Synthesis of Fully Bio-Based Multifunctional Bisbenzoxazine Resins from Natural Renewable Starting Materials

Macromolecules, Год журнала: 2022, Номер 55(8), С. 3106 - 3115

Опубликована: Апрель 6, 2022

Although bio-based benzoxazines (BZs) have been explored widely as sustainable thermosetting resins, few high-performance BZs prepared completely from natural renewable resources. In this study we synthesized a fully multifunctional bisbenzoxazine (AP-fa-BZ) in high yield and purity apigenin (AP), furfurylamine (fa), benzaldehyde by using both solvent solventless approaches. Fourier transform infrared (FTIR) spectroscopy, high-resolution mass spectrometry, one- two-dimensional nuclear magnetic resonance spectroscopy confirmed the chemical structure of AP-fa-BZ. We then used dynamic mechanical analysis, differential scanning calorimetry (DSC), thermogravimetric situ FTIR to examine thermal characteristics AP-fa-BZ before after its ring-opening polymerization (ROP). DSC revealed that temperature required for formation poly(AP-fa-BZ) through ROP (236.3 °C) was significantly lower than typical 4-phenyl-3,4-dihydro-2H-1,3-benzoxazine (Pa-type) monomer due positive catalytic effect phenolic OH groups AP structure. After at 250 °C, resulting possessed decomposition (Td10 = 395 °C), char (52 wt %), glass transition (Tg 283 °C). Contact angle measurements tunable surface properties Finally, resin functioned an antibacterial agent against Staphylococcus aureus Escherichia coli.

Язык: Английский

---

Biobased Vitrimers: Towards Sustainability and Circularity

Chemical Communications, Год журнала: 2025, Номер unknown

Опубликована: Янв. 1, 2025

Bio-based vitrimers represent a green and sustainable bridge between thermoplastics thermosets.

Язык: Английский

---

Lignin-based benzoxazines: A tunable key-precursor for the design of hydrophobic coatings, fire resistant materials and catalyst-free vitrimers

Chemical Engineering Journal, Год журнала: 2022, Номер 453, С. 139895 - 139895

Опубликована: Окт. 20, 2022

The meaningful concept of circular economy has prompted the scientific community to re-think design materials. In this work, lignin-based benzoxazines (LBZs) thermosets with tuneable properties were synthesized in agreement principles Green Chemistry, following a straightforward two-step synthetic route. reactivity soda lignin was enhanced by its esterification phloretic acid, naturally occurring phenolic acid. Thereafter, resulting structure enriched rings no ortho substituents, used prepare LBZs precursors bio-based primary amine via Mannich-like ring-closure reaction. and each LBZ precursor confirmed multiple NMR techniques, Fourier transform infrared spectroscopy, elemental analysis, gel permeation chromatography, differential scanning calorimetry, rheology, solubility assays. Lignin-based polybenzoxazine high mass fraction (between 46 66 wt.%) obtained curing vacuum compression molding manufacture process. exhibit single-phase X-ray computed tomography Tg ranging from 136 197 °C, storage moduli 0.5 3.1 GPa. features tuned depending on close oxazine ring. Stearylamine confers good processability yields hydrophobic coatings water contact angle reaching 91°. Furfurylamine-based generate high-Tg (197 °C) fire-resistant materials peak heat release rate no>47 W.g−1. Finally, ethanolamine produces capable internally catalysed bond exchange transesterification, providing vitrimeric such as fast stress relaxation (τ*200 °C = 233 s) complete circularity.

Язык: Английский

---

Biobased Polybenzoxazine Vitrimer with Imine Bonds: Shape Memory, Reprocessing, and Degradation

ACS Sustainable Chemistry & Engineering, Год журнала: 2024, Номер 12(20), С. 7739 - 7747

Опубликована: Май 9, 2024

A biobased reprocessable and degradable polybenzoxazine vitrimer was prepared by introducing dynamic imine bonds. An aldehyde-containing benzoxazine monomer (VSA) synthesized through the Mannich reaction of vanillin, stearylamine, paraformaldehyde, then VSA reacted with 1,12-dodecanediamine to prepare an imine-containing (VSA-dda). The curing behaviors VSA-dda were characterized in situ Fourier-transform infrared spectroscopy differential scanning calorimetry. exchange bonds within cross-linked network (PVSA-dda) studied stress relaxation experiments. Due presence bonds, PVSA-dda could be reprocessed hot-pressing at 140 °C under 2 MPa. exhibited a shape memory property recover its original heating 100 °C. degradation performance investigated various conditions, results showed that degraded 29 min acidic solution tetrahydrofuran water 50

Язык: Английский

---

High strength, self-healing and hydrophobic fully bio-based polybenzoxazine reinforced pine oleoresin-based vitrimer and its application in carbon fiber reinforced polymers

Chemical Engineering Journal, Год журнала: 2024, Номер 484, С. 149585 - 149585

Опубликована: Фев. 12, 2024

Язык: Английский

---

Preparation of Thermally Resistant and Mechanically Strong Biomass Benzoxazine Resins via Green Strategy

ACS Sustainable Chemistry & Engineering, Год журнала: 2024, Номер 12(3), С. 1247 - 1254

Опубликована: Янв. 10, 2024

Developing biomass resins with high thermal resistance and mechanical performance through a green strategy is an interesting challenge. Increasing the functionality of oxazine ring favorable to improve strength resins; however, no tri- or more functional benzoxazine monomers synthesized using have been reported. Herein, two novel trifunctional (coded as DPTA-f DPTR-f) very low melting points (61, 49 °C) were raw materials (diphenolic acid, tyramine, tyrosol, furfurylamine) solvents (ethanol water). The cured DPTR-f, designed P(DPTA-f) P(DPTR-f), not only exhibit storage moduli (3600 3080 MPa) tensile (65.0 55.1 but also glass transition temperature (Tg = 328, 302 initial degradation (351 350 °C), especially exhibits bigger Tg than all prepared (SCI database). They good flame retardancy. above excellent processing nature DPTR-f together competitive benefits from unique chemical aggregate state structures biobased benzoxazines.

Язык: Английский

---

Combination of Polyethylenimine and Vanillin-Based Benzoxazine as a Straightforward Self-Healable System with Excellent Film-Forming Ability

Macromolecules, Год журнала: 2024, Номер 57(5), С. 2078 - 2089

Опубликована: Фев. 24, 2024

This study introduces a straightforward and efficient route for synthesizing self-healable polybenzoxazine networks by utilizing dynamic imine bond exchanges under mild conditions. The process involves combining polyethylenimines with aldehyde-functional bisbenzoxazine, which was produced from vanillin, using Sc(OTf)3 catalyst subjecting them to moderate heating at 150 °C. Remarkably, the resulting films exhibit good self-healing capabilities low temperatures pressures, without requiring any additional additives facilitate healing process. degree of recovery assessed through tensile tests, while rheologic measurements were utilized analyze stress relaxation activation energy bonding, providing insights into Additionally, comprehensive spectral characterizations investigations thermal behaviors conducted gain deeper understanding material's properties performance. Moreover, demonstrated enhanced hydrolysis stability compared conventional imine-based systems, benefiting specific Mannich linkages inherent hydrophobic nature polybenzoxazines.

Язык: Английский

---

Deciphering the Self-Catalytic Mechanisms of Polymerization and Transesterification in Polybenzoxazine Vitrimers

Journal of the American Chemical Society, Год журнала: 2024, Номер 146(19), С. 13367 - 13376

Опубликована: Май 2, 2024

The use of internal catalysts has emerged as a pivotal design principle to facilitate dynamic exchanges within covalent adaptable networks (CANs). Polybenzoxazines, specifically, have shown considerable potential in generating vitrimers through thermally induced transesterification reactions catalyzed internally by tertiary amines. This study aims investigate the chemical complexities benzoxazine vitrimers. To achieve this, model molecules using various phenolic acids and amino-alcohol derivatives were synthesized precursors. structure these was fully elucidated nuclear magnetic resonance (NMR). Differential scanning calorimetry (DSC) rheology experiments evidenced accelerated network formation precursors due presence aliphatic −OH groups. Thermogravimetric analysis coupled with microcomputed gas chromatography (TGA-μGC) used provide evidence reactions. results showed that spatial proximity between amine hydroxyl groups significantly enhances rate exchange, attributed neighboring group participation (NGP) effect. Interestingly, kinetic complementary NMR techniques revealed thermal latency toward its opening is needed trigger exchange. highlights crucial role steric hindrance basicity promoting exchange an system.

Язык: Английский

---

Biobased Polybenzoxazine Containing Acetal Structures: Adhesion, Rebonding, and Degradation Properties

Polymer, Год журнала: 2025, Номер unknown, С. 128180 - 128180

Опубликована: Фев. 1, 2025

Язык: Английский

---

Bio-Based Vitrimers from 2,5-Furandicarboxylic Acid as Repairable, Reusable, and Recyclable Epoxy Systems

ACS Applied Polymer Materials, Год журнала: 2022, Номер 5(1), С. 828 - 838

Опубликована: Дек. 23, 2022

In this work, a series of bio-based epoxy vitrimers were developed by reacting diglycidyl ether bisphenol A (DGEBA) and 2,5-furandicarboxylic acid (FDCA) at different molar ratios. Triazabicyclodecene was used as transesterification catalyst to promote thermally induced exchange reactions. Differential scanning calorimetry, gel content measurements, Fourier transform infrared spectroscopy study the FDCA-DGEBA crosslinking reaction. The reaction kinetics such crosslinked systems characterized via stress relaxation tests, evidencing an Arrhenius-type dependence time on temperature, activation energy dynamic rearrangement depending composition. addition, self-healing, thermoformability, mechanical recycling demonstrated for composition showing faster topology rearrangement, namely, FDCA/DGEBA ratio equal 0.6. This work provides first example incorporating FDCA, making these primary importance in field reversible, high-performance materials future circular economy scenarios.

Язык: Английский

---