Showing papers by "Balbir Singh Kaith published in 2013"

Synthesis and properties of poly(acrylamide-aniline)-grafted gum ghatti based nanospikes

Abstract: In this work, we have synthesized poly(acrylamide-aniline)-grafted gum ghatti based crosslinked conducting hydrogel via a two-step synthesis method. The first step involved the microwave assisted synthesis of a semi-interpenetrating polymer network (semi-IPN) based on acrylamide and gum ghatti using N,N′-methylene-bis-acrylamide and ammonium persulfate as a crosslinker-initiator system. The semi-IPN has been observed to exhibit as much as 2183% swelling in aqueous solution. The effect of several variables such as time, solvent, pH, microwave power, crosslinker amount, aniline concentration, initiator concentration and monomer concentration on the swelling capacity was explored. In the final step, polyaniline was entrapped within a semi-IPN (optimized reaction condition) followed by doping with hydrochloric acid, which leads to the formation of conducting IPN. The synthesized hydrogels, as monitored by the swelling behaviour were characterized by Fourier transform infrared spectroscopy, X-ray diffraction, scanning electron microscopy and thermogravimetric analysis. Finally, the synthesized crosslinked networks have been used in malachite green (MG) adsorption. The result indicates that IPN of poly(acrylamide-aniline)-grafted gum ghatti are potential candidates for dye removal from water.

Enzyme-based green approach for the synthesis of gum tragacanth and acrylic acid cross-linked hydrogel: its utilization in controlled fertilizer release and enhancement of water-holding capacity of soil

Abstract: Enzyme lipase catalyzed graft copolymerization of acrylic acid onto gum tragacanth was carried out in an aqueous medium using glutaraldehyde as a cross-linker, one more step towards green chemistry. Various reaction variables such as time, amount of solvent, temperature, pH, lipase concentration, and monomer and cross-linker concentrations were optimized to achieve a cross-linked candidate polymer with maximum fluid absorbance capacity. The structure and morphology were confirmed by Fourier transform infrared spectroscopy and scanning electron microscopy. The synthesized hydrogel held a large amount of water and was used as a device for controlled release of urea. A 10 % (w/w) of swelled hydrogel was found to enhance the water-holding capacity of the soil. The synthesized device could increase the moisture content up to 52 % in sandy loam soil and 72 % in clay soil and was found to enhance the water-holding capability of the soil. Further, the candidate polymer was studied for the controlled release of urea under eco-friendly conditions and showed case-II type urea release. The initial diffusion coefficient was found to be higher than the later diffusion coefficient indicating a higher urea release rate during the early stage. Thus, the synthesized polymer is important from technological point of view.

Polysaccharide Hydrogels: Synthesis, Characterization, and Applications

Abstract: This chapter deals with the review on natural backbone-based superabsorbent hydrogels and their classification based upon method of preparation, monomer type, and ionic charge. The applications of hydrogels in different fields like biomedical, pharmaceuticals, agriculture, metal ion sorption, etc., have been discussed in this chapter. The polysaccharide-based hydrogels are eco-friendly, cost effective, biodegradable, and biocompatible in nature. They can be characterized by different techniques like FTIR, SEM, XRD, AFM, TGA, DTA, DTG, and DSC.

Synthesis and optimization of soy protein fiber based graft copolymer through response surface methodology for removal of oil spillage

Abstract: Present study deals with the development of novel biodegradable polymer device for petroleum fraction removal from different petroleum-saline emulsion. Soy protein fiber was graft copolymerized with poly(methylmethacrylate) using sequential experimental design approach. Six process variables, such as solvent amount, monomer concentration, FAS:KPS ratio, reaction time, reaction temperature, and pH were taken at two levels as per Resolution-V design. Significant process variables were monomer concentration, reaction temperature, and pH. In phase-2, screened variables were taken for model building and optimization as per optimal response surface design. At optimum conditions (monomer concentration: 3.10 mmol L−1; reaction temperature: 84.2 °C; pH 6.03), the graft percentage was found to be 272 %. Graft copolymer was characterized using FTIR, SEM, TGA, DTA, and DTG techniques. Further, graft copolymer was evaluated for acid–base and moisture resistance behavior. The synthesized soy protein fiber based polymer showed 76–70 % petroleum fraction absorption from different petroleum-saline emulsions.

In Vacuo Synthesis of Xanthan-gum-based Hydrogels with Different Vinyl Monomer Mixtures and their Swelling Behaviour in Response to External Environmental Conditions

Abstract: This research paper deals with the in vacuo synthesis of pH- and temperature-sensitive hydrogels of xanthan gum with different vinyl monomer mixtures such as acrylamide-co-acrylic acid (AAm-co-AA),

Bioremediation of Natural Fiber by Graft Copolymerization

Abstract: In this research paper, the Sorrel stem fiber was graft copolymerized by vinyl monomeric mixtures that lead to an increase in the percentage grafting with a significant change in physico-chemico-thermal resistance. Miscibility in organic solvents, hydrophobicity was found to increase whereas crystallinity, crystallinity index, dye-uptake and hydrophylicity decreased after graft copolymerization. These graft copolymers were reinforced in polymer matrix (Phenol-Formaldehyde) to procure green composite. These bio-composites were subjected to characterized and evaluated and were found to be advanced material.

Water-Soluble Carbon Nanotubes from Bitumen Waste: Synthesis, Functionalisation and Derivatisation for its Use as Superabsorbent

Abstract: A simple method for the preparation of carbon nanotubes (CNTs) from bitumen waste and their derivatisation with polyacrylamide was achieved. Synthesised CNTs were functionalised in the presence of dilute nitric acid followed by derivatisation with polyacrylamide using the mixture of potassium persulphate-ferrous ammonium sulphate as a redox initiator and N,N′-methylene-bis-acrylamide as a crosslinking agent. The functionalisation and derivatisation of the CNTs were confirmed through Fourier transform infrared spectroscopy, scanning electron microscopy, transmission electron microscopy and X-ray diffraction techniques. The effect of derivatisation on the thermal properties of the CNTs was studied by thermogravimetric analysis, differential thermogravimetric analysis and differential thermal analysis. The crosslinked derivatised product, CNT-cl-poly(AAm), was thermally more stable than the functionalised CNTs. The water-absorption capacity of the derivatised CNTs was investigated in deionised water as a function of time, temperature and pH of the swelling medium. CNT-cl-poly(AAm) was found to be an efficient water-absorption device with the maximum absorption capacity of 476 %.

Evaluation of Sereni Fiber Reinforced Composite

Abstract: Sereni stem fiber, due to low weight and high tensile strength was selected as backbone for graft copolymerization with binary vinyl monomeric mixture to explore its effect on percentage grafting, ...

Evaluation of Physio-chemical and Thermal properties of Soy Protein Concentrate and Different Binary Mixtures Based Graft Copolymers

Abstract: Present investigation deals with the modification of biopolymer to improve physio-chemical and thermal properties. In air synthesis of graft copolymers of soy protein concentrate (SPC) with vinyl monomer mixtures of ethylmethacrylate (EMA) with methylmethacrylate (MMA), methylacrylate (MA) and ethylacrylate (EA) was carried-out using ascorbic acid/ potassium persulphate (AAc/ KPS) redox initiator system. Graft copolymers formed were characterized using techniques like FTIR, SEM and XRD. Initial optimization of different reaction parameters was carried out for graft copolymerization of principal monomer EMA onto soy protein concentrate to get maximum graft yield (134.12%). The maximum graft yields with binary monomer mixtures; EMA+MMA, EMA+EA and EMA+MA were 120.54%, 142.38% and 293.58%, respectively. The graft copolymers were studied for thermal stability and were found to show high thermal stability. Modified protein was found to show improved chemical resistance toward acid and base. Moreover, grafted protein also showed enhanced moisture retardance.

Integrated Methodology for Economic Incentive Materials

Abstract: Nature has gifted mankind with precious resources on earth. A major part of the earth provides us with renewable biomass that mostly degrades with time. Graft copolymerization is a chemical technique to improve the properties of the waste biomass and to modify its properties while sustaining the inherent trait. With the advancement of science and research many efforts have been made to modify the techniques. This review explores a brief overview of this magnificent engineering, its techniques and characterization that has helped to provide with outstanding results for better scientific and industrial achievements.

Synthesis, Characterization and Evaluation of Property Profile of Hybrid Ion- Exchanger

Abstract: Gum tragancanth based organic-inorganic hybrid ion exchanger has been synthesized using a mixture of sodium tungstate, orthophosphoric acid and potassium iodate. The different reaction conditions like reaction temperature, reaction time, pH of reaction medium, solvent volume, monomer concentration and initiator concentration were optimized in order to get the semi-IPN Gt-cl-poly (AA). Onto semi IPN, methylmethacrylate was incorporated using lipase-gluteraldehyde as the initiator-crosslinker system. The IPN finally was converted into ion-exchanger and was studied for its different physico-chemical properties. Ion exchange capacity was studied for Na+ and effect of different temperatures on ion exchange capacity was evaluated. Characterization was done using Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM) and EDS techniques.

The Study of Hibiscus sabdariffa-reinforced-cellulose Fibre Composite

Abstract: Waste biomass, in the form of Hibiscus sabdariffa stem fibre (1cm length), was used as reinforcement in a phenoplast polymer matrix to form a composite. The ratio of phenol in the phenoplast resin was varied whereas formaldehyde was kept constant; a phenol formaldehyde ratio of 0.75:1.0 and fibre:resin ratio of 12.7:87.3 were found to exhibit maximum mechanical strength. The comparative mechanical evaluation of the phenoplast and fibre-reinforced composite was performed by assessment of the hardness, modulus of rupture (MOR), modulus of elasticity (MOE), stress at the limit of proportionality (SP), tensile strength, compressive strength and wear resistance. The composites were characterized using advanced techniques. It was observed that fibre-reinforced phenol-formaldehyde (PF) composites exhibited physico-chemical resistance and improved mechanical behaviour compared with the phenoplast composite.