scholarly journals Developing Further Versatility in Benzoxazine Synthesis via Hydrolytic Ring-Opening

Polymers ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 694
Author(s):  
Shaoying Cui ◽  
Carlos R. Arza ◽  
Pablo Froimowicz ◽  
Hatsuo Ishida
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Differential Scanning Calorimetry ◽  
Ring Opening ◽  
Phenyl Substituent ◽  
Scanning Calorimetry ◽  
New Approach ◽  
Chemical Structures ◽  
Elementary Analysis ◽  
Oxazine Ring ◽  
Phenolic Derivatives

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.

scholarly journals Thermotropic Liquid-Crystalline Properties of Viologens Containing 4-n-alkylbenzenesulfonates

Crystals ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 77 ◽  
Author(s):  
Pradip Bhowmik ◽  
Anthony Chang ◽  
Jongin Kim ◽  
Erenz Dizon ◽  
Ronald Principe ◽  
...  
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Differential Scanning Calorimetry ◽  
Fourier Transform ◽  
Liquid Crystalline ◽  
Metathesis Reaction ◽  
Scanning Calorimetry ◽  
Chemical Structures ◽  
Nuclear Magnetic Resonance Spectra ◽  
13C Nuclear Magnetic Resonance ◽  
Melting Transitions

A series of viologens containing 4-n-alkylbenzenesulfonates were synthesized by the metathesis reaction of 4-n-alkylbenzenesulfonic acids or sodium 4-n-alkylbezenesulfonates with the respective viologen dibromide in alcohols. Their chemical structures were characterized by Fourier Transform Infrared, 1H and 13C Nuclear Magnetic Resonance spectra and elemental analysis. Their thermotropic liquid-crystalline (LC) properties were examined by differential scanning calorimetry and polarizing optical microscopy. They formed LC phases above their melting transitions and showed isotropic transitions. As expected, all the viologen salts had excellent stabilities in the temperature range of 278–295 °C as determined by thermogravimetric analysis.

Synthesis, characterization, and structures of zircona- and boracyclosiloxanes with ferrocenyl substituents

2002 ◽  
Vol 80 (11) ◽  
pp. 1469-1480 ◽  
Author(s):  
Karena Thieme ◽  
Sara C Bourke ◽  
Juan Zheng ◽  
Mark J MacLachlan ◽  
Fojan Zamanian ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Differential Scanning Calorimetry ◽  
Thermogravimetric Analysis ◽  
Ring Opening ◽  
Ring Opening Polymerization ◽  
The Novel ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Multinuclear Nmr Spectroscopy

The novel zirconatetraferrocenylcyclotrisiloxane Cp2Zr(OSiFc2)2O (6), dizirconatetraferrocenylcyclotetrasiloxane [Cp2Zr(OSiFc2)O]2 (7), boratetraferrocenylcyclotrisiloxane (C6H5)B(OSiFc2)2O (8), and diboratetraferrocenylcyclotetrasiloxane [(C6H5)B(OSiFc2)O]2 (9) with ferrocenyl (Fc = Fe(η-C5H4)(η-C5H5)) substituents at silicon have been prepared from the reactions of Cp2Zr(NMe2)2 and PhBCl2 with diferrocenylsilanediol Fc2Si(OH)2 (3) and tetraferrocenyldisiloxanediol [Fc2SiOH]2O (5). The compounds were characterized by mass spectrometry, elemental analysis, UV–vis, IR, Raman, and multinuclear NMR spectroscopy, as well as single crystal X-ray diffraction. Thermogravimetric analysis and differential scanning calorimetry investigation of 6–9 showed that the cycles decompose before they can undergo any thermal ring-opening polymerization. In addition, no polymerization was detected in the presence of either KOSiMe3 or HOTf. The bulky ferrocenyl substituents on the Si atoms are likely to be at least partially responsible for the inability of these heterocycles to undergo ring-opening polymerization. Key words: heterocyclosiloxanes, ferrocenyl.

scholarly journals Synthesis and characterization of solid 2-methoxycinnamylidenepyruvic acid

2008 ◽  
Vol 33 (4) ◽  
pp. 61-68 ◽  
Author(s):  
C. T. de Carvalho ◽  
A. B. Siqueira ◽  
E. Y. Ionashiro ◽  
M. Pivatto ◽  
M. Ionashiro
Keyword(s):  
Mass Spectrometry ◽  
Nuclear Magnetic Resonance ◽  
Differential Scanning Calorimetry ◽  
Infrared Spectroscopy ◽  
Magnetic Resonance ◽  
Molecular Geometry ◽  
Synthesis And Characterization ◽  
Scanning Calorimetry ◽  
Purity Determination

The 2-methoxycinnamylidenepyruvic acid (2-MeO-HCP) was synthesized and characterized for nuclear magnetic resonance (¹H and 13C NMR), mass spectrometry (MS), Infrared spectroscopy (FTIR) and differential scanning calorimetry (DSC). The application of DSC for purity determination is well documented in literature and is used in the analysis of pure organic compounds. The molecular geometry and vibrational frequencies of 2-MeO-HCP have been calculated.

New Waterborne Polyurethane Dispersions from the Soybean-Oil-Based Polyols by Ring Opening of ESO with Glycol

2011 ◽  
Vol 197-198 ◽  
pp. 1196-1200
Author(s):  
Kun Peng Wang ◽  
Li Ting Yang
Keyword(s):  
Differential Scanning Calorimetry ◽  
Soybean Oil ◽  
Thermophysical Properties ◽  
Ring Opening ◽  
Hard Segment ◽  
Waterborne Polyurethane ◽  
Hardness Testing ◽  
Scanning Calorimetry ◽  
Hard Segment Content ◽  
Polyurethane Dispersions

A series of polyols (GSOLs) with a range of hydroxyl numbers based on epoxidized soybean oil (ESO) were prepared by ring opening with glycol. These Polyols of hydroxyl (OH) numbers ranging from 111 to 162 mg KOH/g were obtained. The environmentally friendly soybean-oil-based waterborne polyurethane dispersions (SPU) with very promising properties have been successfully synthesized from a series of soybean-oil-based polyols (GSOLs) with different hydroxyl numbers by a polyaddition reaction with toluene 2,4-diisocyanate (2,4-TDI). The structure and thermophysical properties of the resulting SPU films have been studied by Fourier transform infrared spectroscopy, differential scanning calorimetry, thermogravimetric analysis, and hardness testing. The experimental results showed that the functionality of the GSOLs and the hard segment content play a key role in controlling the structure and the thermophysical properties of the SPU films.

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