pH-sensitive Itaconic acid based polymeric hydrogels for dye removal applications

A series of Itaconic Acid (IA) based pH-sensitive polymeric hydrogels were synthesized by condensation polymerization of Itaconic Acid (IA) with Ethylene Glycol (EG) in the presence of an acid medium resulted into pre-polymer. Further, pre-polymer were co-polymerized with Acrylic Acid (AA) through free radical polymerization using Potassium persulphate (KPS). The structural and surface morphological characterizations of the synthesized hydrogels were studied using FT-IR spectroscopy and Scanning Electron Microscope (SEM) respectively. The swelling and swelling equilibrium were performed at varies pH (4.0-10.0). Further, the effects of IA, EG and AA on swelling properties have also been investigated. Thermal stability of synthesized hydrogels have been investigated by TGA, DTA and DSC. The synthesized hydrogels have shown good ability to uptake a Cationic dye. The Methylene blue has been chosen as a model cationic dye. The results of dye removal using IA hydrogels found to have excellent dye removal capacity. Such kind of IA based hydrogels may be recommended for eco-friendly environmental application. viz., removal of dyes and metal ions and sewage water treatment, purification of water etc.

Investigation on pH-switchable (itaconic acid/ethylene glycol/acrylic acid) based polymeric biocompatible hydrogel

A new variety of pH-sensitive polymeric hydrogels (IAE) have been developed and evaluated as biocompatible hydrogels using synergetic combinations of itaconic acid (IA), acrylic acid (AA), and ethylene glycol (EG) in water medium by free radical polymerization.

Investigation of citric acid-glycerol based pH-sensitive biopolymeric hydrogels for dye removal applications: A green approach

Hydrogels are three dimensional polymeric structure with segments of hydrophilic groups. The special structure of hydrogels facilitates the diffusion of solutes into the interior network and possess numerous ionic and non-ionic functional groups, which can absorb or trap ionic dyes from waste water. The present investigation was devoted to the synthesis of a series of citric acid and glycerol based pH sensitive biopolymeric hydrogels using a solventless green approach via condensation polymerization in the presence of acidic medium. The formations of hydrogels were confirmed using various spectral investigations viz., FT-IR, (1)H and (13)C NMR. The thermal properties of various hydrogels have been studied using TGA, DTA and DSC analysis. The rationalized relationship was noticed with increasing of pH from 4.0 to 10.0. The surface morphologies of hydrogels were analyzed using SEM technique which was well supported from the results of swelling studies. Methylene blue has been selected as a cationic dye for its removal from various environmental sources using pH-sensitive biopolymeric hydrogels. The results of dye removal revealed that glycerol based biopolymeric hydrogels have shown an excellent dye removal capacity. Hence, the synthesized pH sensitive biopolymeric hydrogels have an adaptability with pH tuned properties might have greater potential opening in various environmental applications viz., metal ion removal, agrochemical release, purification of water, dye removal etc.

Synthetic investigation of glycine catalyzed triarylimidazole based organophosphorous heterocyclic functionalized vinyl polymer - A green approach

In the present investigation, an efficient and environmentally adopted synthesis of triaryl substituted imidazole in one-pot was reported. The multicomponent reaction between various aldehydes, benzil, benzoin, ammonium acetate and glycine under solvent free condition has been explained. Instead of using toxic reagents for the synthesis of heterocyclic compounds, Glycine has been selected as a green catalyst due to simple work-up procedure, shorter reaction time and high yield. The synthesized imidazole derivatives on further treatment with phosphorous oxychloride resulted in an organophosphorous containing N-heterocyclic compound (N-P) thus by altering acidic hydrogen of imidazole. Further, N-P was reacted with polyvinyl alcohol resulted into organophosphorous N-heterocyclic vinyl polymers. The synthesized vinyl polymers were characterized using, FTIR, NMR and Mass spectral studies. Results of the spectral studies were well supported the formation of the compounds. Thermal stability have also been studied using TGA.

Microwave assisted efficient synthesis of diphenyl substituted pyrazoles using PEG-600 as solvent - A green approach

A conventional and microwave assisted efficient synthesis of diphenyl substituted pyrazole using PEG 600 as green solvent has been described. A relatively shorter reaction time with excellent yield of the piperidine mediated protocol has been attracted economically attractive and eco-friendly. All newly synthesized compounds were characterized by standard spectroscopic techniques viz., UV-visible, FT-IR, (1)H-NMR and Mass spectra. The anti-microbial activities of compounds have also been tested using Minimum Inhibitory Concentration (MIC) method with two different microorganisms Staphylococcus aureus (MTCC3381) and Escherichia coli (MTCC739). The results of the antimicrobial activity revealed that the diphenyl substituted pyrazole derivatives have nice inhibiting nature against both types of bacteria of present investigation than corresponding chalcones. Since, the work has been focused on green chemical approach towards the synthesis, this protocol may be recommended for eco-friendly applications.

Synthesis and Properties of Nitrogen Heterocycle-Functionalized Core-Shell Hyperbranched Polyester

Core-shell hyperbranched polyesters (HBPE) of third generation prepared from 2,2′-bis (hydroxymethyl) propionic acid (Bis-MPA) as an ABx monomer and N-heterocyclic (indole, piperidine and piperazine) phosphoryl dichloride as a core molecule by melt condensation process. These polymers were characterized by FT-IR, 1H NMR, 13C NMR, 31P NMR, elemental analysis, and MALDI spectroscopy. The thermal behavior of the polymers has been investigated by thermo gravimetric analysis (TGA) and differential scanning calorimetry (DSC). There is no weight loss observed until 250 °C under nitrogen atmosphere. DSC showed that the glass transition temperatures was about −14 and −30 °C for the prepared core-shell HBPE. The dielectric properties such as dielectric constant and loss factor for these polyesters were also studied with respect to change of frequency (50 Hz to 5 MHz).