Design and Synthesis of Bio-Based High-Performance Trioxazine Benzoxazine Resin via Natural Renewable Resources

A new fully biobased trioxazine benzoxazine is synthesized by reacting resveratrol, furfurylamine, and paraformaldehyde via the Mannich condensation reaction. The chemical structure of this biobenzoxazine is characterized by 1H and 13C nuclear magnetic resonance and Fourier transform infrared (FT-IR) spectroscopies. 1H-1H nuclear Overhauser effect spectroscopy is utilized to unambiguously identify the isomer obtained. Monomer polymerization is investigated by differential scanning calorimetry and in situ FT-IR. Thermal stability of the fully polymerized polybenzoxazine is evaluated by thermogravimetric analysis, and flammability is assessed by microscale combustion calorimetry. The biothermoset obtained shows high thermal stability and low flammability, Td10 of 403 °C and char yield of 64%, respectively, low heat release capacity (54 J/gK), and low total heat release (9.3 KJ/g), thus exhibiting self-extinguishing and nonignitable properties. Consequently, this new fully biobased trioxazine benzoxazine and its corresponding polybenzoxazine possess excellent processability and thermal properties, suggesting great potential toward high-performance and fire-resistant materials.Fil: Zhang, Kan. Jiangsu University; ChinaFil: Han, Mengchao. Jiangsu University; ChinaFil: Liu, Yuqi. Jiangsu University; ChinaFil: Froimowicz, Pablo. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Tecnología en Polímeros y Nanotecnología. Universidad de Buenos Aires. Facultad de Ingeniería. Instituto de Tecnología en Polímeros y Nanotecnología; Argentin

Developing Further Versatility in Benzoxazine Synthesis via Hydrolytic Ring-Opening

In this study, 2-(aminomethyl)phenol and its derivatives, the reactants for 2-substituted 1,3-benzoxazines, are synthesized by HCl hydrolysis from the typical benzoxazines. The phenol/ aniline-based mono-oxazine benzoxazine, PH-a, and the bisphenol A/aniline-based bis-oxazine benzoxazine, BA-a, are used as examples to demonstrate the feasibility of this new approach. Their chemical structures are characterized by nuclear magnetic resonance (NMR), Fourier transform infrared (FTIR) and Raman spectroscopies, and are further verified by elementary analysis. Their thermal properties are studied by differential scanning calorimetry (DSC). These two 2-(aminomethyl) phenolic derivatives are reacted with paraformaldehyde to close the oxazine rings. A benzoxazine with a phenyl substituent at the 2-position of the oxazine ring is obtained from the 2-(phenylamino)methyl)phenol (hPH-a) and benzaldehyde. All these results highlight the success of the HCl hydrolysis and the formation of stable intermediates, namely 2-(aminomethyl) phenolic derivatives, from readily available benzoxazine monomers. This further demonstrates the feasibility of using these intermediates as reactants for a novel benzoxazine synthesis.Fil: Cui, Shaoying. Sichuan University; ChinaFil: Arza, Carlos R.. Case Western Reserve University; Estados UnidosFil: Froimowicz, Pablo. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Tecnología en Polímeros y Nanotecnología. Universidad de Buenos Aires. Facultad de Ingeniería. Instituto de Tecnología en Polímeros y Nanotecnología; Argentina. Case Western Reserve University; Estados UnidosFil: Ishida, Hatsuo. Case Western Reserve University; Estados Unido

Electronic effects of asymmetric and meta-alkoxy substituents on the polymerization behavior of bis-benzoxazines

Three isomers of benzoxazine monomers based on m-alkoxyphenol and 4,4′-methylenedianiline were synthesized and successfully isolated by column chromatography. The molecular structures of benzoxazine monomers were confirmed by proton nuclear magnetic resonance (1H NMR) and Fourier-transform infrared (FT-IR) spectroscopy. The polymerization behavior evaluated by differential scanning calorimetry (DSC) shows that the asymmetric isomer, which has a methoxy group at the 5-position and 7-positions (5,7′MO-ddm), has only one exothermic peak between temperatures of the other two symmetric isomers. The 1H NMR spectrum of monomers shows that the type and position of alkoxy groups can exert different effects on the electron density of the oxazine ring, and may result in a sensitive trend of ring-opening. The difference in electron densities was verified by the Gaussian simulation calculation results of natural charges. In this work, we provide a fundamental molecular-level understanding of the polymerization mechanism of asymmetric bis-benzoxazines, which can provide possibilities for designing new benzoxazines in order to solve the potential disadvantages of benzoxazines/polybenzoxazines and/or enhance their advantages.Fil: Lyu, Ya. Case Western Reserve University; Estados UnidosFil: Rachita, Eric. Case Western Reserve University; Estados UnidosFil: Pogharian, Nicholas. Case Western Reserve University; Estados UnidosFil: Froimowicz, Pablo. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Tecnología en Polímeros y Nanotecnología. Universidad de Buenos Aires. Facultad de Ingeniería. Instituto de Tecnología en Polímeros y Nanotecnología; ArgentinaFil: Ishida, Hatsuo. Case Western Reserve University; Estados Unido

Design and Effects of the Cinnamic Acids Chemical Structures as Organocatalyst on the Polymerization of Benzoxazines

This study focuses on the catalytic effect of the two geometric isomers of a cinnamic acid derivative, E and Z-forms of 3-methoxycinnamic acid (3OMeCA), analyzing the influence of their chemical structures. E and Z-3OMeCA isomers show very good catalytic effect in the polymerization of benzoxazines, decreasing by 40 and 55 ◦C, respectively, the polymerization temperatures, for catalyst contents of up to 10% w/w. Isothermal polymerizations show that polymerizations are easily realized and analyzed at temperatures as low as 130 ◦C and at much shorter times using Z-3OMeCA instead of E-3OMeCA. Thus, both cinnamic acids are good catalysts, with Z-3OMeCA being better. The molecular reasons for this difference and mechanistic implications in benzoxazine polymerizations are also presented.Fil: Rodríguez, Rocío Belén. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Tecnología en Polímeros y Nanotecnología. Universidad de Buenos Aires. Facultad de Ingeniería. Instituto de Tecnología en Polímeros y Nanotecnología; ArgentinaFil: Iguchi, Daniela. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Tecnología en Polímeros y Nanotecnología. Universidad de Buenos Aires. Facultad de Ingeniería. Instituto de Tecnología en Polímeros y Nanotecnología; ArgentinaFil: Erra Balsells, Rosa. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Centro de Investigaciones en Hidratos de Carbono. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Centro de Investigaciones en Hidratos de Carbono; ArgentinaFil: Salum, Maria Laura. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Centro de Investigaciones en Hidratos de Carbono. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Centro de Investigaciones en Hidratos de Carbono; ArgentinaFil: Froimowicz, Pablo. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Tecnología en Polímeros y Nanotecnología. Universidad de Buenos Aires. Facultad de Ingeniería. Instituto de Tecnología en Polímeros y Nanotecnología; Argentin

Cupric Oxide Nanoleaves for the Oxidative Degradation of Methyl Orange without Heating or Light

Low-cost 2D cupric oxide nanoleaves (CuO NLs) arestraightforwardly synthesized at room temperature by precipitationvarying the addition method of the alkali. No further treatments arenecessary to obtain high purity NLs. The effect of the different additionmethods of alkali on the morphological, structural, vibrational, andoptical properties is studied by field emission scanning electronmicroscopy (FESEM), X-ray diffraction (XRD), and Fourier transforminfrared (FT-IR) and ultraviolet−visible (UV−vis) spectroscopies. NLsgrown by alkali addition in a dropwise manner are on average 281, 178,and 17 nm long, wide, and thick, respectively, and composed ofcrystallites of 14 nm corresponding to the crystallographic planes (1̅11)/(002) and (111)/(200). NLs obtained by this method agglomerateforming flower-like nanostructures, exhibiting indirect band gap energy of 1.21 eV. NLs grown by alkali addition in a one-stepmanner are on average significantly bigger, being 602, 219, and 26 nm long, wide, and thick, respectively, composed of crystallites of19 and 16 nm corresponding to the crystallographic planes (1̅11)/(002) and (111)/(200), respectively. These NLs agglomeraterandomly with no predominant form observed, exhibiting indirect band gap energy of 1.39 eV. The addition method of alkali doesnot influence the average crystallite size of NLs, whereas the microstrain distribution is sensitive to the initial concentration of OH−ions. Our results suggest that an indirect electronic transition between the valence and conduction bands might be more feasiblethan a direct one. NLs grown by the one-step method present the highest efficiency as catalyst toward catalytic oxidative degradationof the methyl orange dye with no heating and without the influence of light. Finally, this catalyst is easily recycled several timespreserving its high catalytic activity.Fil: Londoño Calderon, Cesar Leandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Tecnología en Polímeros y Nanotecnología. Universidad de Buenos Aires. Facultad de Ingeniería. Instituto de Tecnología en Polímeros y Nanotecnología; ArgentinaFil: Menchaca Nal, Sandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Tecnología en Polímeros y Nanotecnología. Universidad de Buenos Aires. Facultad de Ingeniería. Instituto de Tecnología en Polímeros y Nanotecnología; ArgentinaFil: Francois, Nora J.. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Tecnología en Polímeros y Nanotecnología. Universidad de Buenos Aires. Facultad de Ingeniería. Instituto de Tecnología en Polímeros y Nanotecnología; ArgentinaFil: Pampillo, Laura Gabriela. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Tecnologías y Ciencias de la Ingeniería "Hilario Fernández Long". Universidad de Buenos Aires. Facultad de Ingeniería. Instituto de Tecnologías y Ciencias de la Ingeniería "Hilario Fernández Long"; ArgentinaFil: Froimowicz, Pablo. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Tecnología en Polímeros y Nanotecnología. Universidad de Buenos Aires. Facultad de Ingeniería. Instituto de Tecnología en Polímeros y Nanotecnología; Argentin

Smart and sustainable design of latent catalyst-containing benzoxazine-bio-resins and application studies

A straightforward synthetic approach to incorporate a hydrogen-bonding motif as part of a fully biobased benzoxazine monomer (NAR-fa) is developed, leading to the first latent catalyst-containing thermosetting resin derived from natural renewable resources. The acronym is derived from the phenol (naringenin) and amine (furfurylamine) used in the synthesis. Interestingly, the newly developed benzoxazine resin exhibits a long shelf life in spite of possessing the lowest polymerization temperature reported hitherto for pure benzoxazines, 166 °C. The hydrogen-bonding motif is identified as an important design feature for studying the thermal behavior of the resin. All most common thermal and fire related properties, such as the glass transition temperature (Tg), temperature at which the weight loss is 5 and 10% (Td5 and Td10), char yield (Yc), limiting oxygen index (LOI), heat release capacity (HRC), and total heat released (THR), were far superior to those of typical polybenzoxazines. As a natural consequence of these great characteristics, NAR-fa was applied in small amounts (5 mol%) as an initiator and a property modifier of other petroleum-based and natural renewable resourced benzoxazine-based systems. The thermal properties of the resulting copolymeric thermosets were maintained or slightly enhanced, while those related to fire improved by about 38 and 51% for THR and HRC, respectively. These results highlight the utility of the latent catalyst-containing resin design derived from natural renewable resources in the preparation of high-performance resins and thermosets.Fil: Kan Zhang. Jiangsu University; ChinaFil: Yuqi Liu. Jiangsu University; ChinaFil: Mengchao Han. Jiangsu University; ChinaFil: Froimowicz, Pablo. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Tecnología en Polímeros y Nanotecnología. Universidad de Buenos Aires. Facultad de Ingeniería. Instituto de Tecnología en Polímeros y Nanotecnología; Argentin

New polyfunctional dendritic linear hybrids from terminal amine polyether oligomers (Jeffamine®): Synthesis and characterization

New dendritic polyether oligomers were synthesized from three different Jeffamines® and characterized. This class of polyfunctional oligomers, bearing on their surface methylester, carboxylic acid, nitrile or amine groups, could be interesting modifying agents to change the properties of materials. The optimization of the iterative synthetic methods, through Michael addition, hydrolysis or hydrogenation, gave first and second generation dendritic structures in good yields.Fil: Froimowicz, Pablo. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Departamento de Química Orgánica; Argentina. Grenoble Institute of Technology; FranciaFil: Gandini, Alessandro. Grenoble Institute of Technology; FranciaFil: Strumia, Miriam Cristina. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Departamento de Química Orgánica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentin

Application of Benzoxazine-Based Dimers, Oligomers, and Polymers as Chelating Agents

Polybenzoxazines are a relatively new type of thermoset polymer that has primarily been used for the development of composite materials. However, there is an existing interest in expanding the applications for this family of polymers. One way of achieving this goal is by taking advantage of the molecular structure, where the presence of oxygen and nitrogen atoms with lone electron pairs allows the formation of coordination complexes and chelates between the benzoxazine oligomers and polymers with metal ions. This article is focused on studying the relationship between the spatial conformation of the polybenzoxazine and the capacity to form coordination complexes from a fundamental point of view as well as practical applications of this concept. Thus, it can be seen that use of polybenzoxazines for the removal of heavy metals from water and the use of benzoxazine dimers for the synthesis of CeO2 nanoparticles are examples of very different applications based on the same working principle.Fil: Iguchi, Daniela. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Tecnología en Polímeros y Nanotecnología. Universidad de Buenos Aires. Facultad de Ingeniería. Instituto de Tecnología en Polímeros y Nanotecnología; ArgentinaFil: Salum, Maria Laura. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Centro de Investigaciones en Hidratos de Carbono. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Centro de Investigaciones en Hidratos de Carbono; ArgentinaFil: Froimowicz, Pablo. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Tecnología en Polímeros y Nanotecnología. Universidad de Buenos Aires. Facultad de Ingeniería. Instituto de Tecnología en Polímeros y Nanotecnología; Argentin

Triggering effect caused by elemental sulfur as a mean to reduce the polymerization temperature of benzoxazine monomers

Mixtures of different benzoxazine resins and elemental sulfur (S8) are prepared and then reacted at 120 °C, below the temperature for radical formation of sulfur. The progress of the reaction and the chemical structures of the main products are monitored and characterized by proton nuclear magnetic resonance spectroscopy (1H NMR) and Fourier transform infrared spectroscopy (FT-IR). Thermal analysis of all reactive systems are also performed and studied by differential scanning calorimetry (DSC). The introduction of S8 into benzoxazines generates a new structure bearing a Schiff base and a phenolic -OH within the reactive system, which then triggers the reduction of the polymerization temperature in about 15% when as low as 5 mol% of S8 is added.Fil: Rodriguez Arza, Carlos. Case Western Reserve University; Estados UnidosFil: Froimowicz, Pablo. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Tecnología en Polímeros y Nanotecnología. Universidad de Buenos Aires. Facultad de Ingeniería. Instituto de Tecnología en Polímeros y Nanotecnología; Argentina. Case Western Reserve University; Estados UnidosFil: Ishida, Hatsuo. Case Western Reserve University; Estados Unido