scholarly journals Structure and Physicochemical Properties of Malate Starches from Corn, Potato, and Wrinkled Pea Starches

Polymers ◽  
2019 ◽  
Vol 11 (9) ◽  
pp. 1523 ◽  
Author(s):  
Miaomiao Shi ◽  
Yue Jing ◽  
Liuzhi Yang ◽  
Xianqing Huang ◽  
Hongwei Wang ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Treatment Time ◽  
Degree Of Substitution ◽  
Degree Of Crystallinity ◽  
Esterification Reaction ◽  
Maximum Heat ◽  
Heat Loss Rate ◽  
Granule Morphology ◽  
Ft Ir ◽  
New Applications

In this study, corn, potato, and wrinkled pea starches were esterified with malic acid under high temperatures for different lengths of time. The degree of substitution (DS), granule morphology, crystal structure, gelatinization properties, and the digestibility of the malate starch were investigated. Fourier transform infrared spectroscopy (FT–IR) suggested that the malate starch showed a new infrared absorption peak near 1747 cm−1, indicating the occurrence of an esterification reaction. With an increasing treatment time, the degree of substitution (DS) of the malate starch displayed an increasing trend. Scanning electron microscopy (SEM) demonstrated a significant change in the surface structure of the starch granules. X-ray diffractometry (XRD) reflected that the crystal structure of the malate starches was destroyed. The thermogravimetric (TG) curves showed that the maximum heat loss rate of the malate starch was ahead of that of native starch, which caused the decreased degree of crystallinity. These properties of malate starch could allow it to be used for the purpose of starch modification to produce resistant starch and to provide new applications for starch.

Effect of Ultrasonic Field on Synthesis and Characterization of Starch Acetate

2012 ◽  
Vol 550-553 ◽  
pp. 865-872
Author(s):  
Xian Liang Song ◽  
Min Zeng ◽  
Bao Yue Zhang ◽  
Jing Wen Chen ◽  
Sheng Ying Ye ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Reaction Time ◽  
Infrared Spectrum ◽  
Ultrasonic Field ◽  
Degree Of Substitution ◽  
Degree Of Crystallinity ◽  
Ultrasound Wave ◽  
Ultrasonic Power ◽  
Starch Acetate ◽  
Ultrasound Waves

The synthesis of corn starch acetate made by traditional chemical modification technology of starch in continuous ultrasonic field was investigated in this experiment. This study mainly focuses on the effects of ultrasound wave power, frequency, reaction time and amount of reactants on degree of substitution of starch acetate. The structure of the product was characterized by scanning electronic microscope(SEM), polarizing microscope, X-ray diffraction and infrared spectrum. The results show that the degree of substitution(DS) of the product is influenced by the power and frequency of ultrasound waves, the reaction time and the amount of reactants. The effect of the ultrasonic power is the most significant. The optimal condition was power 250W, frequency 60kHz, reaction time 75min and the amount of esterifying agent 20ml. The degree of substitution of the starch acetate under such conditions was 0.1043. The appearances and crystal structure of the synthetic starch acetate particles changed under the effect of ultrasonic field. There were concavities and cracks on the surface of the particles and the crystal structure were damaged resulting in lower degree of crystallinity. Infrared spectrum analysis showed that although acetyl groups are introduced into the molecules of starch , the basic structure of the starch molecules were not affected by the ultrasound waves.

Structural, Thermal and Electrical Properties of Doped Poly(3,4 ethylenedioxythiophene)

2016 ◽  
Vol 10 (4) ◽  
pp. 395-400 ◽  
Author(s):  
Deepali Kelkar ◽  
◽  
Ashish Chourasia ◽  
◽  
Keyword(s):  
Crystal Structure ◽  
Electrical Properties ◽  
Xrd Analysis ◽  
Structure Modification ◽  
Camphorsulfonic Acid ◽  
Thermal And Electrical Properties ◽  
Ft Ir

Poly(3,4-ethylenedioxythiophene) (PEDOT) was chemically synthesized, undoped and then re-doped using FeCl3 as well as camphorsulfonic acid (CSA). FT-IR results confirm the nature of the synthesized and doped samples. XRD analysis indicates crystal structure modification after doping and was also used to calculate crystallinity of samples. Crystallinity increases after FeCl3 doping, whereas it reduces due to CSA doping. TGA-DTA results show reduction in Tg value for FeCl3 doped sample while it increases for CSA doped samples compared to that of undoped PEDOT. Reduction in Tg indicates plasticizing effect of FeCl3 whereas increase in Tg show anti-plasticizing effect of CSA in PEDOT. Conductivity value () increases by two orders of magnitude after doping. Log vs. 1/T graph show metallic nature of undoped PEDOT above 308 K, however both doped samples show semiconducting nature from 301 to 383 K.

scholarly journals Polyurethane Composite Foams Synthesized Using Bio-Polyols and Cellulose Filler

Materials ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3474
Author(s):  
Katarzyna Uram ◽  
Milena Leszczyńska ◽  
Aleksander Prociak ◽  
Anna Czajka ◽  
Michał Gloc ◽  
...  
Keyword(s):  
Cross Sections ◽  
Raw Materials ◽  
Polyurethane Foams ◽  
Degree Of Crystallinity ◽  
X Ray Diffraction ◽  
Polyurethane Composite ◽  
Composite Foams ◽  
Closed Cell ◽  
Ft Ir ◽  
The Fourier Transform

Rigid polyurethane foams were obtained using two types of renewable raw materials: bio-polyols and a cellulose filler (ARBOCEL® P 4000 X, JRS Rettenmaier, Rosenberg, Germany). A polyurethane system containing 40 wt.% of rapeseed oil-based polyols was modified with the cellulose filler in amounts of 1, 2, and 3 php (per hundred polyols). The cellulose was incorporated into the polyol premix as filler dispersion in a petrochemical polyol made using calenders. The cellulose filler was examined in terms of the degree of crystallinity using the powder X-ray diffraction PXRD -and the presence of bonds by means of the fourier transform infrared spectroscopy FT-IR. It was found that the addition of the cellulose filler increased the number of cells in the foams in both cross-sections—parallel and perpendicular to the direction of the foam growth—while reducing the sizes of those cells. Additionally, the foams had closed cell contents of more than 90% and initial thermal conductivity coefficients of 24.8 mW/m∙K. The insulation materials were dimensionally stable, especially at temperatures close to 0 °C, which qualifies them for use as insulation at low temperatures.

1H-NMR Analysis of Degree of Substitution in N,O-Carboxymethyl Chitosans from Various Chitosan Sources and Types

2012 ◽  
Vol 506 ◽  
pp. 158-161 ◽  
Author(s):  
A. Jaidee ◽  
Pornchai Rachtanapun ◽  
S. Luangkamin
Keyword(s):  
Chemical Structure ◽  
Carboxymethyl Chitosan ◽  
Degree Of Substitution ◽  
Resonance Spectroscopy ◽  
Nmr Analysis ◽  
Reaction Conditions ◽  
H Nmr ◽  
Fourier Transformed Infrared Spectroscopy ◽  
Chitosan Oligomer ◽  
Ft Ir

N,O-Carboxymethyl chitosans were synthesized by the reaction between shrimp, crab and squid chitosans with monochloroacetic acid under basic conditions at 50°C. The mole ratio of reactants was obtained from various reaction conditions of shrimp chitosan polymer and oligomer types. The mole ratio 1:12:6 of chitosan:sodium hydroxide:monochloroacetic acid was used for preparing carboxymethyl of chitosan polymer types while carboxymethyl of chitosan oligomer types were used the mole ratio 1:6:3 of chitosan:sodium hydroxide:monochloroacetic acid. The chemical structure was analyzed by fourier transformed infrared spectroscopy (FT-IR) and proton nuclear magnatic resonance spectroscopy (1H-NMR). The FT-IR was used for confirm the insertion of carboxymethyl group on chitosan molecules. The 1H-NMR was used for determining the degree of substitution (DS) of carboxymethylation at hydroxyl and amino sites of chitosans. Carboxymethyl chitosan samples had the total DS of carboxymethylation ranging from 1.0-2.2. The highest of DS of carboxymethylation was from shrimp chitosan oligomer type.

scholarly journals Chitosan and Carboxymethyl Chitosan from Fish Scales of Labeo rohita

2013 ◽  
Vol 61 (1) ◽  
pp. 145-148 ◽  
Author(s):  
Tanvir Muslim ◽  
Mohammad Habibur Rahman ◽  
HOsne Ara Begum ◽  
Md. Azizur Rahman
Keyword(s):  
Molecular Weight ◽  
Spectral Analysis ◽  
Labeo Rohita ◽  
Carboxymethyl Chitosan ◽  
Degree Of Substitution ◽  
Monochloroacetic Acid ◽  
Fish Scales ◽  
Ft Ir

Chitin was extracted from the fish scales of Labeo rohita and chitosan was successfully prepared from it by deacetylation reaction. The prepared chtiosan was characterized by FT-IR spectral analysis and degree of decetylation was determined by pH-metric titration. The molecular weight of chitosan was estimated by viscometric method. Chitosan was converted into its carboxymethyl derivative using alkali and monochloroacetic acid. The prepared carboxymethyl chitosan was characterized by FT-IR spectral analysis and degree of substitution was estimated. Dhaka Univ. J. Sci. 61(1): 145-148, 2013 (January) DOI: http://dx.doi.org/10.3329/dujs.v61i1.15116

Effects of the Different Crystallization Time on Synthesis of Zeolite 4A from by-Products of Polysilicon Production Process

2011 ◽  
Vol 347-353 ◽  
pp. 246-251
Author(s):  
Xing Yong Liu ◽  
Min Li ◽  
Hong Chen ◽  
Wei Wei
Keyword(s):  
Production Process ◽  
Degree Of Crystallinity ◽  
Crystallization Time ◽  
Crystallinity Degree ◽  
Structure Morphology ◽  
Zeolite 4A ◽  
Single Structure ◽  
Ft Ir ◽  
The Degree Of Crystallinity ◽  
By Products

Pure form,single phase and high crystalline zeolite 4A samples were synthesized during hydrothermal treatment of by-products in polysilicon production process. The effects of the different crystallization time on the degree of crystallinity, skeleton structure, morphology, size of the particle and its distribution of zeolite 4A samples were investigated using XRD,FT-IR,SEM and Zetasizer. The results indicated that the zeolite 4A sample featured high crystallinity degree, excellent dispersivity, high purity and single structure.

Metal ion interactions with sugars. The crystal structure and FT-IR study of the NdCl3–ribose complex

2003 ◽  
Vol 338 (24) ◽  
pp. 2913-2919 ◽  
Author(s):  
Yan Lu ◽  
Guocai Deng ◽  
Fangming Miao ◽  
Zhengming Li
Keyword(s):  
Crystal Structure ◽  
Metal Ion ◽  
Ion Interactions ◽  
Ft Ir ◽  
Ir Study ◽  
Metal Ion Interactions

scholarly journals Mineralogical and Fluid Inclusions Study of Epithermal Type Veins Intruding the Volcanic Rocks of the Kornofolia Area, Evros, NE Greece.

2019 ◽  
Vol 55 (1) ◽  
pp. 202
Author(s):  
Foteini Aravani ◽  
Lambrini Papadopoulou ◽  
Vasileios Melfos ◽  
Triantafillos Soldatos ◽  
Triantafillia Zorba ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Fluid Inclusion ◽  
Hydrothermal Alteration ◽  
Fluid Inclusions ◽  
Volcanic Rocks ◽  
The Other ◽  
Calc Alkaline ◽  
Ft Ir ◽  
Host Rocks

The volcanic rocks of Kornofolia area, Evros, host a number of epithermal-type veins. The host rocks are Oligocene calc-alkaline andesites to rhyo-dacites. The andesites form hydrothermal breccias and show hydrothermal alteration. The veins comprise mainly silica polymorphs such as quartz, chalcedony and three types of opal (milky white, transparent and green). Amethyst also forms in veins at the same area. Apart from the silica polymorphs, the veins are accompanied by calcite and zeolites. The main aim of this study is the characterization of the silica polymorphs. Using FT-IR analyses, variations in the crystal structure of the three opals were recognized. The green opal is found to be more amorphous than the other two types. Fluid-inclusion measurements were performed in calcite and were compared with amethyst from previous studies. The Th is between 121-175 °C and the Te between -22.9 and -22.4 °C. The salinities range from 0.9 to 4.5 wt % NaCl equiv.

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