Mithu Maiti

Graft Copolymerization of Methylmethacrylate onto Acetylated Saccharum spontaneum L. Using FAS-KPS as a Redox Initiator and Evaluation of Physical, Chemical, and Thermal Properties

Abstract The present work deals with morphological modifications and physicochemical properties of acetylated Saccharum spontaneum L. through graft copolymerization with methyl methacrylate (MMA) using ferrous ammonium sulfate-potassium persulfate (FAS-KPS) redox initiator. Different reaction parameters such as reaction temperature, time, initiator molar ratio, monomer concentration, pH, and solvent were optimized to get maximum graft yield (152%). The acetylated S. spontaneum L. and its graft copolymer were characterized by FT-IR, SEM, XRD, TGA, DTA, and DTG techniques. Acetylated S. spontaneum L. and its graft copolymer have been found to show higher moisture and chemical resistance.

Rapid Synthesis of Graft Copolymer of MMA Onto Saccharum spontaneum L. Under Microwave Irradiation for Enhanced Thermal Modifications

Abstract In this article, synthesis of graft copolymers of methyl methacrylate (MMA) onto Saccharum spontaneum L. fiber under the influence of microwave radiation (MWR) was carried out. Different reaction parameters such as time, initiator molar ratio, monomer concentrations, microwave power, pH, and solvent were optimized for maximum graft yield (62.3%). The graft copolymers thus formed were characterized by FT-IR, SEM, XRD, and TGA, DTA, and DTG techniques. Moreover, graft copolymers have been found to be more moisture resistant and also showed higher chemical and thermal resistance.

Effect of cross linking of PVA/starch and reinforcement of modified barley husk on the properties of composite films.

Barley husk (BH) was graft copolymerized by palmitic acid. The crystalline behavior of BH decreased after grafting. Poly vinyl alcohol (PVA)/starch (St) blend film, urea formaldehyde cross linked PVA/St films and composite films containing natural BH, grafted BH were prepared separately. The effect of urea/starch ratio, content of BH and grafted BH on the mechanical properties, water uptake (%), and biodegradability of the composite films was observed. With increase in urea: starch ratio from 0 to 0.5 in the blend, tensile strength of cross linked film increased by 40.23% compared to the PVA/St film. However, in grafted BH composite film, the tensile strength increased by 72.4% than PVA/St film. The degradation rate of natural BH composite film was faster than PVA/St film. Various films were characterized by SEM, FT-IR and thermal analysis.

Chitosan-assisted immobilization of serratiopeptidase on magnetic nanoparticles, characterization and its target delivery

Abstract Background: Magnetic nanoparticles (MNPs) gained attentions as universal carrier for drug delivery and for enzyme immobilization. Purpose: Target delivery of serratiopeptidase for treatment using this enzyme and applications in drug delivery. Method: Serratiopeptidase was immobilized on chitosan amino-functionalized MNPs by covalent bonding through glutaraldehyde. Targeting of MNPs with immobilized enzyme (EMNPs) was carried out in vitro in modified diffusion cell and in vivo in rats. Results and discussion: MNPs and EMNPs were 15.43 ± 5.22 and 18.43 ± 3.23 nm (transmission electron microscopy), crystallite size 16.89 and 21.05 nm (X-ray diffraction) and saturation magnetization 62 and 35.2 emug−1, respectively. Maximum protein and enzyme loading on EMNPs were 264 mg g−1 and 325 U g−1, respectively. In the molecular level, maximum 52 enzyme molecules could bind to each particle showing residual activity 68%, little effect on KM and Vmax, good storage stability. Magnetic targeting of EMNPs increased the delivery (permeation) of drug through membrane in vitro and the enhanced anti-inflammatory effect on carrageenan-induced paw oedema in rats in vivo at much lower doses of enzyme than the doses required for treatment with free enzyme. Conclusions: The enzymatic preparation of MNPs showed enhanced effects (permeation enhancement and anti-inflammatory activity) at lower concentration with magnetic targeting.

Induction of Physico-Chemical and Thermal Resistance on Saccharum spontaneum L by Grafting Under Microwave Irradiation

Grafting of methylmethacrylate (MMA) with acrylamide (AAm), acrylonitrile (AN), and acrylic acid (AA) in binary mixtures onto Saccharum spontaneum L (Ss), was carried out under microwave radiation (MW). The maximum graft yield (88.9%) was found with AAm binary mixture. Synthesized graft co-polymers were characterized with FT-IR, scanning electron microscopy (SEM), TGA/DTA/DTG, and X-ray diffraction (XRD) techniques. Thermal stability of Ss-g-poly(MMA+AAm) was found to be higher than that of S. spontaneum fiber and other graft co-polymers. Percentage crystallinity and crystallinity index decreased (85.32 − 77.11 and 0.82 − 0.70, respectively) after grafting but graft copolymers exhibited more moisture, chemical and thermal resistance.

Synthesis and characterization of novel reduced Gum rosin-acrylamide copolymer-based nanogel and their investigation for antibacterial activity

In the present work, we have prepared the iron oxide nanoparticles with and without surfactant and characterized by FTIR, SEM, TEM, XRD, and VSM. The presynthesized nanoparticles were embedded in the Gum rosin-acrylamide copolymer matrix. Polymer matrix which is basically a hydrogel was prepared by a free radical mechanism using potassium persulphate (KPS) and N,N′ methylene-bisacrylamide (MBA) as an initiator-crosslinker system. The synthesized conditions of hydrogel, such as time, temperature, pH, amount of solvent, concentration of monomer, and crosslinker, were optimized to obtain the product with maximum percentages swelling (404%). The nanogels were prepared under vacuum condition. The synthesized GrA-cl-poly(AAm)-Fe2O3 nanogel has been characterized by XRD, FTIR, and SEM techniques for structural. Thermal studies have been done through by TGA/DTA/DTG techniques. The antibacterial activity of the nanocomposites was evaluated against Gram-positive bacteria (Staphylococcus aureus) and Gram-negative (Escherichia coli) using well diffusion method.

Synthesis of Graft Copolymers for Green Composite Films and Optimization of Reaction Parameters using Taguchi (L16) Orthogonal Array

Abstract Oleic acid was graft copolymerized onto barley husk (BH) using a redox initiator. Samples of natural and grafted BH were characterized by fourier transform infrared spectroscopy, scanning electron microscopy (SEM), x-ray diffraction, thermal analysis, swelling (%) and moisture absorption (%). SEM analysis revealed that the surface of the BH became rough after grafting. Reaction time, temperature, amount of solvent, monomer concentration and initiator molar ratio were optimized using conventional as well as Taguchi L16 (orthogonal array) design to get maximum percentage graft yield. At optimized conditions, the maximum graft yield was 55.3% by conventional method, whereas it was 56.82% by Taguchi method. Analysis of variance revealed that the reaction temperature and reaction time were the most and the least influential factors, respectively. Swelling (%) and moisture absorption (%) decreased with the increase in percentage graft yield. Grafted BH showed more chemical and thermal resistance as compared to natural BH. Synthesized graft copolymers were used as reinforcing material in poly vinyl alcohol composite films and rendered higher mechanical properties.

Environment Benevolent Biodegradable Polymers: Synthesis, Biodegradability, and Applications

The increasing amount of synthetic polymers above the permissible limits is causing a lot of environmental pollution and is one of the greatest threats to the modern world. There is a growing demand for biodegradable polymeric materials derived from nature and is being seen as a solution for solid waste management. Biodegradable materials have been found to show a pronounced impact in case of environmental protection. Such biodegradable and eco-friendly materials have got diversified applications including sustained drug delivery devices, gene therapy, soft-tissue engineering, biomedical engineering, pharmaceuticals, artificial organ design, etc. Biodegradable materials have been found to possess good elasticity and impact strength because of which they have got potential applications in replacement of heart valves and kidneys. Moreover, such materials have been found to exhibit selective absorption toward saline water and are of great importance in petroleum industry as well as in desalination of water. Recently, such materials have been found to show electrical stimulus sensitivity both under the influence of AC and DC. These polymers have been found to be stimuli responsive and could be of great significance for drug and pesticide/fungicide delivery devices. Such materials are also pH sensitive toward different media and are of potential industrial usage in packaging and nursery plantation as well as in tissue culturing.

Corrigendum to “Characterization and evaluation of methylmethacrylate-acetylated Saccharum spontaneum L. graft copolymers prepared under microwave’’ [Carbohydr. Polym. 78/4 (November (17)) (2009) 987–996]

Please cite this article in press as: Kaith, B. S., et al. Corrigendum to “Characterization and evaluation of methylmethacrylate-acetylated Saccharum spontaneum L. graft copolymers prepared under microwave” [Carbohydr. Polym. 78/4 (November (17)) (2009) 987–996]. Carbohydrate Polymers (2016), http://dx.doi.org/10.1016/j.carbpol.2016.08.071 n Graft Copolymerization of Methylmethacrylate onto Acetylated Saccharum spontaneum L. Using FAS-KPS as a Redox Initiator and valuation of Physical, Chemical, and Thermal Properties, International Journal of Polymer Anal. Charact., 14: 210–230, 2009., without roper attribution. The publisher would like to apologize to readers for any inconvenience caused.