Studies on Non-Eugenol System Cement (III)

Anzai, Misaki; TOMOTSUNE, Kazuo; HASUI, Tadao; Kono, Koji; HARIMA, Toshihiko

doi:10.2334/josnusd1959.17.38

Cited by 3 publications

(4 citation statements)

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“…That is, the reaction product is presumably of hexacyclic structure. In this case, too, the IR spectrum showing OH absorption [2], it is presumed that hydrogen bonds C =0...H and H3C0 . .…”

Section: Examination Of the Reaction Mechanismmentioning

confidence: 75%

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Studies on Non-Eugenol System Cement (III)

Anzai

TOMOTSUNE

HASUI

et al. 1975

The Journal of Nihon University School of Dentistry

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“…That is, the reaction product is presumably of hexacyclic structure. In this case, too, the IR spectrum showing OH absorption [2], it is presumed that hydrogen bonds C =0...H and H3C0 . .…”

Section: Examination Of the Reaction Mechanismmentioning

confidence: 75%

“…That is, the reaction product is presumed to be of Zn-centered pentacyclic structure. But according to the IR spectrum of this chelate compound, the absorption due to the vibration of O-H faintly appearing, it is presumed that OH of phenol or O and H of OCH3 is partially joined by hydrogen bond [2].…”

Section: Examination Of the Reaction Mechanismmentioning

confidence: 95%

Studies on Non-Eugenol System Cement (III)

Anzai

TOMOTSUNE

HASUI

et al. 1975

The Journal of Nihon University School of Dentistry

Self Cite

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“…Thus, Zn 2+ will combine with the oxygen atoms of the methoxy group and hydroxyl group in guaiacol at the same time to form a five-membered chelate (Figure S10b). , …”

Section: Resultsmentioning

confidence: 99%

“…Thus, Zn 2+ will combine with the oxygen atoms of the methoxy group and hydroxyl group in guaiacol at the same time to form a five-membered chelate (Figure S10b). 51,52 To further investigate the specific interaction of Al•••H, 1 H NMR spectroscopy was employed to record the chemical shift change of guaiacol that was caused by the electron cloud density variation in the presence of Al 3+ . Figure 7 shows the chemical shifts change of the aromatic hydrogen with the increasing Al 3+ ratio.…”

Section: Resultsmentioning

confidence: 99%

Effect and Mechanism of Aluminum(III) for Guaiacol–Glyoxylic Acid Condensation Reaction in Vanillin Production

et al. 2020

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3-methoxy-4-hydroxymandelic acid (VMA) was the critical intermediate for the synthesis of vanillin by the glyoxylic acid method. Meanwhile, a valuable byproduct (2-hydroxy-3-methoxy-mandelic acid, o -VMA) was obtained during the reaction. Al 3+ was found to be a helpful catalyst in increasing the selectivity for VMA and o -VMA. In the presence of Al 3+ , the selectivity for VMA and o -VMA increased from 83 to 88% and from 3 to 8%, respectively, while that of the helpless byproduct 2-hydroxy-3-methoxy-1,5-mandelic acid (di-VMA) decreased from 14% to less than 4%. The kinetics based on the kinetic equation of the condensation reaction was studied by the initial concentration method. The results indicated that the involvement of Al 3+ could reduce the activation energy of the reaction on the basis of the Arrhenius equation. Combined with thermogravimetric analysis, in situ Fourier transform-infrared spectroscopy, and 1 H NMR research, Al 3+ was found to interact with guaiacol through Al–O and Al···H, which further improved the selectivity of the VMA and o -VMA and reduced the selectivity of di-VMA by adding the electronegativity of the ortho- and para-positions of hydroxyl groups of guaiacol.

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A Theory of Wood Waterproofing by Complexes of Metal Oxides with Lignin Structural Units

Kubel¹,

Pizzi²

1982

South African Forestry Journal

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SYNOPSISThe effect of various metallic oxides and hydroxides on wood waterproofing was investigated. 'The waterproofing effect was attributed to the type of complexes formed by the metallic oxide with the guaiacol units of the lignin network of wood. The type of structure of the complex formed, as well as its insolubility, contribute to the wood waterproofing, although to a different extent. Only Cr, Zn , Pb and Sn oxides formed insoluble complexes. Of these only Cr and Zn oxides are able to waterproof wood, although to a different extent. This was attributed to their capacity to further cross-link the lignin network in wood, which renders more difficult water penetration and improves wood dimensional stability. While it is necessary for the complexes formed to be insoluble, their insolubility is not the main contributing factor to wood waterproofing and its dimensional stabilisation.

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Studies on Non-Eugenol System Cement (III)

Cited by 3 publications

References 1 publication

Studies on Non-Eugenol System Cement (III)

Studies on Non-Eugenol System Cement (III)

Effect and Mechanism of Aluminum(III) for Guaiacol–Glyoxylic Acid Condensation Reaction in Vanillin Production

A Theory of Wood Waterproofing by Complexes of Metal Oxides with Lignin Structural Units

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