Preface

Ishida, Hiroyuki; Froimowicz, Pablo

doi:10.1016/b978-0-12-804170-3.09987-x

Cited by 44 publications

(77 citation statements)

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“…Greatening the proton concentration, by whichever method, shifts the equilibrium producing a higher amount of the protonated benzoxazine species ( Scheme 2 b), which in turn generates the more reactive cationic species, thus increasing the reaction rate of polymerization upon thermal treatment ( Scheme 2 d). The mechanism proposed herein is in full agreement with those previously accepted accelerated (or activated) polymerization mechanisms catalyzed by acid and acidic compounds intentionally added [ 16 ] or present as impurities [ 1 ] reported hitherto.…”

Section: Resultssupporting

confidence: 90%

“…Benzoxazines and polybenzoxazines, relatively new classes of resins and polymers [ 1 ], are increasingly attracting scientific and industrial interests due to a set of unusual and yet very desirable properties, such as high chemical [ 2 ] and thermal resistance [ 3 , 4 ], low flammability [ 5 , 6 ], near-zero shrinkage throughout polymerization [ 7 ], and excellent adhesive [ 8 ], and mechanicals properties [ 9 ]. Despite these advantages, the application of polybenzoxazines remains, in some cases, relatively impractical given the required high polymerization temperatures ( T p ), which implies the need of special precautions and high energy consumption.…”

Section: Introductionmentioning

confidence: 99%

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

et al. 2020

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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.

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Section: Resultssupporting

confidence: 90%

Section: Introductionmentioning

confidence: 99%

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

et al. 2020

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“…All of the above-mentioned circumstances emphasize the importance of further investigation of new organic binders that were not previously utilized in such applications. The resin system has recently gained popularity and benzoxazines broaden its range of applications [ 13 , 14 , 15 , 16 , 17 ]. Benzoxazines are a type of thermoset polymers which exhibit basic properties that meet the general requirements imposed by the abrasive industry.…”

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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“…As a new type of thermosetting resin, polybenzoxazines have many excellent properties like phenolic resin, such as excellent heat resistance, high char yield and good flame retardancy . Besides, polybenzoxazines also possess other properties that traditional phenolic resins lack, such as no release of small molecular byproducts and near‐zero volumetric shrinkage during curing, good dimensional stability, low water absorption and extraordinary flexibility in molecular design . These excellent properties enable polybenzoxazines to play a role in many application areas …”

Section: Introductionmentioning

confidence: 99%

Ring Opening Reaction of 3,4‐Dihydro‐2H‐1,3‐Benzoxazine with Amines at Room Temperature

Zong

Ran

2019

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The ring-opening reaction of p-cresol-based 1,3-benzoxazine with amine at room temperature was investigated in different solvents. Results show that the reactions proceeded easily in protic solvents, but no reaction occurred in aprotic solvents. For different amines involved in the reactions, both primary and secondary amines can participate in the reaction with benzoxazine, while tertiary amines would hinder the progress of the nucleophilic reaction. The mechanism study demonstrated the feasibility of polymerization of the benzoxazine with amines at room temperature. Moreover, the crosslinking between bifunctional benzoxazine and diamine was realized at room temperature, and the polymer can be obtained.[a] J. Zong, Q. Ran

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Preface

Cited by 44 publications

References 0 publications

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

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

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

Ring Opening Reaction of 3,4‐Dihydro‐2H‐1,3‐Benzoxazine with Amines at Room Temperature

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