Introduction
4-nitrophthalic naphthalic anhydride is used in dyes and pigments. It is also used in agrochemical, pharmaceutical. This Thermo Scientific Chemicals brand product was originally part of the Alfa Aesar product portfolio. Some documentation and label information may refer to the legacy brand.
1. REACTIONS OF 4-NITROPHTRALIC ANWDRIDE
Arynes are formed by the decomposition of aromatic dicarboxylic anhydrides at 7OOO.l Aryl radicals are formed by the dissociation of aromatic nitro compounds at 600′.* w, arynyl free radicals may be formed by the pyrolysis of aromatic dicarboxylic anhydrides substituted with nitro groups.
The postulated decomposition reactions may, of course, occur in discrete steps and, further, may be separated in the total reaction sequence by bondmaking processes with other molecules in the system. Nonetheless, extrapolation from the reactions of the monofunctional species furnishes a working hypothesis for those of the difunctional ones.
To test this hypothesis, we heated 7.05 g. (0.073 mole) of 4-nitrophthalic anhydride in 310 ml. (3.5 moles) of benzene at 650° for 32 seconds under nitrogen in a flow apparatus.3 The major products of the 23 g. total were biphenyl, terphenyl, and phenylnaphthalene, together with small amounts of phenylphthalic anhydride, terphenyldicarboxylic anhydride, and quaterphenyl.
The mechanisms by which these products were formed were clarified by reacting 4-nitrophthalic anhydride with benzene-& llvder identical conditions. Isotopic distributions of the major products are shown in Table I. Nearly all the biphenyl came from benzene-h alone; its relatively large proportion among the products was a result of the high benzene-to-nitrophthalic anhydride mole ratio, necessitated by the low solubility of the anhydride.
Phenylnaphthalenes, almost all -$, -410, and -ill, were evidently derived from two molecules of benzene-& and one of nitrophthalic anhydride, as were terphenyl-al and -32. Phenylnaphthalene and terphenyl species are most simply accounted for by arylation coupled with 1,4 addition and insertion, respectively, of a benzynyl free radical (II)
2. Measurement of Solid–Liquid Phase Equilibrium for the Ternary 3-Nitrophthalic Anhydride + 4-Nitrophthalic Anhydride + 1,4-Dioxane System
In this work, solid–liquid equilibria (SLE) data for the ternary 3-nitrophthalic anhydride + 4-nitrophthalic anhydride + 1,4-dioxane system were obtained at (283.15, 303.15, and 323.15) K. The solid–liquid phase diagrams of the ternary system were constructed based on the measured solubility data. There existed two pure solid phases at each temperature in the studied system, pure 3-nitrophthalic anhydride and 4-nitrophthalic anhydride,
which were identified by the wet residue method of Schreinemaker. Furthermore, the density (ρ) of the equilibrium liquid phase was determined. The ternary phase diagram and solubility data for the system 3-nitrophthalic anhydride + 4-nitrophthalic anhydride + 1,4-dioxane, which shows a much more practical application for the region where pure 3-nitrophthalic anhydride and 4-nitrophthalic anhydride are obtained, are much larger than those in the system with 2-propanone as a solvent.
3. Electrospun poly(bisphenol A-co-4-nitrophthalic anhydride-co-1,3- phenylenediamine) fibers: Preparation and potential for use in filtration applications
Abstract Poly(bisphenol A-co-4-nitrophthalic anhydride-co-1,3-phenylenediamine) (PEI) fibers were successfully prepared by electrospinning from PEI solutions in dichloromethane (DCM), 1,2-dichloroethane (DCE), N-methylpyrrolidone (NMP) and certain mixtures between NMP and N,N-dimethylformamide (DMF). Electrospinnability of PEI solutions in NMP was greater than that in DCM and DCE. The addition of DMF with NMP for the preparation of PEI solutions helped improve electrospinnability of the PEI solutions.
The effect of solution concentration on morphological appearance and/or size of the obtained products was investigated. At low concentrations of the PEI solutions, discrete beads and/or beaded fibers was formed. Smooth fibers were obtained at the highest concentration investigated, i.e., 20% (w/v). The size of the obtained fibers was found to be an increasing function with the solution concentration or, to be exact, the solution viscosity.
The water fluxes through the electrospun fiber mats prepared from 20% (w/v) PEI solutions in 75/25 and 50/50 NMP/DMF mixtures were investigated in comparison with the films prepared by phase immersion-precipitation technique. The fiber mats exhibited much greater fluxes of water than the films, which implied their potential for uses as filtration membranes.
Introduction
In the past decades, electrospinning has become a powerful and highly sought-after technique for fabricating ultrafine fibers with diameters in the range of tens of micrometers down to tens of nanometers. The principle of this technique is the application of electrical forces as the means for fiber formation (Doshi et al., 1995; Reneker et al., 2008).
When an electric field of a critical magnitude is applied to a polymer liquid (i.e., solution or melt), a pendant droplet of the polymer liquid at the open end of a capillary tip is deformed into a conical shape. Upon increasing the magnitude of the imposed electric field beyond a critical value, a stream of the charged polymer liquid (i.e., charged jet) is ejected towards a collection device and driven by the electrical forces.
Both, the Coulombic repulsion and electrostatic forces are responsible for the thinning of the charged jet during its flight to the collector. This usually results in the deposition of ultrafine polymeric fibers on a collector as a non-woven fibrous membrane. Due to the high surface area-to-volume or mass ratio and high porosity of the electrospun fibrous membranes…
1. Experimental Part
2.1 Materials
Poly(bisphenol A-co-4-nitrophthalic anhydride-co1,3-phenylenediamine) or poly(ether imide) (PEI) was purchased from Sigma-Aldrich (USA). The chemical structure of PEI is shown in Figure 1. Dichloromethane (DCM; LabScan (Asia),
Thailand), 1,2-dichloroethane
, N-methylpyrrolidone (NMP; Sigma-Aldrich, USA), and N,N-dimethylformamide (DMF; Lab-Scan (Asia), Thailand) were used as solvents for PEI.Poly(bisphenol A-co-4-nitrophthalic anhydride-co1,3-phenylenediamine) or poly(ether imide) (PEI) was purchased from Sigma-Aldrich (USA). The chemical structure of PEI is shown in Figure 1. Dichloromethane (DCM; LabScan (Asia),
Thailand), 1,2-dichloroethane (DCE; SigmaAldrich, USA), N-methylpyrrolidone (NMP; Sigma-Aldrich, USA), and N,N-dimethylformamide (DMF; Lab-Scan (Asia), Thailand) were used as solvents for PEI.
2.2 Preparation and characterization of spinning solutions and electrospun fiber mats
To investigate the effects of solvent type and solution concentration on morphological appearance and average diameters of the obtained fibers, PEI solutions were prepared by dissolving weighed amounts of PEI pellets in DCM, DCE, NMP, 75/25 (v/v) NMP, and DMF or 50/50 (v/v) NMP and DMF to achieve the concentrations of 10, 15, and 20% (w/v).
Prior to electrospinning, each of the spinning solutions was characterized for the shear viscosity using a Brookfield DV-II programmable viscometer at room temperature (i.e., 25±1°C). In electrospinning, each of the as-prepared spinning solutions was contained in a 5 mL syringe, the opening end of which was connected to a 20-gauge stainless steel needle (OD=0.91 mm) that was used as the nozzle.
A rotating drum (width and OD of the drum is 25 and 7.6 cm, respectively, rotational speed is 50 rpm) was used as a collector. The outer surface of the rotating drum was set at 10 cm from the tip of the needle. A Gamma High-Voltage Research ES30P-5W power supply was used to generate a high DC potential. The applied potential used was 15 kV and the polarity of the emitting electrode was positive. The collection time was fixed at about 5 min.
electrospun fiber mats used in the filtration test were prepared from 20% (w/v) PEI solutions in 75/25 and 50/50 (v/v) NMP/DMF, and the collection time was fixed at three hours. The thickness of the fiber mats was 130 µm on average.
2. Results and Discussion
3.1 Effect of solvent type
To investigate the effect of solvent type on morphological appearance of the electrospun PEI fibers, DCM, DCE, and NMP were chosen as the solvents because they were able to dissolve PEI over a reasonably wide range of concentrations investigated in this work.
It should be noted that tetrahydrofuran (THF) and DMF had also been tested, but no complete dissolution was observed when the concentrations of the solutions were greater than about 10% (w/v) (even the solutions had been continuously stirred for five days). THF and DMF were therefore proven to be inferior solvents for PEI to DCM, DCE and NMP.
To investigate the effect of solvent type, the solutions of 10, 15, and 20% (w/v) PEI in DCM, DCE, or NMP were electrospun at a fixed electric field of 15 kV/10 cm for 5 min. Figure 3 shows a series of SEM images of the products obtained from each type of solutions at the magnification of 500x. Equivalent images, but at a greater magnification of 3,500x, are shown in Figure 4.
Considering at 15 and 20% (w/v) of the PEI solutions, the numbers of the smooth or beaded fiber segments within a viewing area obtained from the solutions in NMP (see Figure 3h and i) were obviously greater than those obtained from the solutions in DCM (see Figure 3b and c) and DCE (see Figure 3e and f). In other words, the electrospinnability of the solutions was greater when NMP was used as the solvent, in comparison with DCM and DCE. The possible explanation of this should be…
2. Effect of solution concentration
The effect of solution concentration on the morphological appearance and size of the electrospun PEI fibers was also investigated and it can be evaluated from the results summarized in Figures 3 and 4. For the electrospun products from the 10% (w/v) PEI solution in DCM, discrete beads were the predominant features of the obtained products (see Figure 3a),
with trace amounts of beaded fibers with fine fibrous texture between adjacent beads being observed in a greatermagnification image (see Figure 4a). Increasing the solution concentration to 15 and 20% (w/v) resulted in the complete disappearance of the discrete beads, with flat ribbon-like fibers being the predominant features of the obtained products (see Figures 3, 4b, and c). The size of these fibers was relatively large (i.e., >10 mm on average) (see Table 2).
In case of the PEI solutions in DCE, a combination of discrete beads and beaded fibers was obtained at 10% (w/v) (see Figures 3 and 4d). Increasing the solution concentration to 15 and 20% (w/v) resulted in a dramatic decrease in the number of beads (see Figures 3, 4e, and f). Similar to the case of the fibers obtained from the solutions in DCM, flat ribbon-like fibers were the common features, with their size ranging between 6 and 7 mm on average…
3. Conclusions.
In the present contribution, electrospinning was used to fabricate PEI fibrous membranes for potential for uses in filtration applications. Electrospun fiber mats of PEI were prepared from the solutions in dichloromethane (DCM), 1,2- dichloroethane (DCE), N-methylpyrrolidone (NMP) and certain mixtures between NMP and N,N-dimethylformamide (DMF).
It was found that the electrospinnability of PEI solutions in NMP was greater than that of the solutions in DCM and DCE. Electrospinnability of the PEI solutions could be improved further with the use of DMF as the modifying cosolvent. The effect of solution concentration on the morphological appearance and size of the obtained products was investigated. At the lowest solution concentration investi…
4. Dicarboxylic acid anhydride condensation with compounds containing active methylene groups. 4: Some 4-nitrophthalic anhydride condensation reactions
By 4-nitrophthalic anhydride condensation with acetoacetate in acetic anhydride and triethylamine solution with subsequent breakdown of the intermediate condensation product, 5-nitroindanedione-1,3 was obtained. A 4-nitrophthalic anhydride with acetic anhydride, according to reaction conditions, may
yield two products: in the presence of potassium acetate and at high temperatures 4-(or 5-)-nitro-2-acetylbenzoic acid is formed: in the presence of triethylamine and at room temperature 5-( or 6-)-nitrophthalic acetic acid is isolated. A 4-nitrophthalic anhydride and malonic acid in pyridine solution according to temperature yield either 5-( or 6-)-nitrophthalic acetic acid or 4-(or 5-)-nitro-2-acetylbenzoic acid…
5. Measurement of Solid–Liquid Phase Equilibrium for the Ternary 3-Nitrophthalic Anhydride + 4-Nitrophthalic Anhydride + 1,4-Dioxane System
Abstract
In this work, solid–liquid equilibria (SLE) data for the ternary 3-nitrophthalic anhydride + 4-nitrophthalic anhydride + 1,4-dioxane system were obtained at (283.15, 303.15, and 323.15) K. The solid–liquid phase diagrams of the ternary system were constructed based on the measured solubility data.
There existed two pure solid phases at each temperature in the studied system, pure 3-nitrophthalic anhydride and 4-nitrophthalic anhydride, which were identified by the wet residue method of Schreinemaker. Furthermore, the density (ρ) of the equilibrium liquid phase was determined.
The ternary phase diagram and solubility data for the system 3-nitrophthalic anhydride + 4-nitrophthalic anhydride + 1,4-dioxane, which shows a much more practical application for the region where pure 3-nitrophthalic anhydride and 4-nitrophthalic anhydride are obtained, are much larger than those in the system with 2-propanone as a solvent.
6. Solid–Liquid Equilibrium and Phase Diagram for Ternary 2-Methyl-1,4-naphthoquinone + Phthalic Anhydride +1,4-Dioxane System
Abstract
The solid–liquid equilibria (SLE) in the ternary system of 2-methyl-1,4-naphthoquinone (2-MNQ) + phthalic anhydride (PA) + 1,4-dioxane were determined experimentally by using the isothermal dissolution equilibriam method within temperatures 283.15, 293.15, and 303.15 K, respectively. The ternary phase diagram could be helpful in the separation of 2-MNQ and PA.
On the basis of the experimental data on solubilities the phase diagrams of the system were plotted. Two pure solid phases were formed at 283.15, 293.15 and 303.15 K, including pure PA and pure 2-MNQ, which were confirmed and determined by Schreinemakers’ wet residue method. The phase diagram at 283.15 K is similar to those at 293.15 and 303.15 K and the crystalline regions of 2-MNQ and PA decrease with increasing temperature.
NRTL and Wilson model were employed to correlate and calculate the solubility data for the ternary system. A comparison between the two models shows that the NRTL model agrees better with the experimental data than those with the Wilson model. In addition, the densities of equilibrium liquid phase were obtained at the corresponding temperatures versus composition in the system.
7. Solid-liquid equilibrium for the ternary 2-naphthaldehyde + 2-methyl-1,4-naphthoquinone + ethanol system: Determination, correlation and molecular simulation
Abstract
In this work, the solubility of 2-methyl-1,4-naphthoquinone (2-MNQ, Vitamin K3) and its by-product 2-naphthaldehyde in binary and ternary systems was studied. Three phase diagrams were established based on the experimental solubility data. Each ternary phase diagram contains three crystallization regions (pure 2-MNQ, pure 2-naphthaldehyde and mixture of 2-MNQ and 2-naphthaldehyde), two co-saturated curves and one co-saturated point. The crystalline region of 2-MNQ is larger than that of 2-naphthaldehyde at three temperatures (283.15, 293.15 and 303.15) K. The solubility of the binary (2-MNQ + ethanol and 2-naphthaldehyde + ethanol) system was correlated by λh equation, modified Apelblat equation and NRTL model.
The ternary (2-MNQ + 2-naphthaldehyde + ethanol) system was correlated by NRTL model. The calculated values agree well with the determined solubility data. Interaction energy between solute and solvent molecules were calculated to illustrate the solubility behavior of 2-MNQ and 2-naphthaldehyde in ethanol.
RDF shows that when adding pure 2-naphthaldehyde in solution of 2-MNQ + ethanol, the interaction between 2-MNQ and ethanol molecules will become stronger, which leads to an increase in solubility of 2-methyl-1,4-naphthoquinone. This study can provide basic data and theoretical foundation for the separation process.
8. Solid–liquid phase equilibrium and phase diagram for ternary 3-nitrophthalic acid–4-nitrophthalic acid–water system at 283.15 K and 333.15 K
Abstract
In this investigation, the solid–liquid phase equilibrium and the mutual solubility for ternary 3-nitrophthalic acid–4-nitrophthalic acid–water system were determined at 283.15K and 333.15K. The phase diagrams of the system were constructed based on the measured solubility. The solid phases formed in the studied system were confirmed by Schreinemakers’ method of wet residues. In addition, the density of equilibrium liquid phase was obtained.
At 283.15K and 333.15K, both 3-nitrophthalic acid and 4-nitrophthalic acid were formed in the ternary 3-nitrophthalic acid–4-nitrophthalic acid–water system. Adductive compounds existed: 3:1:1 adduct 3-C6H3NO2(COOH)2·4-C6H3NO2(COOH)2·H2O at 283.15K and 1:1 adduct 3-C6H3NO2(COOH)2·4-C6H3NO2(COOH)2 at 333.15K. The adduct had a bigger crystallization field than 3-nitrophthalic acid or 4-nitrophthalic acid at each studied temperature.
The solubility data and the ternary phase diagram for the system 3-nitrophthalic acid–4-nitrophthalic acid–water at 283.15K and 333.15K can provide the fundamental basis for preparation of 3-nitrophthalic acid from 3-nitrophthalic acid and 4-nitrophthalic acid mixtures.
Question
1. What is 4 Nitrophthalic acid used for?
4-Nitrophthalic acid was used in the preparation of a 2D homochiral inorganic-organic framework {[Mn(4-nitrophthalate)(4,4′-bipyridine)(H2O)]·(H2O2}n by reacting with manganese ions, and ancillary 4,4′-bipyridine ligands[2].
2. What is 4 chloro naphthalic anhydride?
4-Chloro-1,8-naphthalic anhydride is used in dyes and pigments. It is also used in agrochemical, pharmaceutical. This Thermo Scientific Chemicals brand product was originally part of the Alfa Aesar product portfolio. Some documentation and label information may refer to the legacy brand.
3. What acid is used for face?
There’s only one primary BHA for your face: salicylic acid. This chemical exfoliation hero works deep down in your skin to unclog pores, soothe inflammation and promote a clearer complexion—making it one of the best acids for acne-prone skin.
4. What is 4 nitrophenol used for?
4-Nitrophenol is used to manufacture drugs, fungicides, insecticides, and dyes and to darken leather. Acute (short-term) inhalation or ingestion of 4-nitrophenol in humans causes headaches, drowsiness, nausea, and cyanosis (blue color in lips, ears, and fingernails). Contact with eyes causes irritation in humans.
5. What is acidity used for?
Acidic ingredients play an important role in flavor, adding bright, fresh notes and enhancing other ingredients, in particular providing balance to both bitterness and sweetness In addition, acids contribute to leavening in baking, and to tenderization in a variety of foods, such as proteins.
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