Synthesis of some novel Schiff bases containing 1,2,4-triazole ring

4-Allyl-5-piridine-4-yl-4H-1,2,4-triazole-3-thiol was prepared under facile condition via the formation of 2-isonicotinoyl-N-allylhydrazinecarbothioamide. In addition, ethyl[(4-allyl-5-pyridine-4-yl-4H-1¸2¸4-triazole-3-yl)thio]acetate was synthesized via the reaction of 4-allyl-5-piridine-4-yl-4H-1,2,4-triazole-3-thiol with ethyl chloroacetate. 2-[(4-Allyl-5-pyridine-4-yl-4H-1,2,4-triazole-3-yl)thio]acetohydrazide obtained by using ethyl[(4-allyl-5-pyridine-4-yl-4H-1¸2¸4-triazole-3-yl)thio]acetate as a precursor by two steps, was converted to Schiff base derivatives, 6a-j. All synthesized compounds were characterized by elemental analyses, IR spectroscopy, 1H NMR and 13C NMR spectroscopy. The cis/trans conformers of E isomer were present in DMSO solution of compounds 6a-j

Synthesis of a novel porous organic polymer containing triazine and cyclohexanone rings as an efficient methyl red adsorbent from aqueous solutions

Abstract In this research, a new porous organic polymer based on triazine and cyclohexanone rings was synthesized via Schiff base condensation, and its performance as an adsorbent for the removal of Methyl Red dye from aqueous solution was investigated. The synthesized polymer was characterized by FT-IR, XRD, SEM, EDS, TEM, TGA, and BET analyses. Five important parameters of pH (4–10), contact time (10–120 min), adsorbent dose (5–10 mg), initial dye concentration (10–70 mg/L), and temperature (25–45 °C) were investigated to optimize the adsorption conditions. Solution pH of 4, contact time of 80 min, adsorbent dose of 8 mg, initial dye concentration of 50 mg/L, and temperature of 45 °C were obtained as the best conditions for the adsorption of methyl red dye. Two widely used Langmuir and Freundlich models were employed to investigate the adsorption isotherm, and the obtained data showed that the adsorption process follows the Langmuir isotherm with a correlation coefficient (R2 = 0.9784) which indicates monolayer adsorption. The achieved maximum adsorption capacity was 178.57 mg/g. Also, the results of kinetic studies indicate that the adsorption process follows the pseudo-second-order kinetic, which suggests that chemical interactions play an important role in dye removal. Furthermore, the results showed that the adsorption process of methyl red dye by polymer is endothermic

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

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