A Phosphorous-Containing Bio-Based Furfurylamine Type Benzoxazine and Its Application in Bisphenol-A Type Benzoxazine Resins: Preparation, Thermal Properties and Flammability

Abstract

Polybenzoxazine (PBa) composites based on phosphorous-containing bio-based furfurylamine type benzoxazines (D-fu) and bisphenol-A type benzoxazines (Ba) were developed for flame retardation. The structure of D-fu was analyzed by Fourier transform infrared (FTIR) spectroscopy and 1H-NMR spectroscopy. The curing temperature of Ba/D-fu mixtures was systematically studied by differential scanning calorimetry (DSC). Thermogravimetric analysis (TGA) demonstrated the excellent char formation ability of the PBa composites with the addition of phosphorous-containing D-fu. The flame retardancy of the PBa composite materials was tested by the limited oxygen index (LOI), vertical burning test (UL-94) and cone calorimeter (CONE). The LOI and UL-94 level of PBa/PD-fu-5% reached 34 and V0 rate, respectively. Notably, the incorporation of 5% D-fu into PBa led to a decrease of 21.9% at the peak of the heat-release rate and a mass-loss reduction of 8.0%. Moreover, the fire performance index increased, which demonstrated that the introduction of D-fu can diminish fire occurrence. The role of D-fu in the condensed and gas phases for the fire-resistant mechanism of the PBa matrix was supported by SEM-EDS and TGA/infrared spectrometry (TG-FTIR), respectively. Dynamic mechanical analysis (DMA) revealed that the Tg of PBa flame-retardant composites was around 230 °C. Therefore, PBa composites are promising fire-retardant polymers that can be applied as high-performance functional materials.

Phosphaphenanthrene-Functionalized Benzoxazines Bearing Intramolecularly Hydrogen-Bonded Phenolic Hydroxyl: Synthesis, Structural Characterization, Polymerization Mechanism, and Property Investigation

“…Unfortunately, no information related to structural characterization was provided in this study either . In addition, Zhao et al obtained two benzoxazine isomers rather than a single monomer based on ODOPB and furfurylamine in a recent study . All previous studies indicate the great challenge in synthesizing a pure compound using ODOPB as the starting phenolic resource in benzoxazine synthesis.…”

“…9,10-Dihydro-9-oxa-10-phosphaphenathrene-10-oxide (DOPO) and its derivative 10-(2,5-dihydroxyphenyl)-9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (ODOPB) (Scheme S1) are well-commercialized flame retardants, which can delay ignition and hinder flame propagation, thereby reducing fire risks of polymeric materials. − Several DOPO-containing benzoxazine resins have been designed and synthesized for the rich molecular design flexibility. − As shown in Scheme S1, ODOPB contains two phenolic hydroxyls. The one close to the phosphorous atom is expected to form an intramolecular hydrogen bond with the oxygen from PO or P–O, while the other can react with amine and formaldehyde to form an oxazine ring.…”

“…51 In addition, Zhao et al obtained two benzoxazine isomers rather than a single monomer based on ODOPB and furfurylamine in a recent study. 52 All previous studies indicate the great challenge in synthesizing a pure compound using ODOPB as the starting phenolic resource in benzoxazine synthesis. From the chemical structure of ODOPB, it might be true for the phenolic −OH at the ortho-position of the phosphorus atom, which can form a sixmembered ring via intramolecular hydrogen bonding with the oxygen atom in P�O or P−O group, hence reducing its capability in oxazine ring closure.…”

Beyond 2,5-furandicarboxylic acid: status quo, environmental assessment, and blind spots of furanic monomers for bio-based polymers

“…[195][196][197] In fact, some of these compounds were already considered as a new type of amine monomer for the production of polybenzoxazine (PBPB) resins and polyamides, despite the fact that the number of studies is still moderate when compared to FDCA-based polyamides, and particularly considering polyesters counterparts. 182,[198][199][200][201][202] Furfuryl amine-based PBs, synthetized trough benzoxazine monomers ring opening polymerization (ROP), is an emerging topic based upon Mannich condensation 203 approach used to synthesise benzoxazine monomers taking advantage from the versatility of the structural design capacity they offer. 198,203,204 Furthermore, these phenolic resins can have excellent thermal [198][199][200][201][202] and dielectric properties, low moisture absorption, low surface energy and flammability and corrosion resistance, 198,201,202 which makes them suitable for space, defence, and communication applications.…”

“…182,[198][199][200][201][202] Furfuryl amine-based PBs, synthetized trough benzoxazine monomers ring opening polymerization (ROP), is an emerging topic based upon Mannich condensation 203 approach used to synthesise benzoxazine monomers taking advantage from the versatility of the structural design capacity they offer. 198,203,204 Furthermore, these phenolic resins can have excellent thermal [198][199][200][201][202] and dielectric properties, low moisture absorption, low surface energy and flammability and corrosion resistance, 198,201,202 which makes them suitable for space, defence, and communication applications. 199,200,205 Table 12 summarizes some of the thermal features of previously reported PBs.…”