Preparation and properties of propargyl ether-terminated poly(imide siloxane)s and their composites

2020 ◽  
pp. 095400832095452
Author(s):  
Qing Ye ◽  
Qiaolong Yuan ◽  
Farong Huang
Keyword(s):  
Flexural Strength ◽  
Thermomechanical Analysis ◽  
Proton Nuclear Magnetic Resonance ◽  
Aromatic Diamine ◽  
The Novel ◽  
H Nmr ◽  
Chemical Structures ◽  
Propargyl Ether ◽  
Poly Imide ◽  
Thermal Stability Of

The novel propargyl ether-terminated oligo(imide siloxane)s (PTISs) based on 2,2’-bis(3,4-dicarboxyphenyl)hexafluoropropane dianhydride (6FDA), aminopropyl-terminated polydimethylsiloxane (APPS), 4,4’-diaminodiphenylmethane (MDA) and p-aminophenyl propargyl ether (APPE) were synthesized. The chemical structures of PTISs were characterized by proton nuclear magnetic resonance (1H NMR) and Fourier transform infrared spectroscopy (FTIR). The PTISs exhibited excellent solubility in organic solvent and had broad processing window. The T300 carbon fabric was used to reinforce the PTIS matrices and prepare the composites (T300CF/PTISs). The thermal stability of the cured PTISs was analyzed by thermogravimetric analysis (TGA). The dynamic thermal mechanical properties of the composites were measured by dynamic thermomechanical analysis (DMA). The results show that the temperature at 5% weight loss (Td5) and residual yield at 800°C (Yr800°C) of the cured PTISs in N2 increase with incorporation of the aromatic diamine, whereas the Yr800°C of the cured PTISs in air decreases with introduction of the aromatic diamine. The elasticity of the composite increases with incorporation of the aromatic diamine, and the peak temperature of loss factor for the composites are higher than 300°C. The flexural strength, tensile strength and interlaminar layer shear strength (ILSS) of the T300CF/PTIS composite display the values of 439 MPa, 427 MPa and 32 MPa at room temperature, respectively. The retention of the flexural strength and ILSS for the T300CF/PTIS composite are above 80% at 250°C.

Fluorinated s-Triazinyl Piperazines as Antimicrobial Agents

2011 ◽  
Vol 66 (7-8) ◽  
pp. 345-352 ◽  
Author(s):  
Rahul V. Patel ◽  
Premlata Kumari ◽  
Kishor H. Chikhalia
Keyword(s):  
Antimicrobial Agents ◽  
Inhibitory Concentration ◽  
Salmonella Typhi ◽  
The Novel ◽  
Proteus Vulgaris ◽  
Aspergillus Clavatus ◽  
H Nmr ◽  
Chemical Structures ◽  
Triazine Derivatives ◽  
C Nmr

A series of 1,3,5-triazine derivatives that contain 4-amino-2-trifl uoromethyl-benzonitrile, 8-hydroxyquinoline, and different piperazines as substituents at the carbon atoms of the triazine ring have been synthesized by a simple and efficient synthetic protocol. The chemical structures of the compounds were elucidated with the aid of IR, 1H NMR and 13C NMR spectroscopy, and elemental analysis. The antimicrobial activity of the compounds was tested against seven bacteria (Staphylococcus aureus MTCC 96, Bacillus cereus MTCC 619, Escherichia coli MTCC 739, Pseudomonas aeruginosa MTCC 741, Klebsiella pneumoniae MTCC 109, Salmonella typhi MTCC 733, Proteus vulgaris MTCC 1771) and four fungi (Aspergillus niger MTCC 282, Aspergillus fumigatus MTCC 343, Aspergillus clavatus MTCC 1323, Candida albicans MTCC 183). The results indicate that some of the novel s-triazines have noteworthy activity in minimum inhibitory concentration as well as agar diffusion tests.

Synthesis of Bis(2, 4-Dihydro-2H-3-(4-N-Maleimido) Phenyl -1, 3-Benzoxazine)Isopropane

2011 ◽  
Vol 287-290 ◽  
pp. 688-693
Author(s):  
Guo Tao ◽  
You Hui Xu ◽  
Gang Yang
Keyword(s):  
Maleic Anhydride ◽  
Target Object ◽  
The Novel ◽  
H Nmr ◽  
Chemical Structures ◽  
Ft Ir

The novel bis(2, 4-dihydro-2H-3-(4-N-maleimido) phenyl-1, 3-benzoxazine)isopropane (BMIPBI) was synthesized from maleic anhydride, p-nitroaniline, formaldehyde and 2,2-bis(4-hydr -oxyphenyl)propane by a few steps reactions via the N-(4-nitrophenyl)maleimide(NPMI), N-(4-amin -ophenyl)maleimide(APMI),1,3,5-three(4-(maleimido)phenyl)-1,3,5-triazine(TMIPT)intermediate production. The chemical structures of BMIPBI were confirmed by 1H-NMR, FT-IR and EA. The results show that the production was the target object BMIPBI. The synthesized condition had been studied too. The BMIPBI was a loosened yellow solid and the yield of product was 58.8%.

Halogenated sunflower oil as a precursor for synthesis of polysulfide polymer

e-Polymers ◽  
2016 ◽  
Vol 16 (1) ◽  
pp. 33-39 ◽  
Author(s):  
Samira Moqadam ◽  
Mehdi Salami-Kalajahi
Keyword(s):  
Sunflower Oil ◽  
Proton Nuclear Magnetic Resonance ◽  
Gravimetric Analysis ◽  
Scanning Calorimetry ◽  
X Ray ◽  
H Nmr ◽  
Ft Ir ◽  
Harsh Conditions ◽  
Thermal Stability Of ◽  
Polysulfide Polymer

AbstractPolysulfide polymers usually are prepared by the reaction of different dihalide compounds with disodium polysulfides. In this field, dihalides are expensive and produced from halogenation of organic compounds by different methods with harsh conditions. To overcome this problem, in this work, sunflower oil as polyunsaturated oil was used as precursor to produce polyhalide compound. In this field, double bonds of oil were applied as functional groups to halogenate the sunflower via benzoyl peroxide-catalyzed reaction with hydrochloric acid. Also, Na2S3 was synthesized via the reaction between sulfur and sodium hydroxide. Then, halogenated oil was reacted with Na2S3 to produce sunflower oil-based polysulfide polymer. Fourier transform infrared spectroscopy (FT-IR) and proton nuclear magnetic resonance (1H NMR) were used to characterize the structure of sunflower oil and synthesized polysulfide polymer. The content of halogenation was also obtained via energy-dispersive X-ray spectroscopy (EDX). Thermal stability of synthesized polymer was determined by means of thermal gravimetric analysis (TGA) and glass transition temperature was investigated by differential scanning calorimetry (DSC).

scholarly journals The “Wine-T1” NMR experiment for novel wine-metabolome fingerprinting with nuclear-spin relaxation

2019 ◽  
Vol 12 ◽  
pp. 02029 ◽  
Author(s):  
J.E. Herbert-Pucheta ◽  
I. Mejía-Fonseca ◽  
L.G. Zepeda-Vallejo ◽  
D. Milmo-Brittingham ◽  
G.P. Maya
Keyword(s):  
Chemical Shift ◽  
Nmr Spectra ◽  
Pulse Sequence ◽  
Proton Spin ◽  
Spin Lattice Relaxation ◽  
Proton Nuclear Magnetic Resonance ◽  
Resonance Spectroscopy ◽  
The Novel ◽  
Analytical Technique ◽  
H Nmr

In agreement with the draft resolution OENO-SCMA 17-618 at step 5 “Quantitation of glucose, malic acid, acetic acid, fumaric acid, shikimic acid and sorbic acid in wine using proton nuclear magnetic resonance spectroscopy (1H NMR)” said technique has been recently accepted within the OIV chair as a primary quantitative analytical technique for beverage analysis such as wine. However, poor chemical shift dispersion in 1H NMR spectra severely penalizes quantification within overlapped or crowded regions. To outflank said penalization and quantify metabolites in signal overcrowding situations, the novel “Wine-T1” experiment is proposed. The novel scheme comprises the addition of a second dimension, wherein the proton spin-lattice relaxation times (T1-{1H}) of each metabolite's spin-system is correlated to a chemical-shift dimension. The new experiment includes a water and ethanol signal pre-saturation module, prior to the T1 saturation-inversion recovery dimension in order to maximize signal-to-noise ratio of wine metabolome NMR spectra. “Wine-T1” pulse sequence can be adapted to all commercial spectrometers (Bruker, Varian/Agilent, Jeol) and with acquisition times in the order of minutes, it should be considered as a fast repetition method to produce a robust metabolome fingerprint that has not been described before, to the best of our knowledge.

Phosphorous-jointed epoxidized soybean oil and rice husk-based silica as the novel additives for improvement mechanical and flame retardant of epoxy resin

2020 ◽  
Vol 38 (1) ◽  
pp. 3-27 ◽  
Author(s):  
Cuong Manh Vu ◽  
Van-Huy Nguyen ◽  
Quang-Vu Bach
Keyword(s):  
Impact Strength ◽  
Flexural Strength ◽  
Soybean Oil ◽  
Epoxy Resin ◽  
Rice Husk ◽  
Critical Stress Intensity Factor ◽  
Epoxidized Soybean Oil ◽  
Proton Nuclear Magnetic Resonance ◽  
Limiting Oxygen Index ◽  
Chemical Structures

The combined effects of phosphorous-jointed epoxidized soybean oil and rice husk–based silica on the flammability and mechanical properties of epoxy resin were examined in detail. The chemical structures of the epoxidized soybean oil, phosphorous-jointed epoxidized soybean oil, and rice husk–based silica were confirmed using Fourier transform infrared spectroscopy and proton nuclear magnetic resonance. Many characteristics of the obtained composite materials were examined, such as the tensile properties, impact strength, flexural strength, critical stress intensity factor (KIC), dynamic mechanical analysis, and flammability. The incorporation of both 10 phr phosphorous-jointed epoxidized soybean oil and 20 phr rice husk–based silica into the epoxy resin yielded the optimum values of the flexural strength, tensile strength, impact strength, and KIC, with increases of 87.78%, 67.23%, 109.34%, and 111.32%, respectively, compared with pristine samples. The limiting oxygen index increased from 23.1% to 29.3%, the peak heat-release rate decreased by up to 37.2%, and the sample satisfied the UL94 V-0 rating.

Synthesis and properties of a benzoxazine monomer containing maleimide and biphenyl groups

2021 ◽  
pp. 095400832199674
Author(s):  
Tao Guo ◽  
Yang Fan ◽  
Chang Bo ◽  
Zhang Qi ◽  
Han Tao ◽  
...  
Keyword(s):  
Weight Loss ◽  
Loss Rate ◽  
Proton Nuclear Magnetic Resonance ◽  
Significant Weight Loss ◽  
Scanning Calorimetry ◽  
Weight Loss Rate ◽  
Reaction Heat ◽  
H Nmr ◽  
Curing Reaction ◽  
Dsc Curves

Benzoxazine resin exhibits excellent properties and is widely used in many fields. Herein, the synthesis of a novel compound, the bis(2,4-dihydro-2 H-3-(4- N-maleimido)phenyl-1,3-benzoxazinyl)biphenyl (BMIPBB), has been reported, which was synthesized by reacting N-(4-aminophenyl)maleimide (APMI), formaldehyde, and 4,4’-dihydroxybiphenyl. 1,3,5-three(4-(maleimido)phenyl)-1,3,5-triazine (TMIPT) was formed as an intermediate during the reaction. The proton nuclear magnetic resonance (1H-NMR) and Fourier transform-infrared (FTIR) spectroscopy experiments were conducted to determine the structure of BMIPBB. BMIPBB was obtained as a reddish-brown solid in 40.1% yield. The thermal properties of BMIPBB were investigated using differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) techniques. Analysis of the DSC curves revealed that the broad peak representing the release of curing reaction heat appeared in the temperature range of 140–330°C. The peak temperature was 242.59°C and the heat of the reaction was 393.82 J/g, indicating that the rate of the curing reaction was low and the heat of the reaction was high. Analysis of the TGA results revealed that the weight loss rate was 5% at 110°C. The monomer exhibited a significant weight loss in the range of 320–500°C. The compound lost 50% of its weight at a temperature of 427°C.

scholarly journals Putative imbalanced amino acid metabolism in rainbow trout long term fed a plant-based diet as revealed by 1H-NMR metabolomics

2021 ◽  
Vol 10 ◽  
Author(s):  
Catherine Deborde ◽  
Blandine Madji Hounoum ◽  
Annick Moing ◽  
Mickaël Maucourt ◽  
Daniel Jacob ◽  
...  
Keyword(s):  
Amino Acids ◽  
Rainbow Trout ◽  
Amino Acid ◽  
Amino Acid Content ◽  
Proton Nuclear Magnetic Resonance ◽  
Free Form ◽  
Metabolomic Analysis ◽  
Nmr Metabolomics ◽  
H Nmr

Abstract The long-term effect of a plant (P)-based diet was assessed by proton nuclear magnetic resonance (1H-NMR) metabolomics in rainbow trout fed a marine fish meal (FM)–fish oil (FO) diet (M), a P-based diet and a control commercial-like diet (C) starting with the first feeding. Growth performances were not heavily altered by long-term feeding on the P-based diet. An 1H-NMR metabolomic analysis of the feed revealed significantly different soluble chemical compound profiles between the diets. A set of soluble chemical compounds was found to be specific either to the P-based diet or to the M diet. Pterin, a biomarker of plant feedstuffs, was identified both in the P-based diet and in the plasma of fish fed the P-based diet. 1H-NMR metabolomic analysis on fish plasma and liver and muscle tissues at 6 and 48 h post feeding revealed significantly different profiles between the P-based diet and the M diet, while the C diet showed intermediate results. A higher amino acid content was found in the plasma of fish fed the P-based diet compared with the M diet after 48 h, suggesting either a delayed delivery of the amino acids or a lower amino acid utilisation in the P-based diet. This was associated with an accumulation of essential amino acids and the depletion of glutamine in the muscle, together with an accumulation of choline in the liver. Combined with an anticipated absorption of methionine and lysine supplemented in free form, the present results suggest an imbalanced essential amino acid supply for protein metabolism in the muscle and for specific functions of the liver.

scholarly journals Polyhedral oligomeric silsesquioxane (POSS)-modified phenolic resin: Synthesis and anti-oxidation properties

e-Polymers ◽  
2021 ◽  
Vol 21 (1) ◽  
pp. 316-326
Author(s):  
Bing Wang ◽  
Minxian Shi ◽  
Jie Ding ◽  
Zhixiong Huang
Keyword(s):  
Phenolic Resin ◽  
Polyhedral Oligomeric Silsesquioxane ◽  
Synthesis Process ◽  
H Nmr ◽  
Chemical Structures ◽  
Carbon Fiber Fabric ◽  
Oxidation Properties ◽  
Tg And Dtg ◽  
Oligomeric Silsesquioxane ◽  
Fiber Fabric

Abstract In this work, octamercapto polyhedral oligomeric silsesquioxane (POSS-8SH) and octaphenol polyhedral oligomeric silsesquioxane (POSS-8Phenol) were successfully synthetized. POSS-8Phenol was added into the synthesis process of liquid thermoset phenolic resin (PR) to obtain POSS-modified phenolic resin (POSS-PR). Chemical structures of POSS-8SH, POSS-8Phenol, and POSS-PR were confirmed by FTIR and 1H-NMR. TG and DTG analysis under different atmosphere showed that char yield of POSS-PR at 1,000°C increased from 58.6% to 65.2% in N2, which in air increased from 2.3% to 26.9% at 700°C. The maximum pyrolysis temperature in air increased from 543°C to 680°C, which meant better anti-oxidation properties. XRD results confirmed both POSS-8Phenol and POSS-PR-generated crystalline SiO2 in air, which could explain the improvement of anti-oxidation properties. SEM showed that the POSS-PR had phase separation during curing process. Finally, carbon fiber fabric-reinforced POSS-PR (C-POSS-PR) was prepared to verify the anti-oxidation properties of POSS-PR.

scholarly journals Cross-Linked Chitosan/Multi-Walled Carbon Nanotubes Composite as Ecofriendly Biocatalyst for Synthesis of Some Novel Benzil Bis-Thiazoles

Polymers ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1728
Author(s):  
Latifah A. Alshabanah ◽  
Sobhi M. Gomha ◽  
Laila A. Al-Mutabagani ◽  
Tariq Z. Abolibda ◽  
Nahed A. Abd El-Ghany ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Alternative Methods ◽  
Reaction Conditions ◽  
Chemical Structures ◽  
Weight Losses ◽  
Recyclable Catalysts ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes ◽  
Thermal Stability Of ◽  
Heterogeneous Biocatalyst

Aminohydrazide cross-linked chitosan (CLCS) and its MWCNTs (CLCS/MWCNTs) were formulated and utilized as a potent ecofriendly basic heterogeneous biocatalyst under ultrasonic irradiation for synthesis of two novel series of benzil bis-aryldiazenylthiazoles and benzil bis-arylhydrazonothiazolones from the reaction of benzil bis-thiosemicarbazone with 2-oxo-N′-arylpropanehydrazonoyl chlorides and ethyl 2-chloro-2-(2-phenylhydrazono) acetates, respectively. The chemical structures of the newly synthesized derivatives were elucidated by spectral data and alternative methods, where available. Additionally, their yield % was estimated using a traditional catalyst as TEA and green recyclable catalysts as CLCS and CLCS/MWCNTs composite in a comparative study. We observed that, under the same reaction conditions, the yield % of the desired products increased by changing TEA to CLCS then to CLCS/MWCNT from 72–78% to 79–83% to 84–87%, respectively. The thermal stability of the investigated samples could be arranged as CLCS/MWCNTs composite > CLCS > chitosan, where the weight losses of chitosan, CLCS and CLCS/MWCNTs composite at 500 °C were 65.46%, 57.95% and 53.29%, respectively.

scholarly journals Time–frequency analysis of serum with proton nuclear magnetic resonance for diagnosis of pancreatic cancer

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Asahi Sato ◽  
Toshihiko Masui ◽  
Akitada Yogo ◽  
Takashi Ito ◽  
Keiko Hirakawa ◽  
...  
Keyword(s):  
Pancreatic Cancer ◽  
Carbohydrate Antigen ◽  
Serum Markers ◽  
Proton Nuclear Magnetic Resonance ◽  
Serum Samples ◽  
Time Frequency ◽  
H Nmr ◽  
Free Induction ◽  
Short Time ◽  
Long Term Survivors

AbstractAlthough serum markers such as carcinoembryonic antigen (CEA) and carbohydrate antigen (CA19-9) have been widely used in screening for pancreatic cancer (PC), their sensitivity and specificity are unsatisfactory. Recently, a novel tool of analyzing serum using the short-time Fourier transform (STFT) of free induction decays (FIDs) obtained by 1H-NMR has been introduced. We for the first time evaluated the utility of this technology as a diagnostic tool for PC. Serum was obtained from PC patients before starting any treatments. Samples taken from individuals with benign diseases or donors for liver transplantation were obtained as controls. Serum samples from both groups underwent 1H-NMR and STFT of FIDs. STFT data were analyzed by partial least squares discriminant analysis (PLS-DA) to clarify whether differences were apparent between groups. As a result, PLS-DA score plots indicated that STFT of FIDs enabled effective classification of groups with and without PC. Additionally, in a subgroup of PC, long-term survivors (≥ 2 years) could be discriminated from short-term survivors (< 2 years), regardless of pathologic stage or CEA or CA19-9 levels. In conclusion, STFT of FIDs obtained from 1H-NMR have a potential to be a diagnostic and prognostic tool of PC.

Sign in / Sign up

Export Citation Format

Share Document