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Editor's Choice : 5-Hydroxy-6-Methyluracil as a Polyvinyl Chloride Stabilizer
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Abstract: Kinetic regularities of thermooxidative dehydrochlorination of rigid and plasticized PVC in the presence of 5-hydroxy-6-methyluracil have been studied. The high antioxidant efficacy of 5-hydroxy-6-methyluracil in the process of polymer degradation has been revealed. It is shown that the studied uracil significantly slows down the process of accumulation of hydroperoxides in oxidation of dioctyl phthalate the plasticizer of PVC, which is the cause of a significant slowdown in the rate of decomposition of the plasticized polymer. Keywords: Polyvinyl chloride, thermooxidative dehydrochlorination, antioxidant, 5-hydroxy-6-methyluracil, low toxicity.Download Full Article |
Editor's Choice : Carboxylated Magnetite Composite Polymer Nanoparticles with Mosaic Structure for Biomedical Application
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Abstract: In this article, a microemulsion method for preparation of magnetite composite polymer nanoparticles of Fe3O4@poly(styrene-methacrylic acid) (MNP@PSMA) crosslinked with1,6-hexanediol diacrylate (HDD) insitu with carboxyl functionality on the surface has been reported. Structure and morphology of the nanoparticles was studied by Fourier Transform Infrared spctroscopy (FTIR), X ray Diffraction (XRD), Thermal Gravimetric Analyser (TGA), Vibrating Sample Magnetometer (VSM) and Transmission Electron Microscopy (TEM). VSM studies confirmed saturation magnetization of 20.0 emu/g in an external magnetic field. Nanoparticles formed were of 30 nm in diameter with narrow size distribution and mosaic structure providing a large surface area useful for application in bioseparation. Experimental results of covalent coupling of composite nanoparticles indicated maximum protein binding capacity of 350 mg bovine serum albumin (BSA) per gram. Keywords: Microemulsion, magnetic nanoparticle supports, protein separation.Download Full Article |
Editor's Choice : A Brief Overview on Ferrite (Fe3O4) Based Polymeric Nanocomposites: Recent Developments and Challenges
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Abstract: In this article, we have mainly discussed about ferrite (Fe3O4)and its polymer based nanocomposites. Ferrite particles have become an important research material because of their vast applications in the field of biotechnology, magnetic resonance imaging (MRI), and data storage.It has been observed that ferrite Fe3O4particles show best performance for size less than 10-30 nm. This happens due to the super paramagnetic nature of such particles. In super paramagnetic range these particles exhibit zero remanence or coercivity. Therefore, various properties of ferrite (Fe3O4) nanoparticlesand its polymer nanocomposites are very much dependent on the size, and distribution of the particles in the polymeric matrix. Moreover, it has been also observed that the shape of the nanocrystals plays important role in the determination of their fundamental properties. These particles show instability over longer times due to the formation of agglomerates generated by high surface energies. Therefore, protection strategies such as grafting and coatings with silica/carbon or polymers have been developed to stabilize them chemically. Recently, silylation technique is mainly used for the modification of nanoparticles. Experimentally, it has been observed that nanocomposites composed ofpolymer matrices and ferriteshowed substantial improvements in stiffness, fracture toughness, sensing ability (magnetic as well as electric), impact energy absorption,and electro-catalytic activities to bio-species. Keywords: Optoelectronic, Ferroelectric, Piezeoelectric, Superparamagnetic, Nanocomposites.Download Full Article |
Editor's Choice : Characterization of Phosphate Glass Reinforced Gelatin Blend Bioactive Composite Films
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Abstract: Bioactive composite films were prepared using bioresorbable phosphate glass powder and biodegradable polymer gelatin (G) through solution casting process. Biocompatible monomer, 2-hydroxyethyl methacrylate (HEMA) was used as the cross-linking agent and bioresorbable phosphate glass (PG) powder was used as reinforcement filler. The composite films were obtained at various ratios of G, PG and HEMA. The PG modified gelatin composite (PG/G) film was fabricated at a weight ratio of 12:88 while HEMA modified gelatin composite (HEMA/G) film at 50:50 ratio. On the other hand, hybrid gelatin composite film, containing both PG and HEMA, was obtained using a G/PG/HEMA ratio of 44:12:44. Incorporation of PG improved the mechanical properties of the composite films. Morphological property of the composite films was investigated by stereo microscope and it revealed that the composite films were porous in nature. The thermal behaviour of the films was studied using thermogravimetric analysis. Water uptake of the films was also performed. Keywords: Gelatin, phosphate glass, bioactive, composite films, stereo microscope.Download Full Article |
