Self termination of ring opening reaction of <i>p</i>‐substituted phenol‐based benzoxazines: An obstructive effect <i>via</i> intramolecular hydrogen bond

Chirachanchai, Suwabun; Laobuthee, Apirat; Phongtamrug, Suttinun

doi:10.1002/jhet.130

Cited by 68 publications

(52 citation statements)

References 13 publications

(28 reference statements)

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“…Moreover, many studies about the effects of different 24 reactant structures [13,16,[19][20][21][22], reactant ratios [23,24], reaction 25 temperatures [15], solvent effect [25], and reaction duration [22] 26 have also been reported; results showed that these conditions can 27 influence benzoxazine yield and generate various byproducts. 28 Many studies have focused on synthesizing novel benzoxazine 29 monomers [26][27][28].…”

Section: Q2mentioning

confidence: 98%

Study on products and reaction paths for synthesis of 3,4-dihydro-2H-3-phenyl-1,3-benzoxazine from phenol, aniline and formaldehyde

Zhang

Deng

Zhang

et al. 2015

Chinese Chemical Letters

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Section: Q2mentioning

confidence: 98%

Study on products and reaction paths for synthesis of 3,4-dihydro-2H-3-phenyl-1,3-benzoxazine from phenol, aniline and formaldehyde

Zhang

Deng

Zhang

et al. 2015

Chinese Chemical Letters

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“…Although these types of polymerization reactions are presented, Chirachanchai et al [40] stated that the polymerization of benzoxazine monomers does not proceed according to the theoretical mechanism even though the conditions, temperature, molar ratio, solvent polarity, and reactant ratio are varied. Obstructive effects on ringopening polymerization leading to unique structure of a dimer ( Figure 10) with inter-and intramolecular hydrogen bonds are leading to yet another speculated mechanism.…”

Section: Tg Studies: Thermal Stability Of Polybenzoxazinesmentioning

confidence: 99%

“…A detailed investigation [40] carried out allows one to conclude that the ring opening of p-substituted phenols provide neither linear oligomers nor polymers, but only dimers (Figures 10 and 11). …”

Section: Tg Studies: Thermal Stability Of Polybenzoxazinesmentioning

confidence: 99%

Structurally diverse benzoxazines: synthesis, polymerization, and thermal stability

Vijayakumar¹,

Rishwana²,

Surender³

et al. 2013

Designed Monomers and Polymers

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Bisphenol-A is converted to indane bisphenol and spirobiindane bisphenol. The compounds bisphenol-A benzoxazine (BAB), indane bisphenol benzoxazine (IBPB), and spirobiindane bisphenol benzoxazine (SBIB) are prepared by condensing the respective bisphenols with paraformaldehyde and aniline. The structural characterization of the synthesized materials is done by using FTIR, 1 H, and 13 C NMR. Curing behavior of these benzoxazines and glass transition temperature for polybenzoxazines are studied using differential scanning calorimeter (DSC). The curing exotherm of these benzoxazines is much influenced by the nature of the aromatic unit present in the chosen bisphenol. Compared to the aromatic nucleus in BAB, the indane nucleus present in IBPB shifts the cure exotherm to lower temperatures, whereas the biindane moiety present in SBIB shifts the same to high temperatures. These benzoxazines are thermally cured both at the onset and at the peak maximum of the curing exotherm. The thermal stability of these cured materials is investigated using thermogravimetry. The nature of the aromatic nucleus present in the bisphenol and the temperature at which the curing is done decide the glass transition temperature and thermal stability of the polybenzoxazine.

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“…The explanation for this observation is as follows: previous studies showed that polymerization of p-substituted phenol-based benzoxazines did not produce a linear polymer but only dimer, owing to the strong intramolecular hydrogen bond between the hydroxyl and nitrogen atom of the Mannich bridge which obstructed the polymerization. [13,14] As far as PC-a composites, the coordination interaction between lanthanum ion (or the other ions) and nitrogen atom destroys the OH . .…”

Section: Gpc Analysismentioning

confidence: 99%

Effect of Interaction between Transition Metal Oxides and Nitrogen Atoms on Thermal Stability of Polybenzoxazine

Zhu

2011

Journal of Macromolecular Science, Part B

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To investigate the interaction of transition metal oxides with polybenzoxazine and their influence on the thermal degradation mechanism of polybenzoxazine, transition metal oxides Y 2 O 3 , La 2 O 3 , Pr 6 O 11 , and Gd 2 O 3 were added to benzoxazine monomer based on p-cresol and aniline to prepare polybenzoxazine composites. The chemical structures and final polymerization extent of polybenzoxazine and its composites were characterized by Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), and differential scanning colorimetry (DSC). The molecular weights of these cured samples were determined by gel permeation chromatography (GPC). The influence of transition metal oxides on the thermal properties of polybenzoxazine matrix was investigated using dynamic mechanical analysis (DMA), thermogravimetric analysis (TGA), thermogravimetric analyzer interfaced with Fourier transform infrared spectroscopy (TG-IR), and (pyrolysis-gas chromatography-mass spectrometry)Py-GC-MS. The results show that transition metal oxides can form coordination interactions with the nitrogen atoms of polybenzoxazine. The coordination interaction can anchor the aniline and make the molecular weights of polybenzoxazine matrix increase, which delays evaporation of aniline during thermal degradation, improves the char yield at 800 • C, and increases the glass transition temperatures (T g ) of polybenzoxazine composites.

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Self termination of ring opening reaction of p‐substituted phenol‐based benzoxazines: An obstructive effect via intramolecular hydrogen bond

Cited by 68 publications

References 13 publications

Study on products and reaction paths for synthesis of 3,4-dihydro-2H-3-phenyl-1,3-benzoxazine from phenol, aniline and formaldehyde

Study on products and reaction paths for synthesis of 3,4-dihydro-2H-3-phenyl-1,3-benzoxazine from phenol, aniline and formaldehyde

Structurally diverse benzoxazines: synthesis, polymerization, and thermal stability

Effect of Interaction between Transition Metal Oxides and Nitrogen Atoms on Thermal Stability of Polybenzoxazine

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