scholarly journals Functional polyketones for the removal of calcium and magnesium from water (Part II): cross-linking and functional characterization

2017 ◽  
Vol 89 (1) ◽  
pp. 51-60 ◽  
Author(s):  
Patrick A. Figaroa ◽  
Henk Miedema ◽  
Gert-Jan Euverink ◽  
Francesco Picchioni

AbstractFunctional polyketones were chemically cross-linked for the softening of hard water, i.e. for the removal of the divalent cations Ca2+ and Mg2+. Elemental analysis, FT-IR spectroscopy, solubility- and swelling-experiments were used to demonstrate the occurrence of the cross-link reaction. Testing the different compounds for their Ca2+ and Mg2+ removal capacity assessed the structure-functionality of the polymers. The corresponding water-insoluble resins were then tested for their Ca2+ and Mg2+ removal capacity-performance being explained in terms of their chemical structure. Ion adsorption of these polymers is not based on an ion exchange, the prevailing mechanism for most currently existing adsorption resins. Rather, the amino functionalized polymers synthesized here adsorb cations as well as their accompanying anionic counterparts, possibly through a chelating mechanism. The obtained results show that functional polyketones are promising in this context as they are easily tunable with the chemical nature of the N-containing groups determining the affinity of the polymer for Ca2+ and/or Mg2+.

2011 ◽  
Vol 236-238 ◽  
pp. 2045-2052 ◽  
Author(s):  
Qiao Wang ◽  
Jian Wang ◽  
Geng Zhong

Amorphophallus bulbifer (A. bulbifer) is a promising species in Amorphophallus sp., with great potentiality of developing, low risk for cultivation and considerable commercial benefits, mainly locates in tropical and subtropical regions or near the equator. Konjac glucomannan (KGM) is the main component of Amorphophallus tuber which is a water-soluble dietary fiber. In this work, some physiochemical properties of KGM in three Amorphophallus species flour [one was A.bulbifer, the other two were current main species namely Amorphophallus rivieri (A. rivieri) and Amorphophallus albus (A. albus)] were studied and compared with each other. The KGM content in A. rivieri, A. albus and A. bulbifer flour were 85.03%, 76.28% and 88.07% (w/w), respectively. The apparent viscosity, viscosity average molecular weight, whiteness, gel-forming properties and chemical structure of KGM in the three flours were investigated by using viscometer, colorimeter, texture analyzer and Fourier transform infrared (FT-IR) spectroscopy. The results indicated that the viscosity and Mw of A. bulbifer was the largest, gel strength was almost same (p>0.05) and the molecular structure were of no differences of three KGM. It may be proposed that transplanting A. bulbifer from its native land in the tropical and subtropical regions to temperate zone in the southwest part of China would be feasible, and it would cause the revolution of Amorphophallus sp. and more considerable benefits.


2018 ◽  
Vol 156 ◽  
pp. 05006 ◽  
Author(s):  
Aji Prasetyaningrum ◽  
Bakti Jos ◽  
Yudhy Dharmawan ◽  
Ratih V. Octaviani ◽  
Ratnawati Ratnawati

Kappa (κ-) carrageenan oligomers are known to have several biological activities. Recent progress in the development of modified κ-carrageenan has resulted low molecular of κ-carrageenan. Ozone is a powerful oxidant and considered for depolymerization of κ-carrageenan. However, few studies have investigated the changes in κ-carrageenan properties associated with ozone treatment. This study would investigate on the changes in chemical structure after ozonation process. The experiments were carried out in a glass reactor equipped with an ozone bubble diffuser. Ozone with concentration of 80 ± 2 was bubbled into the solution. The ozone treatment was conducted at different times, i.e., 0 (control), 5, 10, 15, and 20 minutes. The experiments were conducted at pH 7 and constant stirring speed (200 rpm). Ozone-treated κ-carrageenan was dried at 60 ºC for 24 h in a forced air oven. The chemical and spectral analyses of κ-carrageenan after ozonation process were carried out using UV-Vis and FT-IR spectroscopy. These changes are seen in the UV spectra as a high intensity of absorbance peak at 290 nm. It is shows that ozonation of κ-carrageenan leads to some chemical changes such as the formation of carbonyl, carboxyl or double bonds.The FT-IR spectra reveals that the chemical structure of degraded κ-carrageenan, in term of sulfate content, is only slightly affected by the ozone treatment.


Author(s):  
B. Sangeetha ◽  
A. S. Krishnamoorthy ◽  
D. Amirtham ◽  
D. Jeya Sundara Sharmila ◽  
P. Renukadevi ◽  
...  

Ganoderma lucidum is an important medicinal mushroom widely used in pharmaceuticals for their antiviral, antibacterial, antifungal, anticancer and immunoregulatory properties and also used in agriculture as an antiviral and antibacterial agent. Fourier Transform Infrared (FT-IR) spectroscopy is a tool widely used in the researches for the identification of organic compounds in the organism. In our study, we used FT-IR Spectroscopy for determination the chemical nature of Ganoderma lucidum, and their standards Squalene and Ganoderic acid A. In the FT-IR spectrum for the G. lucidum obtained in the region of 3782.69 cm-1 to 568.898 cm-1 the absorptions peak represents the alcohols, halogens, silicon and phosphorus groups present in the sample. In the squalene standard, ketones, amides, and guanidine, nitrile and azine stretches were found in the wavelength 1655-1550 cm-1. In the Ganoderic acid A sulfur compounds with weak stretching intensity were obtained in the wavelength 500-400 cm-1. We have concluded that FT-IR spectroscopy is an effective method to analyze the chemical nature of the organic groups present in the samples.


2018 ◽  
Vol 36 (1) ◽  
pp. 102-106 ◽  
Author(s):  
Afarin Bahrami ◽  
Kasra Behzad ◽  
Nastaran Faraji ◽  
Alireza Kharazmi

Abstract This work presents the synthesis of PANI-PVA-ZnS nanocomposite films by gamma irradiation approach. The samples were irradiated with different doses ranging from 10 kGy to 40 kGy. Subsequently, structural, morphological, optical and electrical characteristics of the samples were investigated. Fourier transform infrared (FT-IR) spectroscopy was employed to study the chemical structure of the samples. Field emission scanning electron microscopy (FE-SEM) was used to investigate the morphology of nanocomposites. The electronic absorption characteristics of the samples were measured by means of UV-Vis spectroscopy. The AC and DC electrical behaviors of the samples were characterized using LCR meter in the frequency range of 20 Hz to 1 MHz. The impedance values of the samples were extracted from Cole-Cole plots and consequently DC conductivity was calculated.


2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Xiao-Feng Sun ◽  
Yang Feng ◽  
Xiaodi Shi ◽  
Yaxiong Wang

Xylan/poly(methacrylic acid) semi-interpenetrating network hydrogels were synthesized, and these hydrogels were fabricated using various ratios of xylan and methacrylic acid and cross-linked by N,N′-methylenebisacrylamide. The chemical structure and morphology of the prepared hydrogels were characterized by FT-IR spectroscopy and SEM analysis. The porous structure of the prepared hydrogels was found, and the interconnected porous channels increased when the content of xylan was increased in the hydrogels. The hydrogels presented excellent pH sensitivity and swelling reversibility. The dynamic swelling kinetics were also studied, and all obtained results indicated that the prepared xylan/poly(methacrylic acid) semi-IPN hydrogel could be used in biomedical fields, especially for drug release.


2020 ◽  
Vol 17 (10) ◽  
pp. 760-771
Author(s):  
Qirui Gong ◽  
Niangui Wang ◽  
Kaibo Zhang ◽  
Shizhao Huang ◽  
Yuhan Wang

A phosphaphenanthrene groups containing soybean oil based polyol (DSBP) was synthesized by epoxidized soybean oil (ESO) and 9,10-dihydro-oxa-10-phosphaphenanthrene-10-oxide (DOPO). Soybean oil based polyol (HSBP) was synthesized by ESO and H2O. The chemical structure of DSBP and HSBP were characterized with FT-IR and 1H NMR. The corresponding rigid polyurethane foams (RPUFs) were prepared by mixing DSBP with HSBP. The results revealed apparent density and compression strength of RPUFs decreased with increasing the DSBP content. The cell structure of RPUFs was examined by scanning electron microscope (SEM) which displayed the cells as spherical or polyhedral. The thermal degradation and flame retardancy of RPUFs were investigated by thermogravimetric analysis, limiting oxygen index (LOI), and UL 94 vertical burning test. The degradation activation energy (Ea) of first degradation stage reduced from 80.05 kJ/mol to 37.84 kJ/mol with 80 wt% DSBP. The RUPF with 80 wt% DSBP achieved UL94 V-0 rating and LOI 28.3. The results showed that the flame retardant effect was mainly in both gas phase and condensed phase.


Materials ◽  
2019 ◽  
Vol 13 (1) ◽  
pp. 127 ◽  
Author(s):  
Yu Sun ◽  
Yazhen Wang ◽  
Li Liu ◽  
Tianyuan Xiao

A 9,10-dihydro-9-oxa-10-phosphaphenanthrene 10-oxide (DOPO) acrylate, (6-oxidodibenzo [c,e][1,2] oxaphosphinin-6-yl) methyl acrylate (DOPOAA), has been prepared. Copolymers of styrene (St) and DOPOAA were prepared by emulsion polymerization. The chemical structures of copolymers containing levels of DOPOAA were verified using Fourier transform infrared (FT-IR) spectroscopy and 1H nuclear magnetic resonance (1H-NMR) spectroscopy. The thermal properties and flame-retardant behaviors of DOPO-containing monomers and copolymers were observed using thermogravimetric analysis and micro calorimetry tests. From thermogravimetric analysis (TGA), it was found out that the T5% for decomposition of the copolymer was lower than that of polystyrene (PS), but the residue at 700 °C was higher than that of PS. The results from micro calorimetry (MCC) tests indicated that the rate for the heat release of the copolymer combustion was lower than that for PS. The limiting oxygen index (LOI) for combustion of the copolymer rose with increasing levels of DOPOAA. These data indicate that copolymerization of the phosphorus-containing flame-retardant monomer, DOPOAA, into a PS segment can effectively improve the thermal stability and flame retardancy of the copolymer.


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