Synthesis and characterization of siloxane-containing benzoxazines with high thermal stability

Li, Hui; Xu, Jilei; Zeng, Kai; Li, Yuntao; Li, Chunxia Zhao Gaoxu

doi:10.1177/0954008319858130

Cited by 18 publications

(20 citation statements)

References 38 publications

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“…Monomers and prepolymers based on trimethoxysilyl‐ or triethoxysilylsilanes generate a three‐dimensional polysilsesquioxane network, and they have been subject of several investigations in the literature. [ 27–31 ] Regarding the benzoxazine field, functionalized organo‐silane monomers were scarcely reported. [ 17,21,28,32–40 ]…”

Section: Introductionmentioning

confidence: 99%

Tuning morphology of siloxane bond‐based polybenzoxazines by controlling the sol–gel and curing processes

Casarino

Bortolato

Estenoz

et al. 2021

Polymer Engineering & Sci

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Novel polybenzoxazine/polysilsesquioxane nanocomposites were synthesized with uniform and reproducible structural morphology, high Tg, and good thermal stability. Polysilsesquioxane was oriented in a nanometer‐size lamellar structure. Benzoxazine monomer based on silane (BA‐3aptms) was synthesized by reaction between bisphenol A, 3‐(trimethoxysilyl)propylamine, and paraformaldehyde in a 1:2:4 molar ratio. Four experimental conditions of the two stage sol–gel process for polysilsesquioxane were studied, and their effect on the material characteristics investigated. In the first stage, hydrolysis was favored, while the second stage mostly consisted of condensation. The reaction condition with the longest hydrolysis time allowed the increase of the concentration of silanol units and the selective condensation, favoring the formation of a higher amount of cage‐like cyclic structures. In addition, this experimental procedure was well controlled so that the sol–gel and oxazine‐ring opening reactions were extremely reproducible from batch to batch. All processes were monitored by Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis and dynamic mechanical thermal analysis, scanning electron and transmission electron microscopies, and X‐ray diffraction. A chemometric approach based on a multivariate curve resolution model was applied to the FTIR spectra, which allowed the identification of four reaction components associated with the sol–gel and the curing processes.

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Section: Introductionmentioning

confidence: 99%

Tuning morphology of siloxane bond‐based polybenzoxazines by controlling the sol–gel and curing processes

Casarino

Bortolato

Estenoz

et al. 2021

Polymer Engineering & Sci

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“…Benzoxazines can be an extremely interesting alternative to conventional organic resin systems. They represent a relatively new group of thermoset resins with some unique properties which can be very advantageous in abrasive technology [ 18 , 19 ]. Almost no polymerization shrinkage, low moisture absorption and high thermal stability are a set of desirable properties in such demanding applications [ 20 , 21 , 22 , 23 , 24 ].…”

Section: Introductionmentioning

confidence: 99%

Synthesis and Characterization of Low-Cost Cresol-Based Benzoxazine Resins as Potential Binders in Abrasive Composites

et al. 2020

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A series of cresol-based benzoxazines were synthesized for potential application as a polymer matrix in abrasive composites. The chemical structures of the obtained benzoxazine resins were investigated in detail using Fourier transform infrared spectroscopy (FTIR) and hydrogen-1 as well as carbon-13 nuclear magnetic resonance spectroscopy (1H NMR, 13C NMR) with an additional analysis using two-dimensional NMR techniques (2D NMR 1H-1H COSY, 1H-13C gHSQC and gHMBC). Structural analysis confirmed the presence of vibrations of -O-C-N- at ~950 cm−1 wavenumber, characteristic for an oxazine ring. The thermal properties of benzoxazine monomers were examined using differential scanning calorimetry (DSC) analysis. The polymerization enthalpy varied from 143.2 J/g to 287.8 J/g. Thermal stability of cresol-based benzoxazines was determined using thermogravimetry (TGA) analysis with additional analysis of the amount of volatile organic compounds (VOC) emitted from the synthesized benzoxazines during their crosslinking by static headspace coupled with gas chromatography technique (HS-GC). The amount of residual mass significantly differed between all synthesized polybenzoxazines in the range from 8.4% to 21.2%. The total VOC emission for benzoxazines decreased by 46–77% in reference to a conventional phenolic binder. The efficiency of abrasive composites with the benzoxazine matrix was evaluated based on abrasion tests. Performed analyses confirmed successful synthesis and proper chemical structure of cresol-based benzoxazines. All the experiments indicated that benzoxazines based on different cresol isomers significantly differ from each other. Good thermal performance and stability of the abrasive composites with the polybenzoxazine matrix and significantly lower VOC emission allow us to state that benzoxazines can be a promising and valuable alternative to the phenolics and a new path for the development of modern, eco-friendly abrasives.

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“…The primary amine selected is aminopropyl terminated polydimethylsiloxane (PDMS) that contains an elastomeric segment in its structure. Furfurylamine, a natural renewable amine, is chosen as a chain end to act as a cross-linkable group [ 39 , 40 ] to further enhance the cross-linking ability of benzoxazine. By using difunctional phenol and difunctional amine, a main-chain type benzoxazine polymeric precursor is synthesized, incorporating the benzoxazine unit as the chemical repeat unit.…”

Section: Introductionmentioning

confidence: 99%

Nacre-Mimetic Green Flame Retardant: Ultra-High Nanofiller Content, Thin Nanocomposite as an Effective Flame Retardant

et al. 2020

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A nacre-mimetic brick-and-mortar structure was used to develop a new flame-retardant technology. A second biomimetic approach was utilized to develop a non-flammable elastomeric benzoxazine for use as a polymer matrix that effectively adheres to the hydrophilic laponite nanofiller. A combination of laponite and benzoxazine is used to apply an ultra-high nanofiller content, thin nanocomposite coating on a polyurethane foam. The technology used is made environmentally friendly by eliminating the need to add any undesirable flame retardants, such as phosphorus additives or halogenated compounds. The very-thin coating on the polyurethane foam (PUF) is obtained through a single dip-coating. The structure of the polymer has been confirmed by proton nuclear magnetic resonance spectroscopy (1H NMR) and Fourier transform infrared spectroscopy (FTIR). The flammability of the polymer and nanocomposite was evaluated by heat release capacity using microscale combustion calorimetry (MCC). A material with heat release capacity (HRC) lower than 100 J/Kg is considered non-ignitable. The nanocomposite developed exhibits HRC of 22 J/Kg, which is well within the classification of a non-ignitable material. The cone calorimeter test was also used to investigate the flame retardancy of the nanocomposite’s thin film on polyurethane foam. This test confirms that the second peak of the heat release rate (HRR) decreased 62% or completely disappeared for the coated PUF with different loadings. Compression tests show an increase in the modulus of the PUF by 88% for the 4 wt% coating concentration. Upon repeated modulus tests, the rigidity decreases, approaching the modulus of the uncoated PUF. However, the effect of this repeated mechanical loading does not significantly affect the flame retarding performance.

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Synthesis and characterization of siloxane-containing benzoxazines with high thermal stability

Cited by 18 publications

References 38 publications

Tuning morphology of siloxane bond‐based polybenzoxazines by controlling the sol–gel and curing processes

Tuning morphology of siloxane bond‐based polybenzoxazines by controlling the sol–gel and curing processes

Synthesis and Characterization of Low-Cost Cresol-Based Benzoxazine Resins as Potential Binders in Abrasive Composites

Nacre-Mimetic Green Flame Retardant: Ultra-High Nanofiller Content, Thin Nanocomposite as an Effective Flame Retardant

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