Chemical Structure and Rheological Properties of Tara Polysaccharide Gum

2013 ◽  
Vol 821-822 ◽  
pp. 986-989
Author(s):  
Jin Ba ◽  
Li Qiang Jin ◽  
Wen Run Yao
Keyword(s):  
Shear Rate ◽  
Rheological Properties ◽  
Chemical Structure ◽  
Mass Ratio ◽  
Gas Chromatograph ◽  
Plant Polysaccharides ◽  
Mechanical Process ◽  
Composition And Structure ◽  
Ft Ir ◽  
Tree Seeds

Tara gum is a natural hydrocolloid obtained by a mechanical process from the endosperm of Tara tree seeds. In this study, chemical composition and structure of tara polysaccharide gum were characterized by fourier transform infrared spectroscopy (FT-IR) and gas chromatograph-mass spectrometer (GC-MS). Its rheological properties were also discussed. The results showed that tara gum had typical characteristics of plant polysaccharides, which was mainly consisted of galactose and mannose (mass ratio of galactose/mannose was 4.2:1), as well as a small amount of arabinose, glucose and xylose. The viscosity of tara gum solution was increased with the increase of its concentration. The tara gum solution demonstrated a higher viscocity at the shear rate lower than 80 Hz, but a higher elasticity at the shear rate higher than 80 Hz.

scholarly journals Viscosity sinergism of hydrozypropmethyl and carboxy methyl cellulose

2008 ◽  
Vol 62 (1) ◽  
pp. 31-36 ◽  
Author(s):  
Jaroslav Katona ◽  
Verica Sovilj ◽  
Lidija Petrovic
Keyword(s):  
Shear Rate ◽  
Rheological Properties ◽  
Binary Mixtures ◽  
Methyl Cellulose ◽  
Mass Ratio ◽  
Positive Deviation ◽  
Flow Properties ◽  
Concentration Changes ◽  
Overlap Concentration ◽  
Carboxy Methyl

Rheology modifiers are common constituents of food, cosmetic and pharmaceutic products. Often, by using two or more of them, better control of the product rheological properties can be achieved. In this work, rheological properties of hydroxypropymethyl cellulose (HPMC) and sodium carboxymethyl cellulose (NaCMC) solutions of different concentrations were investigated and compared to the flow properties of 1% HPMC/NaCMC binary mixtures at various HPMC/NaCMC mass ratios. Solutions of HPMC and NaCMC were found to be pseudoplastic, where pseudoplasticity increases with increase in the macromolecules concentration. Changes of the degree of pseudoplasticity, n as well as the coefficient of consistency, K with the concentration are more pronounced in HPMC solutions when compared to the NaCMC ones. This is mostly due to the ability of HPMC molecules to associate with each other at concentrations above critical overlap concentration, c , and greater flexibility of macromolecular chains. Binary mixtures of HPMC/NaCMC were also found to be pseudoplastic. Experimentally obtained viscosities of the mixture were proved to be larger than theoretically expected ones, indicating viscosity synergism as a consequence of HPMC-NaCMC interaction. Maximum in synergy was observed when HPMC/NaCMC mass ratio was 0.4/0.6, no matter of the shear rate applied. On the other hand, it was found that relative positive deviation, RPD decreases when shear rate is increased.

Characterization of Tri-(1, 4-Butanediol Single-Butyrate) Citrate as a New Plasticizer for Poly(Lactic Acid)

2013 ◽  
Vol 706-708 ◽  
pp. 32-35
Author(s):  
Tong Wan ◽  
Tao Du ◽  
Si Zhang
Keyword(s):  
Lactic Acid ◽  
Shear Rate ◽  
Parallel Plate ◽  
Chemical Structure ◽  
Poly Lactic Acid ◽  
Ft Ir

Tri-(1, 4-butanediol single-butyrate) citrate (TBBC) was synthesized as a new plasticizer for PLA. The chemical structure of TBBC was characterized by FT-IR. PLA was plasticized with various amount of TBBC. The effects of both temperature and shear rate on the rheologies of PLA/TBBC blends were evaluated by a parallel plate rheometer.

scholarly journals Experimental investigation on influence of microcapsules with PCM on propylene glycol rheological properties

2018 ◽  
Vol 70 ◽  
pp. 02005
Author(s):  
Krzysztof Dutkowski ◽  
Jacek Jan Fiuk
Keyword(s):  
Shear Rate ◽  
Rheological Properties ◽  
Propylene Glycol ◽  
Apparent Viscosity ◽  
Mean Absolute Error ◽  
Absolute Error ◽  
Mass Ratio ◽  
Test Range ◽  
State Measurement ◽  
Steady State Measurement

This paper details an experimental study that was performed to investigate rheological properties of microencapsulated phase change slurry - mPCM (Micronal® DS 5039 X and ERGOLID EKO®- an aqueous solution of propylene glycol). Seven samples of mPCM slurry were prepared with different mass ratio of the Micronal® to the ERGOLID EKO®: 30:70, 40:60, 50:50, 60:40, 70:30, 80:20 and 90:10. The apparent viscosity-shear rate curves were obtained for spindle speed from 0.01 to 100 rpm (shear rate 0.0132 to 132.00 s-1 respectively). The steady state measurement of viscosity was carried out when the slurry reached constant temperatures, namely: 10.0; 15.0, 17.5, 20.0, 22.5, 25.0, 27.5, 30.0, 40.0 and 50.0°C. The apparent viscosity of slurries increases with the mPCM concentration in dispersion rises. Only the sample of 30% Micronal® may be considered as a Newtonian fluid within the test range. Increasing the shear rate ultimately causes apparent viscosity to decrease down to the Newtonian plateau, where it seems to be constant. The variation of the viscosity as a function of temperature and microcapsules concentration was accurately represented by a modified Vogel-Tamman-Fulcher equation at a mean absolute error (MAE) of 10.76%.

Initiator Concentration Effect on Rheological Properties of a pH-Sensitive Semi-IPN Hydrogel Based on Konjac Glucomannan and Methacrylic Acid

2012 ◽  
Vol 627 ◽  
pp. 730-733 ◽  
Author(s):  
Chi Zhang ◽  
Hui Min Han ◽  
Peng Qu ◽  
Jing Xu ◽  
Ye Zhou ◽  
...  
Keyword(s):  
Free Radical ◽  
Rheological Properties ◽  
Chemical Structure ◽  
Polymer Network ◽  
Konjac Glucomannan ◽  
Ph Sensitive ◽  
Interpenetrating Polymer Network ◽  
Initiator Concentration ◽  
Buffer Solution ◽  
Ft Ir

A pH-sensitive semi-interpenetrating polymer network (semi-IPN) hydrogel based on Konjac glucomannan(KGM) and methylacrylic acid(MAA) was prepared by free radical polymerization at different concentrations of initiator potassium persulfate (KPS) in presence of crosslinker N,N-methylene-bis-acrylamide (MBA). The chemical structure and rheological properties of hydrogels were characterized by FT-IR and rheometry, respectively. In addition, the swelling behavior of the hydrogels were studied in buffer solution at different pHs.

Study on Themal and Rheological Properties of POM

2012 ◽  
Vol 487 ◽  
pp. 192-197
Author(s):  
Zhi Hong Guo ◽  
Zhen Xi Wen ◽  
Qing Yan Xu ◽  
Yuan Tian ◽  
Gao Qiu ◽  
...  
Keyword(s):  
Activation Energy ◽  
Shear Rate ◽  
Rheological Properties ◽  
Chemical Structure ◽  
Decomposition Temperature ◽  
Excellent Performance ◽  
Melt Temperature ◽  
Flow Activation Energy ◽  
Rate Range ◽  
Flow Activation

Polyoxymethylene is a linear polymer with excellent performance due to its chemical structure and high crystallinity. The thermal and rheological properties of POM are investigated in this paper. Experimental results indicate that the melting point and decomposition temperature of POM are about 162 °C and 266 °C respectively. POM melt is a non-Newtonian fluid, the apparent viscosity gradually decreased with the increase of shear rate, showing a typical shear-thinning behavior. Non-Newtonian index increased from 0.53 to 0.61 as the melt temperature increased from 190 °C to 230 °C. The flow activation energy of POM melt is between 11.36 and 24.90 kJ/mol within the shear rate range of 90~2500s -1.

Synthesis and Evaluation of Starch Graft Copolymer Applied as Dispersant in Coal-Water Slurry

2012 ◽  
Vol 549 ◽  
pp. 198-202
Author(s):  
Jun Guo Li ◽  
Fang Zhao ◽  
Guang Hua Zhang ◽  
Jun Feng Zhu ◽  
Long Liu
Keyword(s):  
Shear Rate ◽  
Chemical Structure ◽  
Styrene Sulfonate ◽  
Thermogravimetric Analyzer ◽  
Water Slurry ◽  
Oxidation Reduction ◽  
Coal Water Slurry ◽  
Initiator System ◽  
Ft Ir ◽  
Minimum Viscosity

In this paper, a starch-based dispersant for Chinese Shenhua coal-water slurry (CWS) was synthesized by radical polymerization using styrene sulfonate and acrylic acid as graft monomers in oxidation-reduction initiator system. Chemical structure and thermal performance of the copolymer were investigated by Fourier Transform Infrared Spectrum (FT-IR) and Thermogravimetric Analyzer (TGA). The rheological characteristics of the slurry were studied by varying dispersant dosage and shear rate，and the results show, At coal concentration of 66 wt%, dispersant dosage of 0.4 wt% and shear rate of 100 s-1, the CWS gives the minimum viscosity of 848 mPa•s. Bleeding ratio tests indicate the dispersant can stabilize the slurry. Based on the above, the starch-based dispersant has due structure and a bright prospect for the application for CWS.

Preparation and Characterization of Soybean Oil-based Flame Retardant Rigid Polyurethane Foams Containing Phosphaphenanthrene Groups

2020 ◽  
Vol 17 (10) ◽  
pp. 760-771
Author(s):  
Qirui Gong ◽  
Niangui Wang ◽  
Kaibo Zhang ◽  
Shizhao Huang ◽  
Yuhan Wang
Keyword(s):  
Soybean Oil ◽  
Flame Retardant ◽  
Chemical Structure ◽  
Cell Structure ◽  
Polyurethane Foams ◽  
Limiting Oxygen Index ◽  
Rigid Polyurethane Foams ◽  
Degradation Activation Energy ◽  
Ft Ir

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.

scholarly journals 5-((8-Hydroxyquinolin-5-yl)diazenyl)-3-methyl-1H-pyrazole-4-carboxylic Acid

Molbank ◽  
10.3390/m1238 ◽  
2021 ◽  
Vol 2021 (2) ◽  
pp. M1238
Author(s):  
Ion Burcă ◽  
Valentin Badea ◽  
Calin Deleanu ◽  
Vasile-Nicolae Bercean
Keyword(s):  
Chemical Structure ◽  
Functional Group ◽  
Coupling Reaction ◽  
2D Nmr ◽  
Azo Coupling ◽  
2D Nmr Spectroscopy ◽  
Azo Compound ◽  
Ft Ir ◽  
New Compounds ◽  
Carboxylic Functional Group

A new azo compound was prepared via the azo coupling reaction between 4-(ethoxycarbonyl)-3-methyl-1H-pyrazole-5-diazonium chloride and 8-hydroxyquinoline (oxine). The ester functional group of the obtained compound was hydrolyzed and thus a new chemical structure with a carboxylic functional group resulted. The structures of the new compounds were fully characterized by: UV–Vis, FT-IR, 1D and 2D NMR spectroscopy, and HRMS spectrometry.

Preparation, Structure and Thermolysis Characteristics of Ammonia Borane

2016 ◽  
Vol 680 ◽  
pp. 529-533
Author(s):  
Jian Li Ma ◽  
Hai Yan Cao ◽  
Xiao Xia Zhang ◽  
Dong Chen
Keyword(s):  
Boric Acid ◽  
Storage System ◽  
Ammonia Borane ◽  
Mass Ratio ◽  
Hydrogen Storage System ◽  
Ammonia Complex ◽  
Ft Ir ◽  
Ammonia Source ◽  
Boron Source ◽  
Amino Complex

Ammonia borane (NH3BH3, AB) is an excellent source of hydrogen(19.6 wt %) for fuel cell applications. In this paper, pure ammonia borane is successfully prepared by using amino complex for ammonia complex Ag(NH3)2Cl as new ammonia source, and sodium borohydride (NaBH4) as boron source. The composition and constitution of the products are measured by XRD and FT-IR. The thermolysis of ammonia borane is significant for its practical application. Boric acid plays a role in improving ammonia borane hydrogen performance. The effects of different mass ratio of boric acid and ammonia borane on dehydrogenation are tested by XRD, TG/DTA and TPD-MS. The results show that boric acid can decrease the first level dehydrogenation temperature of ammonia borane decrease to about 85°C (working temperature of PEMFC). What’s more, the onset temperature of AB’s thermolysis can decrease to about 60°C when the mass ratio of ammonia borane and boric acid is equal to 3:1. This makes ammonia borane be more suitable for the application in on-board hydrogen storage system.

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.

Sign in / Sign up

Export Citation Format

Share Document