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[Display omitted] Iodocyclization of N -(2-alkenylphenyl)carboxamides with acetoxybenziodoxolone/NaI system gives 4-iodomethyl- 4 H -3,1-benzoxazines with high efficiency. The process is triggered by the oxidation of NaI with acetoxybenziodo- xolone to afford iodine cation which is added to alkene moiety to form iodonium species, and the ultimate intra- molecular nucleophilic addition generates the final products. [ABSTRACT FROM AUTHOR]

High-temperature curing is a major limitation for the widespread use of benzoxazine resins. This study explores two strategies to reduce curing temperatures using minimal sulfur content (1–5 wt%): ziram catalysis and light activation. Both approaches effectively promoted curing at lower temperatures compared to traditional methods. The ziram-activated system achieved an activation energy as low as 83 kJ/mol, while the UV-activated system reached 63 kJ/mol. Furthermore, the UV-activated sulfur system exhibited improved thermal stability, particularly for cresol-based benzoxazines. The curing processes of monomers with catalysts were traced using various techniques, including nuclear magnetic resonance (NMR), Fourier-transform infrared (FT-IR), along with differential scanning calorimetry (DSC). [Display omitted] • Elemental sulfur effectively lowers the ring-opening polymerization (ROP) temperature of benzoxazines. • To reduce sulfur content to 1-5 wt%, catalysts like ziram or UV light were used for activation. • These methods generate sulfur radicals or thiols, enabling benzoxazine curing at lower temperatures. [ABSTRACT FROM AUTHOR]

Benzoxazine is a newly developed thermoset resin that has attracted significant academic and industrial interest due to its excellent properties. However, improving its dielectric performance while maintaining high heat resistant is crucial for expanding its application in 5G electronics. In this study, we designed and synthesized a novel benzoxazine monomer, DFDA-PTB, using p - tert -butylphenol (PTB) as the phenol source and furfuryl diamine (DFDA), derived from furfuryl amine, as the amine source. Two additional benzoxazines with similar structures were also synthesized for comparison. The cured product, poly(DFDA-PTB), was then analyzed to explore the relationship between its structure and properties. The results indicate that the introduction of a furan ring structure enhances thermal stability and reduces the dielectric constant. Additionally, the inclusion of tert -butyl groups further lowers the dielectric constant and dielectric loss. Simulation methods were employed to study the mechanisms behind these improvements. Poly(DFDA-PTB) demonstrated superior dielectric properties, with a dielectric constant of 2.51 and a dielectric loss of 0.0018 at 10 GHz. It also exhibited excellent heat resistance, with a char yield of 45.4 % at 800 °C. These properties make poly(DFDA-PTB) a promising candidate for electronic packaging and communication applications. [Display omitted] • A novel benzoxazine was synthesized from furan diamine and p - tert -butylphenol. • The benzoxazine shows excellent heat resistance and low dielectric properties at high frequencies. • The impact of tert -butyl and furan rings on structure and performance was analyzed. [ABSTRACT FROM AUTHOR]

The inherent hydrophilicity and biocompatibility of cotton fabrics facilitated bacterial proliferation and safety concerns, limiting their applications. To address these issues, tyrosine-derived polyetherimide, bis(3-aminopropyl)-terminated poly(dimethylsiloxane), and paraformaldehyde were used to synthesize hyperbranched benzoxazine THB-BOZs-PDMS with potent antibacterial and antibiofilm activity. The protonated amino groups of benzoxazine facilitated electrostatic interactions with negatively charged bacteria, and hydrophobic interactions disrupted the cell membrane, leading to bacteria death. Notably, phytic acid interacts with benzoxazines through intermolecular forces, with its phosphoric acid groups facilitating the curing of benzoxazines, thereby imparting flame-retardant properties to the material. Consequently, a multifunctional coating was developed via LBL self-assembly and in-situ curing of benzoxazines and phytic acid on the fabric surfaces. The successful deposition of the coating was confirmed through compositional analysis and morphological characterization. After 4 cycles of LBL modification, the fabrics TBP + PA-CF-4 displayed outstanding antibacterial efficacy, bacterial anti-adhesion properties, and heat resistance. Furthermore, TBP + PA-CF-4 exhibited notable washing and mechanical durability, attributed to the stability conferred by in-situ cured of layers. Compared with other reported modified fabrics, TBP + PA-CF-4 displayed more comprehensive overall performances. These multifunctional fabrics provided a sustainable approach for advancing personal protective materials and public decoration, particularly suited for use in high-humidity environments or military settings. • Multifunctional fabric coatings based on phytic acid and polybenzoxazine were designed. • The coatings were prepared with the LBL self-assembly process and in situ curing. • Tyrosine-based benzoxazine THB-BOZs-PDMS with antibacterial activity were synthesized. • 4 times the number of layers endowed fabrics with outstanding comprehensive properties. [ABSTRACT FROM AUTHOR]

• Two novel 1,4-benzoxazine derivatives synthesized, showcasing distinct π···π, CH···π, and NH···O hydrogen bonding interactions. • Hirshfeld surface analysis and QTAIM/NCI plots delineate the intermolecular interactions. • DFT studies at the PBE0-D3/def2-TZVP level provide insights into the energy landscapes of π-stacking and hydrogen bonding. The synthesis and XRD characterization of two new 1,4-benzoxazine derivatives (3a - 5a) namely ethyl‐6‐nitro‐3a‐(p ‐tolylamino)‐1,2,3,3a‐tetrahydrobenzo[ b ]cyclopenta[e][1,4]oxa-zine‐9a(9 H)‐carboxylate (3a) and methyl-6,10b-dimethyl-5a,6,10b,11-tetrahydrobenzo[ 5 , 6 ][1,4]oxazino[2,3-b]indole-2-carboxylate (5a) are reported herein. In both compounds it is observed the formation of π···π and CH···π interactions and strong NH···O H-bonds, which were studied energetically at the PBE0-D3/def2-TZVP level of theory. The Hisrhfeld surface and QTAIM analyses and NCI plots were used to study the nature and the extent of different intermolecular interactions observed in both structures, revealing the existence of additional R 2 1 (6) and R 2 1 (7) synthons. In addition, using the potential energy density as energy predictor, the QTAIM method is useful to investigate the relative contribution of each interaction to the formation of the assemblies. Synthesis and XRD characterization of two new 1,4-benzoxazine derivatives are reported herein along with Hisrhfeld surface and QTAIM analyses and NCI plots to interpret the intermolecular interactions observed in the solid state. [Display omitted] [ABSTRACT FROM AUTHOR]

[Display omitted] • A full bio-based benzoxazine monomer and trifunctional benzoxazine phosphate ester (TBP) were synthesized. • As a curing agent, TBP significantly enhances the thermal and flame retardant performance of epoxy resin. • Under the synergistic effect of P-N in TBP, the flame retardant of the polymer is realized. • Under alkaline conditions, complete degradation of polymers can be achieved by ammonolysis. Most epoxy resins on the market have low thermal stability and flammable defects. As a potential curing agent for epoxy resin, polybenzoxazine (PBz) can effectively improve the thermal properties of the resin due to its low heat release capacity (HRC) and rigid aromatic ring support, and its raw materials can be derived from renewable resources. Here, we have successfully developed a molecular design strategy to obtain a trifunctional benzoxazine monomer with phosphate ester. Firstly, guaiacol-ethanolamine benzoxazine monomer (GE) was synthesized by Mannich condensation using guaiacol and ethanolamine as raw materials. Then trifunctional benzoxazine phosphate ester (TBP) was synthesized by the nucleophilic reaction of GE with phosphorus oxychloride. Finally, the epoxy resin DGEBA was cured by TBP to obtain a PBz modified epoxy resin (EP-TBP polymer) with T g of 113.7 °C and char yield of 37.4 %. Due to the introduction of TBP rich in phosphorus and nitrogen, it releases phosphorus radicals and nitrogen-containing inert gases during combustion, which leads to quenching effect and dilution effect. In addition, TBP can also promote the dehydration and dehydrogenation of the polymer and accelerate the formation of the aromatic hybrid char layer. Therefore, the THR of TBP modified epoxy resin is 49.3 % lower than that of epoxy resin without TBP, and the char yield is 47 times higher. And when the phosphorus content is 1.76 %, the flame-retardant grade can reach V-0. In addition, the introduction of TBP also enhanced the mechanical properties, adhesion properties and hydrophobicity properties of the polymer. It is worth mentioning that under alkaline conditions, the phosphate ester in the structure of EP-TBP polymer will undergo ammonolysis reaction with ethanolamine, and the resulting oligomers will be dissolved in it, thereby achieving rapid degradation of EP-TBP polymer. This work is to develop a high-performance multifunctional epoxy resin flame retardant curing agent based on renewable raw materials, and provide important insights for the subsequent development of halogen-free bio-based PBz flame retardant materials. [ABSTRACT FROM AUTHOR]

New type of diallyl bisphenol-A (ABA) based benzoxazines and benzoxazine resins tailored with epoxy groups for low-temperature curing, have been developed using various curatives for high performance applications. The molecular structure of the synthesized compounds was analyzed using HRMS, 1H NMR, 13C NMR and ATR-FTIR analytical techniques. The cure behavior (T p) of benzoxazine (Bz) and benz-epoxy (Bz-Ep) resin in the absence and presence of different nature of curatives were studied using DSC to evaluate their applicability for advanced composite applications. The values of T p obtained are 279 °C, 190 °C and 247 °C for ABA-a, ABA-dmapa and ABA-ipa respectively. The cure behavior has been further lowered by converting ally group present in the benzoxazine has been transformed into epoxy groups by appropriate mechanism. The curing (T p) temperature observed for hybrid ABA-a-Ep, ABA-dmapa-Ep and ABA-ipa-Ep benz-epoxy resins are 151 °C, 226 °C and 160 °C, 187 °C and 150 °C, 211 °C respectively. The T p of different benz-epoxy resin systems studied in the presence of catalysts were found to be in the range of 101-155 °C. With a T max of 484 °C and a char yield of 43 %, poly(ABA-a) exhibits impressive thermal stability when compared to other synthesized polybenzoxazines. Further, incorporating various curatives into the benz-epoxy matrix enhances its thermal stability and char yield compared to the neat matrices. Additionally, the developed samples exhibit excellent moisture resistant (0.75 %) and hydrophobic nature with the highest contact angle value of 152o for poly(ABA-a). The findings from various studies indicate that the hybrid benz-epoxy resins demonstrate characteristics such as low-temperature curability, thermal stability, hydrophobicity. These results render them appropriate for a diverse array of high-performance industrial and engineering uses. [Display omitted] • Diallyl bisphenol-A (ABA) based benzoxazines and benzoxazine-epoxy resins were synthesized. • In absence of catalyst diallyl bisphenol-A-dmapa-Ep cures at 160 °C and 187 °C. • In presence of oxalyldihydrazide catalyst diallyl bisphenol-A-dmapa-Ep cures at 101 °C and 155 °C. • Poly(ABA-a) in absence and presence of catalyst (dicy-urea) exhibit higher CY value. • Poly(ABA-benzoxazines) showed better hydrophobic nature than respective polybenz-epoxies. [ABSTRACT FROM AUTHOR]

Cellulose, as a biomass resource, has attracted increasingly attention and extensive research by virtue of its widely sources, ideal degradability, good mechanical properties and easy modification due to its rich hydroxyl groups. Nevertheless, it is still a challenge to attain high performance cellulose-based composite film materials with diverse functional combinations. In this work, we developed a multifunctional cellulose-based film via a facile impregnation-curing strategy. Here, benzoxazine resin (BR) is used as an optically functional component to endow the microfibrillated cellulose (MFC) film with powerful light management capabilities including UV and blue light double shielding, high transmittance, and high haze. Meanwhile, the introduction of tannic acid (TA) substantially enhanced the mechanical properties of the film, including tensile strength and toughness, by constructing energy-sacrificial bonds. An effective self-healing of the film was achieved by controlling the degree of BR curing. The final films exhibited 98.24 % UV shielding and 89.98 % blue light blocking, good mechanical properties including a tensile strength of 202.21 MPa and tensile strain of 7.1 %, as well as desirable thermal healing properties supported by incompletely cured BR. This work may provide new insights into the high-value utilization of biomass resources. [ABSTRACT FROM AUTHOR]

Cellulose is widely used as a biomaterial because of its good biodegradability and biocompatibility. In this study, the periodate oxidation method was used to prepare dialdehyde cellulose (DAC), which was then modified with polyamidoamine dendrimer (PAMAM G0) by the hyperbranched crosslinking synthesis to obtain novel dialdehyde cellulose-based polymers (DPs) with high thermal stability and antibacterial activity. The characterization found that PAMAM was successfully grafted onto the cellulose backbone. Moreover, the thermal weight-loss temperature of DPs decreased, the char yields increased, and the crystallinity decreased significantly as the amount of PAMAM increased. The crystallinity was about 46.50%. Specifically, when the ratio of the aldehyde group in DAC to the amine group in PAMAM was 1:1, the maximum thermal-denaturation temperature and weight-loss temperature (T max) of the DPs reached 136 ℃ and 365.8 ℃, respectively. In addition, DPs showed a uniform long-strip structure with a good particle size distribution, preventing the self-assembly and aggregation of cellulose and DAC. Disk diffusion tests showed that the DPs had significant antibacterial activity against Escherichia coli and Staphylococcus aureus, with the inhibition zone diameters reaching 13–15 mm. Thus, DPs with good thermal stability and antibacterial activity could be used as a new type of cellulose-based functional material. [Display omitted] • Cellulose-based functional material was first prepared by oxidizing and grafting. • Hyperbranched cellulose with a large amount of reactive amino group was obtained. • Polyamidoamine dendrimer improved thermal stability, and homogeneity of cellulose. • Modified cellulose had excellent antibacterial activity against E. coli and S. aureus. [ABSTRACT FROM AUTHOR]

• New kind of furfural core bis-thymol has been synthesized. • Different nature of fluorine substituted furfural-bis-thymol based benzoxazine have been synthesized. • Poly(FBT-pfsa) exhibited superhydrophobic behaviour of water contact angle value of 151°. • The developed material resulted excellent corrosion resistance towards mild steel specimen with 99 % efficiency. • The developed benzoxazines exhibited aggregated induced emission properties. Sustainable bis-thymol based benzoxazines have been synthesized using furfural bis-thymol (FBT) and paraformaldehyde separately with five different fluorine substituted amines through Mannich condensation process. The molecular structure of the obtained benzoxazines has been verified using spectroscopic analyses. The curing temperature of the synthesized benzoxazines are ranged between 241 °C and 277 °C. Among the synthesized polybenzoxazines, poly(FBT-pfa) exhibits the highest thermal stability of 52 % char yield. All the polybenzoxazines exhibit the value of LOI above the threshold limit of 26 which infers the self-extinguishing property of the polymer. Poly(FBT-pfsa) showed the highest value of water contact angle of 151°, which ascertains that the increased fluorine content contributes to the superhydrophobic nature. Results from hydrophobic durability studies with poly(FBT-pfsa) using coated cotton fabric under acidic and basic conditions indicate its suitability for hydrophobic applications. The corrosion protection ability of polybenzoxazines towards mild steel surfaces was studied and the results obtained suggest that these polybenzoxazines can be used as an excellent coating material. UV–Visible and fluorescence spectroscopic analyses infer that these benzoxazines exhibit aggregation induced emission (AIE) characteristics. Data from different studies suggest that these materials can be conveniently utilized in the form of optical, superhydrophobic and corrosion-resistant coatings. Bis-thymol based benzoxazines have been developed using sustainable furfural and thymol to study the superhydrophobic and anti-corrosive coating applications. Optical behavior also explored for photoluminescence applications. [Display omitted] [ABSTRACT FROM AUTHOR]

• A series of benzoxazine/benzothiazine appended 1,2,3-triazole hybrids were synthesized. • Synergic biological potential of benzoxazine/benzothiazine and 1,2,3-triazole moiety have been explored in this present work. • Most of the synthesized hybrids displayed moderate to good antimicrobial activity. • Docking simulation of potent 1,2,3-triazole hybrid 4r have been examined against antibacterial target. • In silico ADME studies of synthesized hybrids revealed that these compounds can be developed as potential oral drug candidates. In the present context to rationalize the search for new effective antimicrobial agents against the infections caused by microbes, a series of benzoxazine/benzothiazine appended 1,2,3-triazole hybrids were designed and synthesized via click reaction with ingredients of two or more bioactive moieties through the concept of molecular hybridization. Various spectral techniques such as FTIR, 1H NMR, 13C NMR, 2D NMR and HRMS were utilized for structural elucidation of the synthesized hybrids. The serial dilution method was employed for performing the antimicrobial activity of synthesized triazoles against four bacterial (S. aureus, B. subtilis, E. coli, K. pneumoniae) and two fungal (C. albicans, A. niger) strains. The antibacterial results demonstrated that a couple of hybrids show noteworthy outcomes related to standard medication. Compound 4r was indicated great action against E. coli with MIC values 0.0259 µmol/mL. Based on outcomes of antibacterial activity, molecular docking study was carried out with E. coli DNA gyrase to understand the binding behavior. To check out the drug-likeness, in silico ADME (Absorption, Distribution, Metabolism and Excretion) studies of synthesized hybrids were also analyzed and found that compounds can be developed as potential oral drug candidates. [Display omitted] [ABSTRACT FROM AUTHOR]

[Display omitted] • Synthesis and characterisation of twelve new substituted 3,4-dihydro-2 H -1,4-benzoxazine derivatives. • Compounds 2b and 4b showed promising antiproliferative activity against MCF-7 breast cancer and HCT-116 colon cancer cell lines. • 2b and 4b displayed a consistent binding mode to hHER2 and hJNK1 kinases. • 2b and 4b exhibited potent cytotoxic activity by disrupting cell membrane permeability, likely triggering both inflammatory and non-inflammatory cell death mechanisms. • In the HCT-116 cell line, 2b and 4b arrest the cell cycle in the S phase. The search for new agents targeting different forms of cell death is an important research focus for developing new and potent antitumor therapies. As a contribution to this endeavor, we have designed and synthesized a series of new substituted 3,4-dihydro-2 H -1,4-benzoxazine derivatives. These compounds have been evaluated for their efficacy against MCF-7 breast cancer and HCT-116 colon cancer cell lines. Overall, substituting this heterocycle led to improved antiproliferative activity compared to the unsubstituted derivative 1. The most active compounds, 2b and 4b , showed IC 50 values of 2.27 and 3.26 μM against MCF-7 cells and 4.44 and 7.63 μM against HCT-116 cells, respectively. To investigate the mechanism of action of the target compounds, the inhibition profile of 8 kinases involved in cell signaling was studied highlighting residual activity on HER2 and JNK1 kinases. 2b and 4b showed a consistent binding mode to both receptor kinases, establishing significant interactions with known and catalytically important domains and residues. Compounds 2b and 4b exhibit potent cytotoxic activity by disrupting cell membrane permeability, likely triggering both inflammatory and non-inflammatory cell death mechanisms. This dual capability increases their versatility in the treatment of different stages or types of tumors, providing greater flexibility in clinical applications. [ABSTRACT FROM AUTHOR]

[Display omitted] • Two biobased low viscosity photoactive benzoxazine monomers are synthesized. • DLP 3D printing can be conducted without adding diluent. • The 3D printing benzoxazine thermosets show high heat resistance. Preparing biobased benzoxazine resin through vat photopolymerization 3D printing is of great significance for its sustainable development and application in cutting-edge fields. In this work, biobased guaiacol and eugenol are used as phenol sources, while 2-(2-aminoethoxy) ethanol with flexible ether bonds is used as an amine source to create photoactive benzoxazine monomers, Eu-BzMA and Gu-BzMA. The viscosity of both monomers at room temperature is lower than 150 mPa·s, which can satisfy the requirements of digital light processing (DLP) 3D printing without adding diluents. The thermal and mechanical properties of the 3D printing benzoxazine resins are studied and the relationship between structure and properties is discussed by comparing the two molecules. Eu-BzMA resin has higher thermal decomposition temperature (T 5 = 343 °C), higher hardness (0.70 GPa), higher flexural stress (43.5 MPa) and flexural moduli (2.71 GPa); while, Gu-BzMA resin has higher glass transition temperature (176 °C). This is because Eu-BzMA resin shows higher cross-linking density, but contains more flexible structures formed by allyl crosslinking. In this article, a preparation strategy of low viscosity biobased photoactive benzoxazine is proposed and successfully applied to vat photopolymerization 3D printing. [ABSTRACT FROM AUTHOR]

Owing to the biological importance of 1,2,3-triazoles and benzoxazine-3(4H)-ones scaffolds, we have attempted to design and synthesize novel 1,2,3-traizoles linked to benzoxazin-3-one moiety. Indeed, a novel series of 1,4-disubstituted 1,2,3-triazoles containing 2H-1,4-benzoxazin- 3-(4H)-one were synthesized. The 1,2,3-triazoles were obtained in high yields by a double copper-catalyzed azide-alkyne click chemistry reaction between azides and corresponding propargylated benzoxazin-3-ones. These compounds incorporate both the 2H-benzo[b] (Rao et al., 2019; Fringuelli et al., 2009) [1,4]oxazin-3-one motif and two 1,2,3-triazole heterocycles. The synthesized molecules were characterized by spectroscopic techniques such 1H NMR, 13C NMR, FT-IR and elemental analysis. [Display omitted] • Developed a synthetic route for new 2H-benzo[b] [1,4]oxazin-3-one derivatives. • Utilized click chemistry to incorporate 1,2,3-triazole moieties. • Demonstrated efficient and regioselective formation of 1,2,3-triazoles. • High yield and purity of the synthesized compounds. • Comprehensive characterization of the new derivatives using NMR, IR, and elemental analysis. [ABSTRACT FROM AUTHOR]

Polybenzoxazine-imine hybrid resins with good thermal and mechanical properties, as well as excellent shape memory and recycling properties, were prepared from bio-based benzoxazine synthesized from vanillin and a biobased diamine derived from furylamine and benzaldehyde (V-bfa), terephthalaldehyde (TA), and Jeffamine T403. The films have good thermal, mechanical, and recycling properties, influenced by the ratio of V-bfa and TA. The higher the percentage of V-bfa, the better the thermal properties, thermal stability, and shape memory properties of the films, unfortunately, the film with 100 % V-bfa content (Btt-10) exhibited brittleness and could not be fully recovered. Surprisingly, the film with half the amount of v-bfa (Btt-11) has excellent shape memory properties, unfolding over 90° in just 12 s after folding and returning to its original shape in 20 s, moreover, the rate of shape fixation (R f) and the rate of shape recovery (R r) is 90.56 % and 95.56 %, respectively. Meanwhile, the thermal, mechanical, and shape memory properties of the film were also not damaged in any way even after three recycling cycles. Therefore, Btts film are very low carbon and environmentally friendly, complying with the requirement to reduce carbon emissions. [Display omitted] • Bio-benzoxazine-imine hybrid resins with good thermal and mechanical properties are prepared. • The films exhibit excellent shape memory properties. • The film shows stable thermal, thermal stability and mechanical properties even after 3 cycles of recycling. [ABSTRACT FROM AUTHOR]

Rosin polyether polyol was synthesized through the hydroxylation of rosin and epoxy. This polyol was then used to modify CO 2 -polyols for the synthesis of rosin-CO 2 -polyurethane (RPU) as a wood coating. Simultaneously, a rosin-based benzoxazine (SBZ) was prepared using sesamol, paraformaldehyde, and dehydroabietylamine, and 3D interpenetrating network system, RPU/SBZ, was formed. The two coatings were further examined. Research has demonstrated that both RPU and the RPU/SBZ 3D interpenetrating network system exhibit excellent mechanical properties, with the latter outperforming the former. The hydrophobic angle of the RPU/SBZ coating measures 119° and remains unchanged over a short period, while the initial water contact angle of the RPU coating is 85° and decreases by 2° shortly after application. The RPU/SBZ composite system coating demonstrates superior chemical resistance, gloss, and adhesion to wood compared to the RPU coating. Additionally, RPU- and RPU/SBZ-based composite system coatings exhibit exceptional flame retardancy as wood coatings. These findings hold significant implications for the development of high-value products in the coating industry. [Display omitted] • The synthesis of green sustainable rosin-CO 2 -based polyurethane has the characteristics of good mechanical properties. • Synthesis of natural based rosin-based benzoxazines. • RPU and SBZ interpenetrating system has good hydrophobicity, flame retardancy, thermal stability, chemical resistance. [ABSTRACT FROM AUTHOR]

A P/N-containing flame retardant, DOPOBH, was synthesized with salicylaldehyde, p -aminophenol, 9,10-dihydro-9-oxa-10-phosphophenanthrene-10-oxide (DOPO) and formaldehyde. The performance of DOPOBH in flame retardant modification of 4,4′-diaminodiphenyl sulfone(DDS)/diglycidyl ether of bisphenol A (DGEBA, E−44) system was studied in terms of limiting oxygen index (LOI), vertical burning testing (UL-94) and cone calorimeter test (CCT). When the phosphorus content was 1.5 wt% of the whole system, DOPOBH modified epoxy resin (EP/P 1.5) exhibited excellent flame retardancy (achieving a UL-94 V-0 rating and the LOI value of 35.2 %). Compared with pure EP, a 54.3 % decrease of peak heat release rate (PHRR) and ca. 5 times of residue (with an intumescent structure) was obtained with EP/P 1.5 in CCT. Based on the results of CCT, scanning electron microscope (SEM), thermal gravimetric analysis (TGA) and thermogravimetry-infrared spectroscopy (TG-IR), DOPOBH was verified to play important roles in both gas phase and solid phase. In addition, the addition of DOPOBH could improve the dielectric properties of epoxy resin and provide new strategies for high-performance applications in electronic packaging. [Display omitted] • Synthesis of a novel flame retardant, DOPOBH, incorporating P/N elements for enhanced fire resistance. • Successful modification of DDS/DGEBA epoxy system with DOPOBH, achieving UL-94 V-0 rating at 1.5 wt% phosphorus. • Remarkable flame retardancy demonstrated by a 54.3 % reduction in peak heat release rate (PHRR) and substantial residue formation. • Comprehensive analysis (CCT, SEM, TGA, TG-IR) confirms a dual flame retardant mechanism in both gas and solid phases. • DOPOBH enhances fire performance and improves dielectric properties, suggesting potential for electronic packaging applications. [ABSTRACT FROM AUTHOR]

In this study, a novel bio-based benzoxazine-terminated hyperbranched polyester (HB-Dfa) was designed and synthesized using renewable diphenolic acid and furfurylamine as raw materials through self-polymerization and Mannich condensation reaction. Meanwhile, the copolymers based on HB-Dfa and benzoxazine monomer (P-ddm) were prepared to investigate the effect of HB-Dfa on the properties of traditional benzoxazine. The chemical structure of HB-Dfa was elucidated by fourier transform infrared (FTIR) and nuclear magnetic resonance (1H NMR) spectroscopies. The curing behavior and curing kinetics were investigated by differential scanning calorimetry (DSC), showing that it possessed a low temperature of exothermic peak and activation energy value compared with the P-ddm. Hence, the curing process of P-ddm was facilitated by the introduction of HB-Dfa. The thermomechanical and thermal properties of P-ddm/HB-Dfa copolymers were determined by dynamic mechanical analysis (DMA) and thermogravimetric analysis (TGA), respectively. Compared with the pure P-ddm resin, the introduction of HB-Dfa remained most of glass transition temperature (T g), cross-linking density and thermal stability, which could promote the curing reaction and reduce the curing temperature of the copolymers. In addition, HB-Dfa exhibited a low dielectric constant (2.46 ≥ k ≥ 2.16) and a low dielectric loss (f ≤ 0.05) at frequencies range of 2–18 GHz, which could effectively modify the dielectric properties of the copolymer system. [Display omitted] • Fully bio-based benzoxazine-terminated hyperbranched polyesters was prepared. • HB-Dfa exhibits low activation energy and and soluble in various organic solvents. • Poly(HB-Dfa)s shows low dielectric constant at frequencies range of 2–18 GHz. • Copolymers with low cure temperature and dielectric constant and improved toughness. [ABSTRACT FROM AUTHOR]

Phenol-formaldehyde resins (Ph-Rs) have been invariably used for the last few decades as a binder/matrix in friction materials (FMs) in the industry owing to the ease of processing, excellent balance of brake-performance properties, commercial availability, and cost. However, Ph-Rs pose persistent environmental concerns due to emissions of harmful volatiles during processing (NH 3 , formaldehyde), apart from the challenge of limited shelf life (∼2–6 months). The present work aimed to address such issues by exploring the potential of five types of in-house synthesized Polybenzoxazines (PBZ) resins to develop brake pads for passenger cars. The composite brake pads' performance (physical, mechanical, and tribological) was compared with those based on Ph-R containing other identical ingredients in the same amount. PBZ-based brake pads exhibited notable advantages compared to PhR-based ones, such as an 8–87% increase in the fade ratio, a 9–41% higher wear resistance, and a 0.5 to 5.4 dBA reduction in noise levels. Interestingly, dimethyl substituted PBZ (PBZ-dma) based brake-pads showed the best tribological (10% lower sensitivity of μ to speed and pressure, 15–87% higher fade ratio, 35% higher wear resistance) and noise vibration performance (lower vibration and sound pressure levels by 2.8% and 0.51 dBA, respectively) apart from its 7% higher thermal stability and thermomechanical properties (∼67% higher storage modulus and 50% higher tanδ). Present work confirms the potential of PBZs (having unlimited shelf life) as the next-generation binders for FMs with superior braking performance and eco-friendliness. • A fully successful attempt to replace phenolics with severe drawbacks in brake pads. • A series of benzoxazine monomers proved superior to phenolics as binders in all performance properties. • Dimethyl-substituted PBZ-based pads showed the best performance. • These eco-friendly monomers, with unlimited shelf life, led to energy-saving & high yield of pads. [ABSTRACT FROM AUTHOR]

• Electron-donating substituent increased the polymerization activity of benzoxazine. • Electron-withdrawing substituent increased the heat resistance of polybenzoxazine. • Impacts of meta-substituents on thermal stability of polybenzoxazines were complex. The molecular structure of benzoxazine is closely related to its polymerization activity and the properties of its polymer. In this work, benzoxazines were successfully synthesized from phenol, paraformaldehyde and meta-substituted anilines. Their polymerization behaviors were discussed by non-isothermal differential scanning calorimetry (DSC). Moreover, the thermal properties of corresponding polybenzoxazines were evaluated using DSC and thermogravimetric analysis. The results showed that the electron-withdrawing substituent increased the polymerization temperature while the electron-donating substituent lowered the polymerization temperature. The glass transition temperature decreased for polybenzoxazine with electron-donating substituent but elevated for polybenzoxazine with electron-withdrawing substituent. Besides, the thermal stability and thermal degradation mechanism of polybenzoxazine were significantly affected by the substituent. This work supplied further insight in the structure-property relationship of benzoxazine resin. [Display omitted] [ABSTRACT FROM AUTHOR]

Agricultural waste by-products such as cashew nut shell liquid and rice husk ash were utilized for the syntheses of card-bisphenol (C) and precipitated bio-silica (S), respectively. A hydroxyl terminated card-bisphenol based benzoxazine resin (CHB) was synthesized and then converted it into soft-foam namely benzoxazine-co-urethane pre-polymer (CHB-UF) by polymerizing with hexamethylene diisocyanate (HMDI) in the absence of any catalysts or foaming agents. Subsequent thermal ring opening polymerization of CHB-UF at 200 °C provides poly(benzoxazine-co-urethane) hard-foam (PCHB-UF) with little shrinkage. Similarly, different weight ratios of precipitated bio-silica (0–15 wt%) reinforced bio-based PCHB-UF hard-foam composites (PCHB-UFS) were prepared to utilize them for high-k dielectrics and hydrophobic applications. The foam microstructure was ascertained through the field emission scanning electron microscopy (FE-SEM). The reinforcement of bio-silica into the CHB-UF foam increases the value of dielectric constant according to the increase in weight percentage concentration, which might be due to the reduction in volume of voids. The neat PCHB-UF possesses the value of dielectric constant of 7.04 with lower value of dielectric loss of 0.01. Similarly, the values of dielectric constant and dielectric loss of 15 wt% bio-silica reinforced composites (PCHB-UFS15) are 10.1 and 0.08 respectively. The PCHB-UFS15 has shown hydrophobic nature with the value of water contact angle of 135°. Data obtained from different studies suggest that the bio-foam composites obtained from sustainable sources can be considered as an efficient dielectric materials used for electronics insulation. [Display omitted] • Development of bio-based cellular structured materials of soft and hard foams through in-situ process. • Agricultural waste byproduct of cashew nut shell liquid was used as a source material. • Card-bisphenol based hydroxyl terminated benzoxazine (CHB) was synthesized. • Bio-based soft-foam (CHB-UF) namely urethane-co-benzoxazine in the absence of foaming agents. • Both the soft-foam and hard-foam possess the hydrophobic behavior and excellent dielectric properties. [ABSTRACT FROM AUTHOR]

The present study addresses an increasing interest in achieving low-temperature curing of benzoxazines by utilizing chemical substances with acid moieties of varying functionalities as curing catalysts. Specifically, cardanol-furfurylamine (1), card-bisphenol-furfurylamine (2), bisphenol-A-aniline (3) and bisphenol-F-aniline (4) based benzoxazines were chosen for curing studies. The selected catalysts were systematically applied into benzoxazines and its curing behavior was studied with minimum amount of 5 wt%. Catalysts, including those with carboxyl and N , N -dimethyl functionalities, were evaluated based on their performance, with a focus on their substituent effect on curing behavior. The results contribute to the identification of catalysts with optimal potential for achieving the efficient low-temperature curing of benzoxazines with an objective of utilizing them for wide area of applications. Among the catalysts studied, gallic acid was found to be the better catalyst and reduces the curing temperature to 130 °C. The conversion graph for both bisphenol-A-aniline benzoxazine (3) in the absence of catalysts and bisphenol-A-aniline benzoxazine in the presence of catalysts (3 s) have been studied by DSC analysis. The activation energy (E a) has been calculated using Kissinger-Ozawa method through DSC analysis. Data resulted from different catalysts used for curing of benzoxazines, it was inferred that the pK a values of the catalysts also play a crucial role in the polymerization of benzoxazines. Further, the study aims to meet the growing demand for efficient and economically viable low-temperature curing processes for benzoxazines. [Display omitted] • Cardanol-furfurylamine and card-bisphenol-furfuryalmine benzoxazines were synthesized. • Catalytic effect of acid and dimethyl catalysts with benzoxazines were studied. • The curing temperatures were found at low temperature. • The gallic acid catalyst was found to be the better catalyst and reduces the curing temperature to 130 °C [ABSTRACT FROM AUTHOR]

Conventional benzoxazine resins, in spite of their excellent thermo-mechanical properties and good solvent resistance, suffer from high curing temperatures and limited self-healing/ reprocessability. In this frame, bio-sourced phenol (Phloretic acid), various diols (Dodecandiol/PEG200/Ethylene glycol), and amine (monoethanolamine) have been used in appropriate proportions to synthesize innovative benzoxazine precursors bearing exchangeable ester functions following a solventless method. They can be directly handled and used for coating applications without using any solvent. The overall synthesis was followed by Nuclear Magnetic Resonance and Fourier transform infrared spectroscopy (FT-IR). The reduced curing temperature, thermal stability, good thermo-mechanical performance, and ester bond exchange-ability system were demonstrated by Differential Scanning Calorimetry (DSC), thermogravimetric analysis (TGA), and Dynamic mechanical analysis (DMA - stress relaxation testing), respectively. The elaborated resins were applied on etched aluminum 1050 without solvent and the corrosion resistance of the coatings was investigated by electrochemical impedance spectroscopy (EIS). The electrochemical results showed proper corrosion protection on aluminum substrates. The best result was obtained with Dodecandiol-based benzoxazine coating due to its longer aliphatic chain and hydrophobic property. Comparing this coating with an epoxy-based benchmark showed enhanced corrosion resistance for the benzoxazine after 50 days of immersion, making it an interesting candidate for future industrial use. • Bio-sourced benzoxazines resins were synthesized. • The crosslinked polymers have healing, repair, and recycling properties. • Solvent-free coatings were applied. • Coatings show good anticorrosion behavior on AA1050 aluminum alloy. [ABSTRACT FROM AUTHOR]

In the frame of developing sustainable, eco-friendly and high performance materials, microcrystalline cellulose modified through silane coupling agent (MCC Si) is used as a reinforcing agent of benzoxazine resin to manufacture composites at different loadings of 5, 10, 15, 20 wt%. The structural, morphological and crystallinity characterizations of the modified MCC were initially performed to scrutinize the changes and confirm the modification. Then, an investigation on the crosslinking process of the prepared composites was held through curing kinetic study employing isoconversional methods. The kinetic data revealed a decrease in the average values of activation energy and the pre-exponential factor, particularly for composite supplemented with 10% MCC Si, whereas all samples disclosed a tendency of an autocatalytic curing mechanism. Furthermore, the study of the dynamic mechanical properties and degradation features of the cured specimens, respectively, indicated a superior stiffness attributable to the good interaction between BA-a and MCC Si, and enhanced thermal stability for the composites compared to pristine resin. • Microcrystalline cellulose was functionalized using silane coupling agent. • The structural, thermal and morphological occurring changes on MCC were investigated. • Effect of MCCSi on the curing kinetic, dynamic-mechanical properties and thermal stability of benzoxazine is studied. [ABSTRACT FROM AUTHOR]

A new class of bio based polymer blends have been prepared from a modified chitosan based benzoxazine precursor (E-ch) and amino cellulose (AC). AC was derived from cellulose with excellent film-forming, biocompatibility and biodegradability property. E-ch was synthesized from eugenol, modified chitosan and paraformaldehyde. The chemical structure was confirmed by FT-IR and 1H NMR analyses. Bio films were prepared by mixing E-ch and AC with diluted acetic acid, in different ratios. These films were further cross-linked by applying heat, via ring-opening polymerization of benzoxazine without any curing agent. FT-IR and DSC were used to study the effects of AC on E-ch to form cross-linked network polymer films [poly(E-ch)/AC]. Hydrogen bonding interactions were found to exist between poly(E-ch) and AC. These kinds of interactions considerably improve the mechanical and thermal properties and char yield of the polymer films. Additionally, these biofilms; poly(E-ch) and poly(E-ch)/AC have been examined for bio-activity with S. aureus. It is confirmed that these bio-films are effective in inhibiting bio-film related infection. In a similar way, both the bio-films act against C. albicans and thus avoid the formation of mycological infection. These results expose that poly(E-ch) and AC bio-films are capable to act as anti-microbial and anti-fungal agents. • Eugenol-chitosan PBz/AC biofilm was prepared by simple and effective ROP method. • Flexible biofilms with improved thermal and mechanical properties were produced. • These biofilms also act as an efficient anti-microbial and anti-fungal agent. [ABSTRACT FROM AUTHOR]

In order to develop an environmentally benign flame retardant for unsaturated polyester resins (UPR), an effective intumescent flame retardant architecture based on chitosan (CH) and ammonium polyphosphate (APP) was successfully deposited on the surface of diatomite particles by Layer-by-layer (LbL) assembly. With nine bilayers of CH/APP coating, UPR/ 9 BL@Dia composites exhibiting LOI value of 25.7% and V -0 rating. Cone calorimetry test reveals that 9 BL@Dia reduces the peak heat release rate and total heat release of UPR by 40.8% and 18.1%, respectively. Due to the unique morphology of 9 BL@Dia particles, UPR/ 9 BL@Dia composites achieves greater thermal stability and higher char yields than pure UPR. Based on the investigation of the gas and condensed phase, flame retardant mechanism of n BL@Dia was proposed as that APP/CH was heated to form phosphate esters, and then combined with diatomite to form a more stable and firm carbon structure, which can improve the fire safety of UPR composites. Unlabelled Image • A bilayer polyelectrolytes coated Dia (n BL@Dia) was fabricated by LbL assembly. • Water contact angle(WCA) of Dia and n BL@Dia increased from 9.7 to 32.3 o. • After incorporation of 9 BL@Dia, the pHRR of UPR/ 9 BL@Dia was reduces by 40.8%. • The incorporation of n BL@Dia increases the fire safety of UPR composites. • Flame retardance of n BL@Dia exceed the addition effect of Dia, CH and APP. [ABSTRACT FROM AUTHOR]

Ceramic particles were utilized to improve thermal stability and ablation properties of carbon/phenolic (C/Ph) composites. In this study, zirconium carbide (ZrC) modified C/Ph composites were fabricated by vacuum impregnation method, and effects of ZrC content on thermal stability and ablation properties were investigated by thermogravimetry analysis and plasma wind tunnel test. Moreover, morphological characterization was carried out using X-ray diffraction, scanning electron microscopy and energy dispersive X-ray spectroscopy. Experimental results showed that increasing ZrC content could lead to an evident increase in char yield, but an observable reduction in linear ablation rates and back-face temperatures because of the formation of ZrO 2 layer on the ablation surface. The work provided an effective way to improve thermal stability and ablation properties of C/Ph composites. [ABSTRACT FROM AUTHOR]

[Display omitted] • A full bio-based binary benzoxazine monomer containing aldehyde group was synthesized. • The Schiff base and β-hydroxy ester make vitrimers have very low bond exchange activation energy. • The polybenzoxazine structure can improve the thermodynamic properties and hydrophobicity of vitrimers. • At 60 °C, CFRP can realize the rapid and non-destructive recycling of carbon fibers. The traditional carbon fiber reinforced polymers (CFRPs) matrix is a permanent 3D cross-linked network that is difficult to degrade and reprocess. In order to solve the closed-loop recycling of carbon fibers (CFs) and develop green economy. We synthesized aldehyde-containing bio-based benzoxazine (VD) from vanillin and 1,10-diaminodecane, the epoxy resin vitrimer matrix (P-AE-MV) was prepared by curing acrylpimaric acid diglycidyl ester (AE) with a Schiff base (MV) formed by 1,8-menthane diamine (MDA) and VD. Under the double dynamic covalent bond of Schiff base and β-hydroxy ester, P-AE-MV has a very low dynamic bond exchange activation energy E a = 48.1 kJ mol−1, which can realize the rapid topological rearrangement of polymer network, and give P-AE-MV excellent self-healing, shape memory, reprocessability and degradability. In addition, the introduction of polybenzoxazine (PBz) structure greatly improved the mechanical properties, thermal decomposition temperature, carbon yield and hydrophobicity of epoxy resin vitrimer, which is very suitable for CFRPs matrix. The CFRP (P-AE-MV-CF) prepared with P-AE-MV as matrix resin have good mechanical properties, reprocessability, shape memory and self-adhesion. Especially, it can be rapidly ammonolysis with n-butylamine under mild conditions (60 °C), achieving efficient and non-destructive recycling of CFs. This work provides an effective solution to promote the closed-loop recycling of CFs and the sustainable development of CFRPs using fully bio-based resources as raw materials. [ABSTRACT FROM AUTHOR]

For the benefit of meet the industrial demand of integrated circuits for low dielectric constant (k) and the environmental requirements of sustainable development, it is important to prepare biobased benzoxazine resin with low k and high heat resistance by solvent-free method. In this paper, the biobased monomer V-fa containing aldehyde group was synthesized by biobased raw materials furfurylamine and vanillin, and then reacted with amino-terminated polydimethylsiloxane (PDMS) to prepare benzoxazine monomer V-fa-pdms containing schiff base structure by a solvent-free method. Then, the monomer was cured to obtain biobased benzoxazine resin poly(V-fa-pdms) , and the heat resistance, mechanical and dielectric properties of poly(V-fa-pdms) were studied. The results indicate that the resin exhibits excellent thermal stability and toughness by combining benzoxazine and PDMS reasonably. The initial thermal decomposition temperature (T di , 5% thermogravimetric loss) is 387 °C, and the material also exhibits excellent dielectric properties. When the frequency increases from 1 Hz to 1 MHz, the k of the material decreases from 2.71 to 2.60, and the fluctuation range of dielectric loss is 0.0051–0.0049. With the increase of frequency, both k and dielectric loss show a downward trend. At the same time, the material shows good corrosion resistance in commonly used solvents. These excellent properties of poly(V-fa-pdms) are due to the existence of a high cross-linked network structure formed by multiple cross-linking sites in the polymer network and the combined effect of low k and high heat-resistant PDMS components. A biobased benzoxazine monomer V-fa-pdms was synthesized by a solvent-less method without any purification, and the cured resin exhibits low dielectric constant and high heat resistance. [Display omitted] • A biobased benzoxazine monomer V-fa-pdms was synthesized by a solvent-free method. • Results demonstrate poly(V-fa-pdms) have high heat resistance, it also exhibits low dielectric constant and dielectric loss. • The nature behind these attractive performances of poly(V-fa-pdms) was intensively investigated. [ABSTRACT FROM AUTHOR]

In this work, we synthesized and investigated three fully biobased benzoxazine matrices containing exchangeable ester bonds for natural fiber composites. The thermoset properties were investigated and the transesterification behavior was assessed. The obtained polymers show high tunability. Using isosorbide as the starting building block, the thermoset exhibits a glass transition of 130 °C, a tensile modulus of 2.5 GPa, and thermal stability leading to degradation occurring after 270 °C with 31% char at 800 °C. All formulations stress relax under catalyst-free conditions within minutes with properties recovery superior to 80%. Finally, flax composites were manufactured. We highlight strong affinities between the matrices and the fibers through high mechanical performances with a modulus over 30 GPa and stress at break of 400 MPa in the longitudinal direction. 5 GPa modulus and 47 MPa stress at break were found in the transverse direction. Excellent fire retardancy properties, with self-extinguishment and UL-94 V1 classification were obtained for the isosorbide-based/flax composite. The obtained composites were able to be welded with comparable results to glued ones, paving the way to processable laminates and stable cured prepreg perfectly suited for transportation-engineered applications. [ABSTRACT FROM AUTHOR]

• Synthesis of sustainable bifunctional polybenzoxazines from analogues of Curcuma longa. • Synthesized benzoxazines exhibit rapid photo-crosslinking on UV irradiation. • Benzoxazines show photoluminescence property with higher stokes shift. • Curcumin based polybenzoxazines possess almost superhydrophobic behavior. • Polybenzoxazines are corrosion resistant with high efficiency. Bifunctional polybenzoxazines have been developed using sustainable bio-phenol curcumin, paraformaldehyde with varying nature of monofunctional amines through Mannich condensation. The molecular structure of synthesized benzoxazines were confirmed by ATR-FTIR, 1HNMR and 13CNMR and high-resolution mass spectroscopic (HRMS) analyses. DSC thermograms were used to ascertain the curing behaviour of curcumin-based monomers. Thermal curing of Cu-api occurs at 192 °C and that of Cu-aa undergoes dual curing at 177 °C and 209 °C due to its inherent molecular structure. The thermal stability of synthesized polybenzoxazines was studied using TGA, Cu-a exhibits higher char yield of 63% due to higher aromatic content than that of other polybenzoxazines. The occurrence of dimerization (2π+2π cycloaddition) of curcumin based benzoxazines proceeds through conjugation present in the main chain of curcumin when exposed to UV irradiation, and was monitored through UV–visible spectroscopy. All the synthesized benzoxazine monomers were excited within the wavelength of UV range with occurrence of photoluminescence behaviour in visible region ranges between 448 nm and 530 nm. The value of band gap calculated for the curcumin-based monomers ranged from 3.55 to 3.77 eV. The explicit character of curcumin based benzoxazines can be exploited in the field of optical applications. The hydrophobic behaviour of polybenzoxazines was also studied and the highest water interface angle value of 146° was observed for poly(Cu-tfma) due to the presence of fluorine groups. Furthermore, the Cu-tfma coated cotton fabric was tested for its durability and the results indicated that these materials coated cotton fabrics are better suitable for sustainable high performance hydrophobic applications. The anti-corrosion studies indicated that the poly(Cu-api) coated on mild steel exhibits greater resistance towards corrosion amongst the other polybenzoxazines which can be potentially employed as coating in marine environments. [Display omitted] [ABSTRACT FROM AUTHOR]

Two kinds of benzoxazine monomers were synthesized by Mannich reaction with N,N -dimethyl- p -phenylenediamine and N,N -dimethylethylenediamine using polyformaldehyde, 4,4′-dihydroxydiphenylmethane as raw materials. Subsequently, quaternary ammonium functionalization was realized by Menshutkin reaction. The aromatic amine-based quaternary ammonium-functionalized polybenzoxazine (AQPBZ) and aliphatic amine-based quaternary ammonium-functionalized polybenzoxazine (LQPBZ) were synthesized by ring-opening polymerization. Polybenzoxazine anion exchange membrane (AEM) was prepared by solution casting method. The AQPBZ and LQPBZ AEMs exhibit micro-phase separated morphology clearly. LQPBZ AEM displays more large ion clusters and ion conductive channels due to the flexible alkyl connection between QA group and polybenzoxazine skeleton. AQPBZ and LQPBZ AEMs have the ionic conductivity of 75.5 mS/cm and 86.3 mS/cm at 80 °C and 100% relative humidity, respectively. AQPBZ and LQPBZ AEMs show excellent alkaline stability. After treated with 6 M sodium hydroxide solution at 80 °C for 240 h, they manitained the 49.8 mS/cm and 50.2 mS/cm, respectively. They also exhibit good oxidation stability and thermal stability. Their oxidation weight losses are 4.1% and 7.2% through Fenton test, respectively. Their Td 5 s are 325 °C and 289 °C, respectively. Quaternary ammonium-functionalized polybenzoxazine-based AEMs synthesized by Mannich reaction and Menshutkin reaction exhibted excellent ion exchange properties, alkali stability, thermal properties and oxidation stability. [Display omitted] • The highly crosslinked polybenzoxazine structure gives the membranes excellent dimensional stability. • The polybenzoxazine structure gives the membrane excellent alkali stability and oxidation stability. • The polybenzoxazine structure gives the film excellent thermal properties. • The combination of quaternary ammonium groups and polybenzoxazine structure gives the membrane excellent ionic conductivity. • Quaternary ammonium-functionalized polybenzoxazine used in AEMs. [ABSTRACT FROM AUTHOR]

• Silanized epoxy resins were used to prepare RTV silicone rubber. • Cyclohexyl epoxy group did better than glycidyl epoxy group in storability. • Epoxy POSS was first introduced to modify silicone coatings. • Final coatings showed good adhesion, heat-resistance and anticorrosion properties. • Thermal degradation mechanism was analyzed by TGA-FTIR. A series of coatings composed of hydroxyl-terminated methyl phenyl silicone rubber (PSi) and silanized epoxy resins (SERs) were prepared in a facile way. Four kinds of SERs with different structures and degree of functionality were synthesized successfully and used to modify the silicone coating. The obtained room temperature vulcanized (RTV) silicone coatings showed excellent adhesion, great heat resistance and anticorrosion properties. Compared with pure PSi, the coatings containing 25 wt% SERs showed better thermal properties, manifested as delayed degradation temperature and greatly increased char yield at 800℃. The adhesion of coatings all reached the highest level (degree 0) which exceeded that of pure PSi coating (degree 2). Furthermore, the anticorrosion property of the coatings in 5 wt% acid, alkaline, and saline environments was all improved. The incorporation of SERs improved the compatibility between the silicone rubber and epoxy resins, in which the epoxy group created more adhesion of cured blended coating and POSS led a significant enhancement in thermal and anticorrosive properties. Their combined effect endowed silicone coatings with more application prospects. [ABSTRACT FROM AUTHOR]

• The benzoxazine are completely made from bio-based resource. • The corresponding polymer has low dielectric constant and low dielectric loss. • The copolymer showed high protection efficiency as anti-corrosion coating. • This high protection efficiency can owe to the synergistic effect of different benzoxazine. In this paper a novel bio-based benzoxazine, dehydroabietylamine benzoxazine monomer (D-Bz), was synthesized and a series of copolymers were prepared by using D-Bz and two other bio-based benzoxazines 6-allyl-8-methoxy-3-octadecyl-3, 4-dihydro-2H-benzoxazine (S-Bz) and 6-allyl-3 –(furan-2-ylmethl)-8-methoxy-3, 4-dihydro-2H-benzoxazine (F-Bz). The structure, morphology and curing process are characterized by 1H nuclear magnetic resonance spectroscopy (1H NMR), mass spectrometry (MS), fourier transform infrared spectroscopy (FTIR), scanning electron microscope (SEM), differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). Electrochemical techniques such as open circuit voltage time (OCPT), Tafel and electrochemical impedance spectra (EIS) were used to study their electrochemical corrosion properties. Results show that among these copolymer, when the ratio of S-Bz: D-Bz: F-Bz is 1:6:3, the copolymer has good synergistic effects, showing a lower dielectric constant (2.47 at 1000 Hz), higher crosslink density (5.29*E−4 mol/ml), lower corrosion current (0.030 µA/cm2) and the best electrochemical corrosion efficiency (99.73%). [ABSTRACT FROM AUTHOR]

• Three di-functional benzoxazine monomers (BZ) were synthesized. • Cardanol aliphatic chains induce H-bonds reorganization. • Thermal stability is significantly improved for cardanol-based polyBZ. Cardanol is a bio-phenol used in the field of polybenzoxazine (polyBZ) due to its abundance, low cost, effectiveness, and ease of reaction. Its impact on the polymerization kinetic of benzoxazine as well as on the thermal stability has been hereby investigated. To this aim, three di-functional benzoxazine monomers (BZ) are synthesized by bridging with ethylene diamine either two phenols (di-phenol), one phenol and one cardanol (asymmetric card-phenol), or two cardanol moieties (di-cardanol). FT-IR measurements show that the presence of the cardanol aliphatic chain modifies the formation of hydrogen bonding network. These differences are highlighted in the chemorheology of polymerization, where the di-phenol BZ monomer shows an early vitrification explained by the formation of a high degree of H-bonding interactions during curing. An important feature of benzoxazines reactions, highlighted in this study, is that vitrification does not stop the polymerization process. Cardanol long alkyl side chain can cause a plasticizing effect and induces a lower degree of polymerization. This is observed through the decrease of the glass transition temperature (Tg) and the apparition of a β relaxation for cardanol-based polymers. Interestingly, the thermal stability is significantly improved for cardanol-based polyBZ, which can be the result of H-bonds reorganization in the system due to the cardanol aliphatic chains. [ABSTRACT FROM AUTHOR]

• Benzoxazin-2-one and -3-one derivatives were synthesized and biologically evaluated. • Antimycobacterial evaluation (MIC) and cytotoxicity (IC50) have been reported. • Oxoacetamide-isoniazid analogues were obtained and biologically evaluated. • Compound 8a has been computationally studied. This study examines in depth benzoxazine nucleus for antimycobacterial property. We synthesized some benzoxazin-2-one and benzoxazin-3-one derivatives, which were tested for activity against a panel of Mycobacterium tuberculosis (Mtb) strains, including H37Ra, H37Rv and some resistant strains. Several compounds displayed a high antimycobacterial activity and the three isoniazid analogue derivatives 8a-c exhibited a MIC range of 0.125–0.250 μg/mL (0.37–0.75 μM) against strain H37Ra, therefore lower than the isoniazid reference drug. Two benzoxazin-2-one derivatives, 1c and 5j , together with isoniazid-analogue compound 8a , also revealed low MIC values against resistant strains and proved highly selective for mycobacterial cells, compared to mammalian Vero cells. To predict whether molecule 8a is able to interact with the active site of InhA, we docked it into the crystal structure; indeed, during the molecular dynamic simulation the compound never left the protein pocket. The more active compounds were predicted for ADME properties and all proved to be potentially orally active in humans. [ABSTRACT FROM AUTHOR]

Endowing rigid polyurethane foam (PUF) with a good fire-retardancy is essential for improving fire safety. Chemical improvement in fire-retardancy by using reactive-type flame retardants is better because of the disadvantages of traditional additive-type flame retardants. A reactive flame retardant tri-glycidyl phosphate (POG), which was synthesized by using phosphorus oxychloride and glycidol, was bound to the cross-linked network structure of PUF. The effects of POG on the physical-mechanical properties, morphology, thermal stability and fire-retardancy of PUF system were systematically investigated. Research results showed that POG resulted in an improvement in the thermal insulation ability and a slight decrease in the compressive strength of PUF. Furthermore, thermogravimetric analysis certified that the thermal stability and the char yield at 700 °C of PUF were significantly enhanced by incorporating POG. The limiting oxygen index increased to 22.3% with rising loading of POG. Moreover, a 30.2% decline in total heat release was achieved, the time to flameout was significantly shortened. Additionally, the vertical burning test illustrated that POG effectively limited the spread of flame and eliminated melt dripping. Further study confirmed that the fire-retardancy of PUF was significantly improved by inhibiting flame in the gas phase and charring in condensed phase. • A more thermally stable oxazolidinone structure was formed in the PUF with reactive tri-glycidyl phosphate (POG). • POG limited the flame spread and eliminated the melt dripping behavior of PUF, the fire resistance was greatly improved. • The thermal stability and char yield of PUF were significantly improved and increased by POG. • A better thermal insulation was provided to the flame-retardant PUF. [ABSTRACT FROM AUTHOR]

• Trieugenol phosphate monomer was synthesized (TEP). • Alder-ene thermosets were synthesize by reaction with TEP and bismaleimides. • Flexible Alder-ene thermosets were synthesized for the first time. • Rigid and flexible materials exhibit excellent thermal properties. • Thermal degradation was elucidated. Performing thermostable materials such as phenolic or epoxy networks are classically obtained from petrobased and harmful monomers. In this study, alternative solutions based on renewable eugenol trifunctional monomer (TEP) are proposed. Thus, innovative biobased Alder-ene thermosets are prepared by reacting TEP with two different bismaleimides: N , N ′-1,3-phenylene bismaleimide (PhBMI) and polydimethylsiloxane bismaleimide (SiBMI) leading to different crosslinked aromatic networks. These materials exhibit various mechanical properties with very different T g values of −113 °C and 247 °C for SiBMI and PhBMI materials respectively. However, both thermosets exhibit excellent thermal properties with elevated degradation temperature and high char yield. The degradation behavior was studied using thermogravimetric analysis – Fourier transformed infrared spectroscopy (TGA-FTIR): only silicon compounds were observed for SiBMI, whereas phosphorus and carbonaceous products had specific signatures in degradation gases for PhBMI. Kinetic analysis of degradation confirmed those different behaviors. Our contribution with two original Alder-ene thermosets is an innovative way to develop sustainable versatile high-performant materials. [ABSTRACT FROM AUTHOR]

• Polysiloxane with aminopropyl-terminated pendant groups were synthesized. • The synthesized polysiloxane copolymers shows higher reactivity. • The mechanical properties and adhesion strength of the modified resins were improved greatly. • The modified coatings exhibited excellent antifouling performance. Marine biofouling is a catastrophic problem for maritime industries, which catches researchers' attention. Antifouling coatings have been proved to be an effective approach to against fouling organisms. Herein, we firstly synthesized polydimethylsiloxane with aminopropyl-terminated pendant groups (APDMS) through a ring opening polycondensation, and then APDMS was reacted with bisphenol A type epoxy resin (DGEBA) to form the epoxy modified polysiloxane-based resin (EAPDMS). The curing behavior of DGEBA/APDMS was studied by differential scanning calorimetry (DSC) with a non-isothermal curing method. The adhesion strength of EAPDMS was remarkably improved. The results of dynamic mechanical properties (DMA) and tensile tests showed an obvious enhancement of mechanical properties in the modified resin system. Marine field tests revealed that coatings exhibited excellent antifouling performance within 3 months. In brief, the EAPDMS coatings possess outstanding mechanical properties and excellent adhesion strength, showing high potential in the marine antifouling field. [ABSTRACT FROM AUTHOR]

A flame retardation property of polymer composites is being considered important to minimize the amount of heat release and the smoke production during the combustion. Therefore, this work aims to improve the flame retardation property of epoxy composites using ammonium polyphosphate (APP), one of the intumescent flame retardants (IFRs). However, APP could be migrated to the surface of composite due to the weak compatibility with epoxy resin. To prevent the migration, the surface modification method has taken place using various amines, acting as charring agent. In this study, we select the 4,4′-diaminodiphenylmethane (DDM) as both curing agent and charring agent for the surface modification on the APP, and their epoxy composites were prepared. Interestingly, we observe both the fast curing effect by analyzing the curing behavior of epoxy composite by Friedman method, and significant improvements of the thermal degradation, and flame retardancy of epoxy with adding the amine-modified APP (mAPP). Moreover, the epoxy/mAPP composites showed higher flame retardation properties and formed the compact char structures due to the attached DDM, which acted as an efficient charring agent to promote to form the carbonaceous char structures. Finally, we also found the correlation between the improvements of flame retardation properties, and char structures of epoxy composites by calculating the crosslink density (M c) using the theory of rubber elasticity. • Amine-modified ammonium polyphosphate was prepared via cationic ion exchange reaction with 4,4′-diaminodiphenylmethane. • The attached DDM can contribute to accelerate the curing and improve the flame retardation properties of epoxy composites.. • The relationship of flame retardation properties and char structure was found using theory of rubber elasticity. [ABSTRACT FROM AUTHOR]

Superhydrophobic surfaces are composed of low surface energy materials and micro/nano structures; however, in real applications, it is challenging to achieve surfaces that simultaneously have strong mechanical, chemical, and adhesive properties. We have made an acetone solution of benzoxazine, epoxy and mesoporous SiO 2 to form a superhydrophobic surface using spray coating. These superhydrophobic surfaces maintained their superhydrophobicity after a more than 2.9 m abrasion test under 1.6 kPa, can endure the acid and alkali corrosion for more than 12 h, and can reach first level adhesion to a tin plate. The reason of the simultaneously improvement in mechanical strength, chemical robustness, and adhesive properties is the self-similar, organic-inorganic interpenetrating structure and rational choice of components of formulation. With multifaceted robustness and scalability, these coatings should find potential use in harsh chemical engineering as well as in infrastructure and communication equipment. Unlabelled Image • Mechanical robustness superhydrophobic surface with excellent adhesive property was made. • Benzoxazine/epoxy/mesoporous SiO 2 is first reported to be used in superhydrophobic surface making. • Inorganic-organic interpenetrating structure is benefited for making a robustness superhydrophobic surface. [ABSTRACT FROM AUTHOR]

• A series of novel resveratrol-based benzoxazine resins have been successfully synthesized. • Only single isomer has been formed for each tri-functional benzoxazine monomer. • These resveratrol-based polybenzoxazines possess excellent thermal properties. • The polybenzoxazine derived from benzoxazine containing acetylene shows lowest flammability. A series of thermally stable resveratrol-based tri-functional benzoxazine resins have been synthesized using resveratrol, different amines (aniline, 4-chloroaniline and 3-aminophenylacetylene) and paraformaldehyde. The molecular structures of these benzoxazines have been characterized by 1H and 13C NMR spectroscopy and FT-IR spectroscopy. The assignments for the characteristic protons and carbons in oxazine rings are confirmed using two-dimensional (2D) NMR techniques, including 1H–1H NOESY and 1H–13C HMQC. Moreover, the ring-opening polymerization of benzoxazines is studied using in situ FT-IR and differential scanning calorimetry (DSC), and the thermal stability and the flammability of the polybenzoxazines are also investigated by thermogravimetric analysis (TGA) and micro-scale combustion calorimetry (MCC), respectively. In addition to the advantages of lowest melting and polymerization temperatures amongst these resveratrol-based, tri-functional benzoxazines, the corresponding polybenzoxazine derived from benzoxazine containing acetylene shows highest thermal stability with a Tg temperature higher than 350 °C, initial degradation temperature at 10% weight loss at 465 °C, and char yield of 74% at 800 °C in nitrogen atmosphere. Furthermore, this polybenzoxazine also exhibits exceptionally low heat release capacity (30.7 J g−1 K−1) and total heat release value (6.0 kJ/g). [ABSTRACT FROM AUTHOR]

• An encapsulate film of the novel composition of epoxy, phenoxy, and benzoxazine. • The EZ3/PET film exhibited only 47.5% permeation than PET film. • Readily process at environment condition using applicator by a bar coater. • The method has an excellent prospect for large area flexible electronics. Electronic devices based on organic materials readily degrade owing to moisture or oxygen. Encapsulation materials and films made of inorganic and organic materials have been studied to arrest degradation, and polymeric materials have become more desirable owing to their flexibility, transparency, and processability. In this study, polymeric composite films that are fabricated under atmospheric conditions are studied. The composite encapsulation films consist of a combination of bisphenol A phenoxy resin and epoxy resin (POL) and synthesized benzoxazine monomer (eugenol-based Eu-Bzo (EZ), bisphenol-S based BPS-SA-Bzo (PZ), and bisphenol-AF based BPAF-SA-Bzo (FZ)). The composite with benzoxazine exhibits superior barrier characteristics with a highly hydrophobic nature compared to POL. The composite film with 3% Eu-Bzo exhibits lower moisture permeation rate of 2.02 g m−2 d−1 with 90% transparency in comparison to POL (3.65 g m−2 d−1) and PET (4.25 g m−2 d−1). The novel composition of epoxy and phenoxy resins along with benzoxazine is a potential candidate for fabricating barrier materials for flexible printed organic electronics. [ABSTRACT FROM AUTHOR]

• High-performance bio-based polymers from largely available renewable feedstock. • Benzoxazine synthesis processes were eco-friendly as confirmed by sustainable metrics. • Cured polymers presented elevated degradation temperatures higher than 350 °C. • Glass transition temperatures of cured polymers reached 250 °C. • Cured polymers had elevated flexural strains compared to traditional thermosets. In this work is described the use of Cashew Nutshell Liquid (CNSL) and the lignin-derivative catechol as widely available renewable starting materials for the synthesis of BPA-free benzoxazines. The bio-based resins were obtained through an efficient eco-friendly method using microwave-irradiation as a heating source, producing resins with good yields. After characterization by Fourier transform infrared spectroscopy (FTIR), nuclear magnetic resonance Spectroscopy (1H and 13C NMR) and differential scanning calorimetry (DSC), these resins were combined in different ratios and then thermally (co)polymerized to obtain fully bio-based polybenzoxazines. These thermosets were studied by thermogravimetric analysis (TGA), dynamic mechanical analysis (DMA) and three-point flexural test, which showed elevated char yield (up to 40%) and good mechanical properties (T g above 200 °C). Sustainable metrics, E factor and Atom Economy, were also applied for the synthesis of the bio-based monomers demonstrating the greenness of this process and suggesting that these materials can be considered interesting high-performance alternatives to substitute BPA-based polybenzoxazines. [ABSTRACT FROM AUTHOR]

Abstract Firstly, a benzoxazine-type silane coupling agent (BS) was synthesized using 3-aminopropyltriethoxysilane (KH-550), 3-N-pentadecylphenol and paraformaldehyde. Subsequently, modified amorphous zirconia (ZrO 2) nanoparticles (NPs) were obtained through sol-gel method in ethanol with zirconium-butoxide (Zr(OBu)4) and the synthesized BS as dispersant. FTIR spectra confirmed the existence of BS structure on the surface of the synthesized ZrO 2 particle. The results of DLS showed that the modified NPs possessed small particle size of 20–70 mm with low polydispersity index and stable dispersion performance which was consistent with the morphology observed in TEM. The zeta potential was proportional to the addictive BS amount and reached the maximum when the BS loading rate was 30 mol%. Bisphenol A epoxy resin (DGEBA) was cured with Bisphenol A benzoxazine and the modified ZrO 2 NPs were incorporated to prepare the epoxy/benzoxazine/ZrO 2 composite. Homogeneous dispersion of the modified NPs was observed in the cured composite which was in deep contrast with the unmodified one. The results of tensile test showed that the cured polymer with the BS modified NPs possessed promoted tensile strength. The maximum of tensile strength was 105.7 MPa derived from the BS3-3 group while that for the U3 group with the same content of unmodified ZrO 2 NPs was just 73.5 MPa. The critical point of the tensile stress moved toward higher NPs content for the composites including the BS modified NPs and the standard deviation of the results, especially for the tensile stress, decreased remarkably which mean more stable mechanical behavior. DMA results were in good consistence with the tensile test that the composites with the BS-modified NPs possessed higher glassy modulus and T g value. [ABSTRACT FROM AUTHOR]

A novel bio-based main chain benzoxazine with two oxazine rings and one phenolic hydroxyl group in the same aromatic ring was synthesized and characterized. The method includes the synthesis of polymeric benzoxazine precursors from simple chemicals such as gallic acid, gallic amide, 4,7,10-trioxa-1,13-tridecanediamine and formaldehyde by using traditional main chain synthesis methodology. The precursors were successfully characterized by the spectral and thermal investigations using 1H NMR, FTIR, GPC, DSC and TGA. The results demonstrated that phenolic hydroxyl groups in the benzene ring which are adjacent to the two oxazine rings have a great effect to reduce ROP temperature of benzoxazines. The clear reduction in ROP temperature was demonstrated by tracking exotherm in DSC analysis with an onset value at 126 °C. Moreover, thermal stability of the final products were investigated by TGA and high char yields observed. Unlabelled Image [ABSTRACT FROM AUTHOR]

The present study reports for the first time the use of bio-based apigenin for polybenzoxazine synthesis. Apigenin comes under flavonoids family that is naturally available in fruits, vegetables, and many herbals abundantly. In this work, apigenin was reacted with furfurylamine/stearylamine and formaldehyde to form multifunctional bio-based benzoxazine monomers (AP-f and AP-s). This interaction was investigated by means of FT-IR, 1H-NMR, 13C-NMR spectroscopic techniques. The as-synthesized monomers, AP-f and AP-s are converted to bio-films by means of ring-opening polymerization with thermal treatment to form a well cross-linked network structure. DSC was used to study the curing behavior of benzoxazine, exhibiting lower curing temperature of 178 °C for AP-f and 226 °C for AP-s than the commercially available benzoxazine. The mechanical and thermal properties of the above-mentioned bio-films are characterized by UTM and TGA. These results reveal that apigenin and furfurylamine based bio-film has better tensile (94 MPa) and thermal stability up to 350 °C. Moreover, both the bio-films, poly(AP-f) and poly(AP-s) have been further investigated for bio-activity with S. aureus. It was confirmed that the bio-films was effective in preventing bio-film associated infection. In a similar way, both the bio-films acts against C-albicans and thus prevents the formation of fungal infection. This information reveals that apigenin-based polybenzoxazine bio-films are capable to be considered as anti-microbial and anti-fungal agents. Image 1 • Utilized renewable, bio-based and bio-degradable material to synthesize apigenin based polybenzoxazine film. • A biologically active natural compound, AP-PBz, improve the property of the benzoxazine resins providing an additional bio-property. • Bio-films reduce the hyphal development and acts as an active anti-biofilm agent. • Synthesized compounds tested in vitro are also harmless in vivo and have clinical relevance as alternative method for human pathogenesis. [ABSTRACT FROM AUTHOR]

Abstract This work reports the utilization of lignin, a renewable and biomass-based material, as an effective modifying agent for thermally stable and hydrophobic membranes based on crosslinked polybenzoxazine (CRPBz) to significantly enhance their permeation fluxes in pervaporation dehydration tests. Lignin could involve in the crosslinking reaction of polybenzoxazine so as to be chemically embedded in the polymer networks. In addition to the inherent hydrophilicity of lignin, lignin could release the hydrophilic groups (phenol and tertiary amine) of crosslinked polybenzoxazine with formation of hydrogen bonding with crosslinked polybenzoxazine, consequently to significantly enhance the hydrophilicity and water permeation fluxes of the studied membranes. With feeding a 70 wt% tetrahydrofuran aqueous solution at 25 °C, lignin modification increases the permeation flux of the CRPBz based membrane from 237 g m−2 h−1 to 490 g m−2 h−1 and separation factor from 11,920 to 19,440. Lignin modification significantly enhances the water permeation flux of the membrane without scarifying separation ability. A 3.4-folds of pervaporation separation index (PSI, the product of permeation flux and separation factor) has been demonstrated with the lignin modification. Similar performance has also been recorded on the tests on a 70 wt% isopropanol aqueous solution. The effect of lignin has been attributed to increase the membrane hydrophilicity for facilitating water permeation. The results demonstrate the wide application scopes of the lignin-modified CRPBz based membranes in pervaporation dehydration based on their high stability and hydrophilicity. Graphical abstract Image 1 Highlights • Lignin is a reactive modifier for crosslinked polybenzoxazine based membranes. • Lignin modification enhances membrane hydrophilicity with formation of hydrogen bonding. • An effective approach to increase water permeability and keep membrane selectivity is demonstrated. • A 3.4-times enhancement on pervaporation separation index has been achieved. [ABSTRACT FROM AUTHOR]

• Two tetrahydrophthalimide-functional benzoxazines were successfully synthesized. • Polymerization behavior and thermal properties were investigated. • Polymerization activation energy was calculated by Kissinger and Starink methods. • The predicated autocatalytic models were in excellent agreement with experimental results. Two benzoxazine monomers with attached tetrahydrophthalimide at para and ortho position have been synthesized via Mannich condensation. The chemical structures of obtained monomers have been confirmed by 1H and 13C nuclear magnetic resonance spectroscopy (NMR) and Fourier transform infrared spectroscopy (FT-IR). The ring-opening polymerization has been examined by differential scanning calorimetry (DSC) analysis, which reveals that the ortho -tetrahydrophthalimide benzoxazine monomer exhibits lower polymerization temperature compared with its para -counterpart. Besides, the kinetic parameters have been determined by non-isothermal DSC at various heating rates. The apparent activation energy values of para - and ortho -tetrahydrophthalimide functional benzoxazine monomers are determined to be 107.12 and 91.00 kJ/mol, respectively, according to the Starink method. In addition, the polymerization processes of both monomers can be well described by autocatalytic kinetic models. The predicted curves based on the developed models from this study fit well with the experimental DSC thermograms. Moreover, the thermal properties of polybenzoxazines have also been evaluated by dynamic mechanical analysis (DMA) and thermogravimetric analysis (TGA). [ABSTRACT FROM AUTHOR]

Abstract A benzoxazine grafted poly(γ-glutamic acid) (B-PGA) was successfully synthesized by esterification of poly (γ-glutamic acid) (γ-PGA) with benzoxazine (BX). Structural characterizations by FTIR, 1H-NMR, GPC and UV–Vis spectroscopy indicated that all of γ-PGA monomer units were not grafted by BX thoroughly, and the reaction time of 2 h was the optimum condition for obtaining the B-PGA product with 25% degree of conversion. After modification, the maximum absorption wavelengths (λ max) of γ-PGA was shifted from 260 to 272 nm due to the aromatic π→π* transition of BX in the B-PGA structure. For fluorescent properties, characteristic emission and excitation wavelengths of B-PGA including its fluorescence quantum yield were systematically analyzed. The results showed that the B-PGA exhibited strong fluorescence in bright green color by the influence of BX which functioned as a fluorophore. In addition, the B-PGA showed an interesting property of chemical sensing for Fe(III) ion which can be clearly observed by naked eyes from the changing of its photophysical properties such as color or fluorescence. Graphical abstract Image 1 Highlights • BX was used as a functional segment for grafting on γ-PGA via esterification reaction. • The chemical structure of grafted product (B-PGA) was characterized by FTIR, 1H-NMR and GPC. • The optimum reaction time was found to be 2 h, providing 25% degree of grafting. • The photophysical properties of B-PGA including sensing function toward Fe(III) ion were presented. [ABSTRACT FROM AUTHOR]