scholarly journals Chemical and Physical Properties of Cassava Starch–CM-Chitosan–Acrylic Acid Gel Copolymerization by Gamma Irradiation

2014 ◽  
Vol 14 (1) ◽  
pp. 37-42
Author(s):  
Gatot Trimulyadi Rekso

Starch is a renewable natural polymer that can be decomposed easily in the environment and can be modified to various applications such as biomedical, agricultural and pharmaceutical applications. Copolymerization of gelatinized starch–CM-chitosan and acrylic acid (AAc) in aqueous medium using γ-irradiation was carried out. The preparation conditions, such as irradiation dose and AAc concentration were investigated. The copolymers were characterized by FTIR spectroscopy, thermo-gravimetric analysis (TGA) and scanning electron microscopy (SEM). The results show that by increasing of irradiation dose the gel fraction increases till the dose of 15 kGy. Above the stating dose the gel fraction decreases. The Equilibrium Degree of Swelling (EDS) value slightly increases with increasing irradiation dose and after dose of 15 kGy is decreasing. The swelling of starch–CM-chitosan–AAc hydro gels reduced as the gel content increases. The results indicated that the optimum condition for obtaining hydro gels with desirable properties was irradiated at dose of 15 kGy. The results indicated that SEM revealed that the higher the dose, the lower the copolymer pore size. The starch–CM-chitosan–AAc copolymers have thermal stability higher than that for starch individually.

Author(s):  
Gatot Trimulyadi Rekso ◽  
Adjat Sudradjat

The present study aimed to synthesize and evaluate copolymerization of starch-acrylamide by gamma irradiation for hydrogel Copolymerization of gelatinized starch and acrylamide (AAm) in aqueous medium using γ-irradiation was carried out. The preparation conditions, such as irradiation dose and AAm concentration, were investigated. The copolymers were characterized by FTIR spectroscopy, thermo-gravimetric analysis (TGA), and scanning electron microscopy (SEM). The results show that by increasing of irradiation dose, the gel fraction increases till the dose of 15 kGy. Above the stating dose, the gel fraction decreases.  The Equilibrium Degree of Swelling (EDS) value slightly increases with increasing irradiation dose, and after a dose of 15 kGy is decreasing. The swelling of starch- AAm hydrogels reduced as the gel content increases.  The results indicated that the optimum condition for obtaining hydrogels with desirable properties is irradiated at a dose of 15 kGy. The results indicated that SEM revealed that the higher the dose, the lower the copolymer pore size. The starch-AAm copolymers have thermal stability higher than that for starch individually.


2019 ◽  
Vol 6 (10) ◽  
pp. 190690
Author(s):  
Zhongkan Ren ◽  
Christel Gervais ◽  
Gurpreet Singh

Ceramic matrix composite (CMC) materials have been considered a desired solution for lightweight and high-temperature applications. Simultaneously, among all different CMC reinforcements, polymer-derived ceramic (PDC) fibres have gained attention for the intrinsic thermal stability and mechanical strength with simple and cost-effective synthesis techniques. Here, carbon-rich SiOCN fibres were synthesized via hand-drawing and polymer pyrolysis of a hybrid precursor of 1,3,5,7-tetramethyl-1,3,5,7-tetravinylcyclotetrasilazane (TTCSZ) and poly-acrylic acid (PAA). The type of silazane reported in this work is considered as a major precursor for SiCN; however, it is unspinnable, due to its unfavourable physical properties (low viscosity) and chemical structure (cyclic rather than linear structure). The introduction of PAA to TTCSZ to create a hybrid precursor remarkably improved the spinnability of the silazane and should be widely applicable to other unspinnable PDC pre-ceramic polymers. Investigations on the structural and compositional development of the fibres were mainly conducted via Raman spectroscopy, Fourier-transform infrared spectroscopy, scanning electron microscopy, X-ray photoelectron spectroscopy, nuclear magnetic resonance and thermo-gravimetric analysis to determine spinnability, free carbon content, cross-linking and pyrolysis behaviour of the fibres, respectively.


2013 ◽  
Vol 746 ◽  
pp. 88-96 ◽  
Author(s):  
Erizal ◽  
Sudirman ◽  
Emil Budianto ◽  
A. Mahendra ◽  
Rike Yudianti

Sodium alginate (NaAlg) is considered to be a potential natural polymer for biomaterial applications, because of its hydrophilic properties that is capable to increase the swelling of hydrogels and biodegradable. This study describes the synthesis of a poly (acrylamide-co-acrylic acid) NaAlg superabsorbent hydrogels via crosslinking gamma radiation. The effect of irradiation dose (20-40 kGy) and NaAlg concentration (0.1-0.7 %) of on swelling of hydrogels were studied. The copolymers were characterized by Fourier transform infra red spectroscopy (FTIR) and scanning electron microscopy (SEM) micrograph. The presence of the lowest (0.1%) NaAlg concentration provokes a significant increasing the equilibrium degree solution (EDS) of hydrogel up 800 g/g ,and the extent of gel fraction increases as a function irradiation dose up to about 99 %. The hydrogels were also found to be sensitive to the ionic strength of medium. The FTIR spectra of hydrogels were shown crosslinking occurs between acrylamide and acrylic acid and pores structures in the hydrogel observed by using SEM.


2011 ◽  
Vol 29 (No. 6) ◽  
pp. 616-623 ◽  
Author(s):  
A.-J. Zhang ◽  
Q.-L. Qin ◽  
H. Zhang ◽  
H.-T. Wang ◽  
X. Li ◽  
...  

The preparation and characterisation of food-grade chitosan from housefly larvae are reported. A refinement procedure was developed to remove larval mouth hooks from the primary chitosan product, which greatly improved the quality of the final product and simplified the production procedures. Different factors affecting chitosan preparation were studied and an orthogonal experiment was designed to determine optimal preparation conditions. When prepared under optimal reaction conditions, the end product was snow-white in colour, had a high deacetylation percentage, good viscosity, and a low ash content. The end product was characterised by Fourier transform infrared spectral analysis, X-ray diffraction analysis, thermo-gravimetric analysis, and differential scanning calorimetry. Its physical and chemical properties and sanitary index were determined and compared to the relevant Chinese standards. The results show that the chitosan we produced under optimal conditions meets the Chinese Fishery Trade Standard SC/T3403-2004 for food-grade chitosan.


2012 ◽  
Vol 12 (2) ◽  
pp. 113-118 ◽  
Author(s):  
Erizal Erizal

Modification of poly (acrylamide-co-acrylic acid) superabsorbent hydrogels with varying starch concentration (1-3%) via simultaneous gamma radiation have been carried out. The structure and morphology of copolymers were characterization by Fourier transform infra red spectroscopy and scanning electron microscopy. The gel fraction, swelling kinetics and the equilibrium degree of swelling (EDS) of the hydrogels were studied. It was found that the an increase in the starch content present in the hydrogels (1-3%) and with increase irradiation dose  from 10 kGy up to 30 kGy, the swelling ratio decreased from 250-100 g/g. Incorporation of 1% starch increases the EDS of the hydrogels up 350 g/g. Under maximum conditions, poly(AAm-co-AA)-starch hydrogels with high gel fraction (~93%) was prepared from aqueous solution containing 5% AAm, 15% acrylic acid and 0-3% starch. The hydrogels were sensitive against salts solution.


2010 ◽  
Vol 148-149 ◽  
pp. 118-125
Author(s):  
Jia Yu Zeng ◽  
Wei Bo Zhang ◽  
Shi Qi Liao ◽  
Dong Xia Zhang ◽  
Yun Pu Wang ◽  
...  

A polymerization between 1,4-diaminobenzene (PPD) and acrylic acid catalyzed by Horseradish Perodxidase (HRP) in an water buffer will be described in this article. The effects of the concentration of H2O2, the ratio of the acrylic acid to PPD, the pH of the buffer, and the reaction time of polymerization were investigated. Compared with conventional methods, the synthesis is simple and the conditions are mild. The conductivity, UV-vis spectra, FT-IR spectra, X-ray photoelectron spectroscopy (XPS), and the thermo-gravimetric analysis (TGA) of the resulting polymer were investigated also. The results show that the synthesized polymer (PAnI) is a self-doped poly(1,4-diaminobenzene-acrylic acid) with 1,4-disubstituted aromatic ring, and a higher electro-activity, water-solubility, its decomposition temperature is 498.8 °C.


2014 ◽  
Vol 852 ◽  
pp. 304-308
Author(s):  
Guo Liang Dai ◽  
Hong Xiao ◽  
Shi Feng Zhu ◽  
Mei Wu Shi

Electron beam irradiation cross-linking of polyvinyl alcohol (PVA) films with the presence of N, N'- methylene bisacrylamide (MBA) were studied, improving the thermal stability. The films unirradiated and irradiated were characterized by ATR-FTIR spectroscopy, X-ray diffraction, differential scanning calorimetry and thermo gravimetric analysis. The PVA films with the presence of MBA would crosslink after irradiation. The crystallinity increased firstly and then decreased as a function of irradiation dose, while the melting temperature decreased with increasing the dose. Beside, the T30%, T50%, T90% and Tmax temperature of degradation increased as the irradiation dose increased.


2003 ◽  
Vol 775 ◽  
Author(s):  
G.V.Rama Rao ◽  
Qiang Fu ◽  
Linnea K. Ista ◽  
Huifang Xu ◽  
S. Balamurugan ◽  
...  

AbstractThis study details development of hybrid mesoporous materials in which molecular transport through mesopores can be precisely controlled and reversibly modulated. Mesoporous silica materials formed by surfactant templating were modified by surface initiated atom transfer radical polymerization of poly(N-isopropyl acrylamide) (PNIPAAm) a stimuli responsive polymer (SRP) within the porous network. Thermo gravimetric analysis and FTIR spectroscopy were used to confirm the presence of PNIPAAm on the silica surface. Nitrogen porosimetry, transmission electron microscopy and X-ray diffraction analyses confirmed that polymerization occurred uniformly within the porous network. Uptake and release of fluorescent dyes from the particles was monitored by spectrofluorimetry and scanning laser confocal microscopy. Results suggest that the presence of PNIPAAm, a SRP, in the porous network can be used to modulate the transport of aqueous solutes. At low temperature, (e.g., room temperature) the PNIPAAm is hydrated and extended and inhibits transport of analytes; at higher temperatures (e.g., 50°C) it is hydrophobic and is collapsed within the pore network, thus allowing solute diffusion into or out of the mesoporous silica. The transition form hydrophilic to hydrophobic state on polymer grafted mesoporous membranes was determined by contact angle measurements. This work has implications for the development of materials for the selective control of transport of molecular solutes in a variety of applications.


2008 ◽  
Vol 59 (7) ◽  
Author(s):  
Madalina Angelusiu ◽  
Maria Negoiu ◽  
Stefania-Felicia Barbuceanu ◽  
Tudor Rosu

The paper presents the synthesis and characterization of Cu(II), Co(II), Ni(II), Cd(II), Zn(II) and Hg(II) complexes with N1-[4-(4-bromo-phenylsulfonyl)-benzoyl]-N4-(4-methoxyphenyl)-thiosemicarbazide. The new compounds were characterized by IR, EPR, electronic spectroscopy, magnetic moments, thermo-gravimetric analysis and elemental analysis.


2020 ◽  
Vol 13 ◽  
Author(s):  
Inbasekaran S. ◽  
G. Thiyagarajan ◽  
Ramesh C. Panda ◽  
S. Sankar

Background:: Chrome shavings, a bioactive material, are generated from tannery as waste material. These chrome shaving can be used for the preparation of many value-added products. Objective:: One such attempt is made to use these chrome shaving wastes as a composite bio-battery to produce DC voltage, an alternate green energy source and cleaner technology. Methods:: Chrome shavings are hydrolyzed to make collagen paste and mixed with the ferrous nanoparticles of Moringa oleifera leaves and Carbon nanoparticles of Onion peels to form electrolyte paste as base. Then, the electrolyte base was added to the aluminum paste and conducting gel, and mixed well to form composite material for bio-battery. Results:: The composite material of bio-battery has been characterized using Scanning Electron Microscopy (SEM), Fourier-Transform Infrared Spectroscopy (FTIR), Differential Scanning Calorimetry (DSC) and Thermo Gravimetric Analysis (TGA). Series and parallel circuit testing were done using Copper and Zinc electrodes or Carbon and Zinc electrodes as the battery terminals in the electrolyte paste. The surface area of these electrodes needs standardization from bench to pilot scale. The power generated, for an AA battery size, using a single bio-battery cell has produced a DC voltage of 1.5 V; current of 900 mA. Circuit testing on 1 ml of 80 well-cells connected in series has produced DC output of 18 V and 1100 mA whereas 48 V and 1500 mA were obtained from a series-parallel connection. Conclusion:: The glass transition temperature (Tg) of electrolyte of the bio-battery at 53°C indicates that, at this temperature, all the substances present in the bio-battery are well spread and contributing consistently to the electrolyte activity where Fe-C-Nano-Particles were able to form strong chemical bonds on the flanking hydroxyl group sites of the Collagen leading to reduced mobility of polymers and increase Tg. The results instigate promising trends for commercial exploitation of this composite for bio-battery production.


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