Study on Property of Acid-Modified Kudzu Starch

2012 ◽  
Vol 602-604 ◽  
pp. 1325-1329
Author(s):  
Yan Ping Li ◽  
Si Qing Dong ◽  
Hong Bo Tang ◽  
Ling Guo Wang
Keyword(s):  
Acid Resistance ◽  
Salt Resistance ◽  
Decomposition Temperature ◽  
Enthalpy Change ◽  
Alkali Resistance ◽  
Scanning Calorimetry ◽  
Freeze Thaw ◽  
Swelling Power ◽  
Acid And Alkali Resistance ◽  
Thermal Stability Of

The properties of the acid modified kudzu starch such as the thermal stability of viscosity, swelling power, transparency, freeze-thaw stability, blue value, acid and alkali resistance, salt resistance and retrogradation was studied in order to enlarge its application in this paper. The thermal properties were analyzed by means of differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). The results indicated that the swelling power, transparency, freeze-thaw, acid resistance, alkali resistance, blue value increased with increasing the degree of acidolysis of kudzu starch. Compared with kudzu starch, acid hydrolysis increased the decomposition temperature, but reduced the enthalpy change from the thermal analysis.

Optimization of Hydroxyropylation Conditions and Property of Acid-Modified Hydroxypropyl Pueraria Lobata Starch

2012 ◽  
Vol 518-523 ◽  
pp. 3921-3930 ◽  
Author(s):  
Hong Bo Tang ◽  
Min Sun ◽  
Yan Ping Li ◽  
Si Qing Dong
Keyword(s):  
Acid Hydrolysis ◽  
Anhydrous Sodium Sulfate ◽  
Decomposition Temperature ◽  
Alkali Resistance ◽  
Pueraria Lobata ◽  
Gravimetric Analysis ◽  
Scanning Calorimetry ◽  
Substitution Degree ◽  
Acid And Alkali Resistance ◽  
Application Fields

In order to improve the property of pueraria lobata starch, and enlarge application fields of pueraria lobata starch, this study involved in the optimization of determining parameters in hydroxyropylation conditions and the property of acid-modified hydroxypropyl pueraria lobata starch with low substitution degree (DS).Characterizations were carried out by analyzing the spectrum of the thermograms of differential scanning calorimetry (DSC) and thermal gravimetric analysis (TGA). The fludity was used for characterizing the degree of acid hydrolysis. The substitution degree was measured by the spectrophotometric method. The optimized hydroxyropylation conditions were as follows: reaction temperature 40°C, reaction time 18h, amount of sodium hydroxide 1.2%, amount of anhydrous sodium sulfate 12%, respectively. The properties such as the transparency, freeze-thaw stability, blue value, swelling power, retrogradation, acid and alkali resistance of acid-modified hydroxypropyl pueraria lobata starch were compared with those of pueraria lobata starch and acid-modified pueraria lobata starch. It was shown that acid hydrolysis and hydroxyropylation increased the decomposition temperature, but reduced the enthalpy value from the thermal analysis.

Preparation, characterization, and properties of polystyrene/Na-montmorillonite composites

2018 ◽  
Vol 32 (8) ◽  
pp. 1078-1091 ◽  
Author(s):  
Sibel Erol Dağ ◽  
Pınar Acar Bozkurt ◽  
Fatma Eroğlu ◽  
Meltem Çelik
Keyword(s):  
Electron Microscopy ◽  
Interlayer Spacing ◽  
Decomposition Temperature ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Sem Images ◽  
Specific Pore Volume ◽  
Transmission Electron ◽  
Thermal Stability Of

A series of polystyrene (PS)/unmodified Na-montmorillonite (Na-MMT) composites were prepared via in situ radical polymerization. The prepared composites were characterized using various techniques. The presence of various functional groups in the unmodified Na-MMT and PS/unmodified Na-MMT composite was confirmed by Fourier transform infrared spectroscopy. Morphology and particle size of prepared composites was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). According to the XRD and TEM results, the interlayer spacing of MMT layers was expanded. SEM images showed a spongy and porous-shaped morphology of composites. TEM revealed the Na-MMT intercalated in PS matrix. The thermal stability of PS/unmodified Na-MMT composites was significantly improved as compared to PS, which is confirmed using thermogravimetric analysis (TGA). The TGA curves indicated that the decomposition temperature of composites is higher at 24–51°C depending on the composition of the mixture than that of pure PS. The differential scanning calorimetry (DSC) results showed that the glass transition temperature of composites was higher as compared to PS. The moisture retention, water uptake, Brunauer–Emmett–Teller specific surface area, and specific pore volume of composites were also investigated. Water resistance of the composites can be greatly improved.

scholarly journals Preparation and Properties of Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) and Polypropylene Grafting Maleic Anhydride Two-Component Materials

2018 ◽  
Vol 26 (3(129)) ◽  
pp. 17-22 ◽  
Author(s):  
Xichao Sun ◽  
Yeqian Ge
Keyword(s):  
Maleic Anhydride ◽  
High Sensitivity ◽  
Crystal Form ◽  
Decomposition Temperature ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Melt Mixing ◽  
Two Component ◽  
Thermal Analyser ◽  
Thermal Stability Of

In order to provide a theoretical basis for the preparation and spinnability of two-component materials, poly(3-hydroxybutyrate-co-3-hydroxyvalerate)(PHBV) and polypropylene grafting maleic anhydride (PP-g-MAH) blends were prepared by melt mixing with different ratios (100/0, 75/25, 50/50, 25/75, 0/100). Properties of the blends system were investigated by means of a mixed rheometer, scanning electron microscope, simultaneous thermal analyser, differential scanning calorimetry and X-ray diffraction. The results demonstrate that PHBV/PP-g-MAH blends exhibit different morphology of the sea-island with a change in the mix ratio. The initial thermal decomposition temperature of PHBV in the blending system is over 250 °C, which means the thermal stability of PHBV is markedly improved. The crystallisation of PHBV varied according to the blending process parameter. When the cooling velocity increases, the crystallisation peak becomes wide, the temperature of crystallisation decreases, and the crystallisation temperature of PHBV increases significantly. PHBV has a high sensitivity to variation in the shear rate, and PHBV/PP-g-MAH blends have the mixing characteristic of shear thinned liquid. There is no diffraction peak at 2θ = 22.8°, and this result certifies that PP-g-MAH changes the crystal form of PHBV. and that PP-g-MAH addition is beneficial to the spinnability of PHBV. Results show that the interplay between PHBV and PP-g-MAH is of great significance and universal for both plastics and fibres.

Preparation and Characterization of Polypropylene/Clay Nanocomposites

2011 ◽  
Vol 55-57 ◽  
pp. 1584-1587 ◽  
Author(s):  
Li Mei Wang
Keyword(s):  
Xrd Analysis ◽  
Decomposition Temperature ◽  
Clay Nanocomposites ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Xrd Pattern ◽  
Solution Blending ◽  
Clay Layers ◽  
Thermal Stability Of

Polypropylene(PP)/clay nanocomposites were prepared by solution blending. The microstructure of PP/clay nanocomposites was studied by wide-angle X-ray diffraction (XRD) analysis. Differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) were used to investigate thermal properties of PP/clay nanocomposites. XRD pattern prove that clay layers were exfoliated into nanometer size in PP matrix and that α-Phase crystallite was the main crystallite of PP in PP/clay nanocomposites. TGA examinations confirmed that the maximum decomposition temperature of PP/clay nanocomposites was higher than that of neat PP and that the thermal stability of PP/clay nanocomposites rose noticeably. Results of DSC scans showed the crystalliztion temperature of nanocomposites was slightly bigger than that of pure PP due to the efficient nucleating effects of clay layers.

scholarly journals An Investigation on the Comprehensive Property Assessment and Future Directions of Single Bamboo Fiber Reinforced Polypropylene Composites Fabricated by a Non-Woven Paving and Advanced Molding Process

Materials ◽  
2019 ◽  
Vol 12 (16) ◽  
pp. 2641 ◽  
Author(s):  
Tang ◽  
Wang ◽  
Wang ◽  
Cheng ◽  
Guo
Keyword(s):  
Thermal Stability ◽  
Impact Strength ◽  
Water Resistance ◽  
Decomposition Temperature ◽  
Modulus Of Rupture ◽  
Gravimetric Analysis ◽  
Molding Process ◽  
Scanning Calorimetry ◽  
Bamboo Fibers ◽  
Thermal Stability Of

The demand for eco-friendly renewable natural fibers has grown in recent years. In this study, a series of polypropylene-based composites reinforced with single bamboo fibers (SBFs), prepared by non-woven paving and a hot-pressing process, were investigated. The influence of the content of SBF on impact strength, flexural strength, and water resistance was analyzed. The properties of the composites were greatly affected by the SBF content. Impact strength increased as SBF content increased. The modulus of rupture and modulus of elasticity show an optimum value, with SBF contents of 40% and 50%, respectively. The surface morphology of the fractured surfaces of the composites was characterized by scanning electron microscopy. The composites showed poor interfacial compatibility. The water resistance indicates that the composites with higher SBF contents have higher values of water absorption and thickness swelling, due to the hydrophilicity of the bamboo fibers. The thermal properties of the composites were characterized by thermal gravimetric analysis and by differential scanning calorimetry. The thermal stability of the composites was gradually reduced, due to the poor thermal stability of SBFs. In the composites, the maximum decomposition temperature corresponding to SBF shows an increasing trend. However, the maximum decomposition temperature of polypropylene was not influenced by SBF content. The melting point of the polypropylene in the composites was lower relative to pure polypropylene, although it was not affected by increasing SBF content.

scholarly journals Thermal Stability Analysis of Lithium-Ion Battery Electrolytes Based on Lithium Bis(trifluoromethanesulfonyl)imide-Lithium Difluoro(oxalato)Borate Dual-Salt

Polymers ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 707
Author(s):  
Ya-Ping Yang ◽  
An-Chi Huang ◽  
Yan Tang ◽  
Ye-Cheng Liu ◽  
Zhi-Hao Wu ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Model Fitting ◽  
Lithium Ion ◽  
Decomposition Temperature ◽  
Scanning Calorimetry ◽  
Thermal Decomposition Process ◽  
Autocatalytic Model ◽  
Pyrolysis Kinetic ◽  
Thermal Stability Of ◽  
Better Than

Lithium-ion batteries with conventional LiPF6 carbonate electrolytes are prone to failure at high temperature. In this work, the thermal stability of a dual-salt electrolyte of lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) and lithium difluoro(oxalato)borate (LiODFB) in carbonate solvents was analyzed by accelerated rate calorimetry (ARC) and differential scanning calorimetry (DSC). LiTFSI-LiODFB dual-salt carbonate electrolyte decomposed when the temperature exceeded 138.5 °C in the DSC test and decomposed at 271.0 °C in the ARC test. The former is the onset decomposition temperature of the solvents in the electrolyte, and the latter is the LiTFSI-LiODFB dual salts. Flynn-Wall-Ozawa, Starink, and autocatalytic models were applied to determine pyrolysis kinetic parameters. The average apparent activation energy of the dual-salt electrolyte was 53.25 kJ/mol. According to the various model fitting, the thermal decomposition process of the dual-salt electrolyte followed the autocatalytic model. The results showed that the LiTFSI-LiODFB dual-salt electrolyte is significantly better than the LiPF6 electrolyte in terms of thermal stability.

Investigations on Properties Determining Durability of Novel PCC

2013 ◽  
Vol 688 ◽  
pp. 130-138 ◽  
Author(s):  
Winfried Malorny ◽  
Marleen Plath
Keyword(s):  
Ambient Temperature ◽  
Acid Resistance ◽  
Polymeric Materials ◽  
Salt Resistance ◽  
Concrete Repair ◽  
Freeze Thaw ◽  
Structural Repair ◽  
Soft State ◽  
Reference Samples

Polymer-modified mortars have been used in concrete repair for decades. Typical polymeric mate-rials used for this purpose are those which are in the soft state at ambient temperature. Our own studies focus on hard polymeric materials (hard and brittle at ambient temperature) which offer promising potential for structural repair. Our contribution reports on the results of studies on freeze thaw salt resistance and acid resistance relevant to durability. The results are compared to unmodi-fied reference samples and show the major potential of PCC modified with hard polymers; the ben-efits of PCC are evident.

Thermal properties and thermal stability of polypropylene composites filled with graphene nanoplatelets

2017 ◽  
Vol 31 (2) ◽  
pp. 246-264 ◽  
Author(s):  
JZ Liang ◽  
JZ Wang ◽  
Gary CP Tsui ◽  
CY Tang
Keyword(s):  
Thermal Stability ◽  
Thermal Properties ◽  
Weight Fraction ◽  
Decomposition Temperature ◽  
Graphene Nanoplatelets ◽  
Filler Concentration ◽  
Scanning Calorimetry ◽  
Lateral Dimension ◽  
Polypropylene Composites ◽  
Thermal Stability Of

The thermal properties and thermal stability of polypropylene (PP) composites separately filled with graphene nanoplatelets (GNPs) with three different sizes were measured using a differential scanning calorimetry and a thermal gravimetric analyser. The results showed that the values of the melting temperature of the composites were higher than that of the unfilled PP; the thermal stability increased with increasing the weight fraction and lateral dimension of GNPs in the case of low filler concentration, while the effect of the GNPs thickness on the thermal stability was insignificant; the onset decomposition temperature increased with increasing the GNPs lateral dimension, while the maximum thermal decomposition rate increased first and then decreased with increasing the GNPs weight fraction. The thermal stability improvement should be attributed to the sheet barrier function of the GNPs.

Study on the Structure and Performance of the Large Diameter PPS/PA6 Blending Monofilaments

2011 ◽  
Vol 233-235 ◽  
pp. 1694-1699
Author(s):  
Hai Yan Ma ◽  
Zhao Feng Liu ◽  
Jun Zhang ◽  
Hai Jun Ma
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Comparative Analysis ◽  
Large Diameter ◽  
Acid Resistance ◽  
Alkali Resistance ◽  
Acid And Alkali Resistance ◽  
And Performance

PPS and PA6were blended to improve the mechanical properties of the large diameter PPS monofilaments. The influence of the structure of the blends on the blending monofilaments, the comparative analysis with relevant polymer monofilaments and the acid and alkali resistance were studied in this article. The results demonstrated that: the mechanical properties of the PPS monofilaments were improved. The tensile strength and the collaboration strength of the monofilaments increased. The toughness of the PPS monofilaments increased. Simultaneously, the acid resistance and the alkali resistance of the PPS monofilaments were retained in the PPS/PA6blending monofilaments.

scholarly journals Properties of Bitumen Composition Modified by Petroleum Resins

2021 ◽  
pp. 147-155
Author(s):  
Vladimir G. Bondaletov ◽  
Liudmila I. Bondaletova ◽  
Van Thanh Nguyen ◽  
Anna V. Bondaletova
Keyword(s):  
Titanium Tetrachloride ◽  
Protective Coatings ◽  
Acid Resistance ◽  
Salt Resistance ◽  
Alkali Resistance ◽  
Modified Bitumen ◽  
Pyrolysis Products ◽  
Liquid Pyrolysis Products ◽  
Chloride Catalyst ◽  
Different Content

It was advised to use aliphatic, cycloaliphatic, aromatic petroleum resins and their derivatives obtained by oxidation of resins with a mixture of hydrogen peroxide and acetic acid as bitumen polymer-modifiers. Petroleum resins were obtained by ionic polymerization of unsaturated compounds of liquid pyrolysis products under the influence of titanium tetrachloride-diethylaluminium chloride catalyst. It was established that the maximum values of adhesion of modified bitumen coatings to metal substrates, corresponding to the minimum values of the wetting angle of the metal surface coated with solutions of bitumen compositions with different content of the polymer modifier were achieved using oxidized resins. All modified bitumen coatings have low water absorptivity and high acid resistance, alkali resistance and salt resistance, which allow using them as protective coatings

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