Three component, one-pot synthesis of amidoalkyl naphthols using polyphosphate ester under solvent-free conditions

Amidoalkyl naphthols are synthesized via a simple, one-pot, three-component reaction between aldehydes, 2-naphthol and amides or ureas using polyphosphate ester (PPE) as a reaction mediator under solvent-free conditions in good to excellent yields. High yields, short reaction time, easy work-up, elimination of solvents and toxic catalysts are the advantages of this procedure

Synthesis of novel modified acrylamide copolymers for montmorillonite flocculants in water-based drilling fluid

Abstract A study was conducted to treat the water-based drilling fluid through coagulation-flocculation. Innovative modified acrylamide copolymers were utilized as montmorillonite flocculants to improve drilling performance and reduce environmental contamination. A series of acrylamide copolymers was prepared by in situ free radical polymerization in aqueous medium using ammonium persulfate as a radical initiator. The chemical structure of the prepared copolymers was confirmed by FT-IR (Fourier-Transform Infrared Spectroscopy) and the polydispersity indices of the copolymers determined using gel permeation chromatography. Thermal gravimetric analysis showed that the copolymers have a very high temperature tolerance, i.e. they are stable up to 390 °C. In this paper, acrylamide copolymers were used as coagulant with cationic, anionic groups or both of them simultaneously. Consequently, in order to clarify the relationship between inhibitive properties, sedimentation volume measurement, SEM (scanning electron microscope), XRD (X-ray diffraction) and contact angle were adopted. Some factors including molecular weight and molecular chain affecting the interaction between copolymers and clay particles were analyzed. Anionic sample with the highest molecular weight can reduce the interlayer spacing of the hydrated clay to the minimum. Amphoteric sample exhibits the best performance as a coagulant in comparison with other copolymers

Synthesis of water soluble ionic liquid copolymers based on acrylamide and investigation of their properties in flocculating of clay suspensions

Abstract To overcome water absorption and swelling by clay mineral layers, it is very important to develop stabilizing additives for water-based drilling fluids, where organic polymers are used as raw materials. Acrylamide copolymers, acting as flocculating agents, have the potential to separate minerals such as montmorillonite. In this study, three water-soluble copolymers containing acrylamide-amphoter, acrylamide-amphoter-anion, and acrylamide-amphoter-cation were synthesized and characterized using various analytical techniques, including Fourier-transform infrared spectroscopy, nuclear magnetic resonance, gel permeation chromatography, differential scanning calorimetry, thermogravimetric analysis, and derivative thermal gravimetric techniques. These copolymers were employed as flocculants to treat water suspensions containing montmorillonite particles, and a range of analytical methods, such as sedimentation volume measurement, scanning electron microscopy analysis, X-ray diffraction analysis, and contact angle measurement, were employed to identify the relationship between inhibitive performance. The flocculation of montmorillonite plates was attributed to the electrostatic attractions between montmorillonite and the synthesized copolymers. High molecular weight copolymers offer greater thermal stability and better flocculation characteristics for water-based drilling fluids. Among the tested copolymers, the acrylamide-amphoter-anion sample, with the highest molecular weight, exhibited the best performance as a coagulant when compared to the other copolymers

A DFT study of solvation effects and NBO analysis on the tautomerism of 1-substituted hydantoin

1-Substituted hydantoins (1-SH) have been known as a benefit intermediate for producing agricultural and pharmaceuticals. The effect of solvent polarity on the tautomeric equilibria of 1-substituted hydantoin ring is studied by the density functional theory calculation (B3LYP/6–31++G(d,p)) level for predominant tautomeric forms of hydantoin derivatives (1-NO2, 1-CF3, 1-Br, 1-H, 1-CHCH2, 1-OH, 1-CH3) in the gas phase and selected solvents (benzene (non-polar solvent), tetrahydrofuran (THF) (polar aprotic solvent) and water (protic solvent)). For electron withdrawing and releasing derivatives in the gas phase and solution Hy1 forms is more stable and dominant form. In addition variation of dipole moments and charges on atoms in the solvents are studied

Piperazine catalyzed convenient synthesis of 4H-pyran derivatives from α,α′-bis(substituted-benzylidene) cycloalkanones and malononitrile under reflux conditions

A facile, simple and convenient method for the synthesis of 4H-pyran derivatives has been achieved through the condensation reactions of α,α′-bis(substituted-benzylidene) cycloalkanones and malononitrile in the presence of piperazine as an odorless and easy to work catalyst under reflux conditions. With the optimized reaction conditions, the desired products were obtained with 62–82% yields

Theoretical Investigation of Solvation Effects on the Tautomerism of Maleic Hydrazide

A DFT study is used to calculate structural data of tautomers of maleic hydrazide (MH) in the gas phase and selected solvents such as benzene (non-polar solvent), tetrahydrofuran (polar aprotic solvent) and methanol (protic solvent), dimethyl sulfoxide (polar aprotic solvent) and water (protic solvent) using PCM model. All tautomers are optimized at the B3LYP/6−31++G(d,p). The results show that the tautomer MH2except in methanol is more stable than the other tautomers but in methanol MH5 (Diol) is more stable. In addition, stability of the tautomers in deferent solvents shows interesting results. Variation of dipole moments and NBO charges on atoms in the solvents were studied

Chitosan and imide-functional Fe 3 O 4 nanoparticles to prepare new xanthene based poly(ether-imide) nanocomposites

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