scholarly journals Biodegradable Polyester Materials Containing Gallates

Polymers ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 677 ◽  
Author(s):  
Malgorzata Latos-Brozio ◽  
Anna Masek
Keyword(s):  
Thermal Stability ◽  
Antioxidant Properties ◽  
Polymer Materials ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Good Thermal Stability ◽  
Biodegradable Polyesters ◽  
High Oxidation

Gallates are widely used as antioxidants in the food and cosmetics industries. The purpose of the study was to obtain pro-ecological materials based on biodegradable polyesters, such as polylactide (PLA) and polyhydroxyalkanoate (PHA), and gallates. Gallates (ethyl, propyl, octyl, and lauryl) have not been used so far in biodegradable polymers as stabilizers and indicators of aging. This manuscript examines the properties of gallates such as antioxidant capacity and thermal stability. This paper also presents the following analyses of polymer materials: specific migration of gallates from polymers, SEM microscopy, differential scanning calorimetry (DSC), wide-angle X-ray diffraction, mechanical properties, surface free energy, and determination of change of color after controlled UV exposure, thermooxidation, and weathering. All gallates showed strong antioxidant properties and good thermal stability. Due to these properties, in particular their high oxidation temperature, gallates can be successfully used as polyester stabilizers. Biodegradable polyesters containing gallates can be an environmentally friendly alternative to petrochemical packaging materials.

scholarly journals Thermal behaviour study of solid state compounds of manganese (II), zinc (II) and lead (II) with cinnamic acid

1998 ◽  
Vol 23 (0) ◽  
pp. 09-16
Author(s):  
Marco Aurélio da Silva CARVALHO FILHO ◽  
Massao IONASHIRO
Keyword(s):  
Thermal Stability ◽  
Aqueous Solution ◽  
Differential Scanning Calorimetry ◽  
Cinnamic Acid ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Manganese Zinc ◽  
Behaviour Study ◽  
Derivative Thermogravimetry

Compounds of cinnamic acid with manganese, zinc and lead have been prepared in aqueous solution. Thermogravimetry, derivative thermogravimetry (TG, DTG), differential scanning calorimetry (DSC), X-ray diffraction and complexometry have been used in the characterization as well as in the study of the thermal stability and interpretation concerning the thermal decomposition.

scholarly journals Ellagic Acid May Improve Mechanical and Barrier Properties in Films of Starch-A Review Paper

2016 ◽  
Vol 5 (3) ◽  
pp. 61
Author(s):  
J. M. Tirado-Gallegos ◽  
D. R. Sepúlveda-Ahumada ◽  
P. B. Zamudio-Flores ◽  
M. L. Rodríguez-Marin ◽  
Francisco Hernández-Centeno ◽  
...  
Keyword(s):  
Ellagic Acid ◽  
Structural Changes ◽  
Antioxidant Properties ◽  
Barrier Properties ◽  
Packaging Materials ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Film Forming ◽  
Starch Films

<p>Packaging increases the shelf life of food and facilitates its handling, transportation and marketing. The main packaging materials are plastics derived from petroleum, but their accumulation has given rise to environmental problems. An alternative is the use of biodegradable materials. In this regard, starch is an excellent choice because it is an abundant and renewable source with film-forming properties. However, the films obtained from starch have some limitations with respect to their mechanical and barrier properties. Several strategies have been developed in order to improve these limitations, ranging from the addition of lipids to the modification of the polymer structure. The aim of this review was propose the use of ellagic acid as a cross-linking agent that may improves the mechanical and barrier properties in films based on exists reports that phenolic compounds interact with starch-based materials decreasing their rate of retrogradation. Furthermore, ellagic acid is a powerful natural antioxidant, which would allow the production of active packaging with antioxidant properties, in addition to the improvement of the mechanical and barrier properties of starch films. In this concern more studies such as Fourier transform infrared spectroscopy, X-ray diffraction, differential scanning calorimetry and thermogravimetric analysis are necessary to verify the structural changes and interactions between starch and ellagic acid. We expect extensive use of it in the future of packaging materials.</p>

Study of the structure and thermal characteristics of nanocomposites based on polyvinyl alcohol and intercalated montmorillonite

2019 ◽  
pp. 089270571987919
Author(s):  
Volodymyr Krasinskyi ◽  
Ivan Gajdos ◽  
Oleh Suberlyak ◽  
Viktoria Antoniuk ◽  
Tomasz Jachowicz
Keyword(s):  
Thermal Stability ◽  
Differential Scanning Calorimetry ◽  
Acrylic Acid ◽  
Polyvinyl Alcohol ◽  
Thermal Characteristics ◽  
Degree Of Crystallinity ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
The Degree Of Crystallinity

The structure and thermal characteristics of nanocomposites based on polyvinyl alcohol (PVA) and montmorillonite (MMT) intercalated with polyvinylpyrrolidone were investigated by X-ray diffraction analysis and differential scanning calorimetry. The modification of PVA with intercalated MMT reduces the degree of crystallinity of the resulting nanocomposites but significantly increases their thermal stability. Under ultrasound, the intercalated MMT was completely distributed in a PVA solution and formed a monocrystalline structure. Films based on PVA with modified MMT were cross-linked at 110°C in the presence of 5 wt% acrylic acid and 0.5 wt% Ferrous(II) sulfate as an initiator. The formed films have a homogeneous cross-linked structure.

Polypseudorotaxane Hydrogels Based on F127 Block-Selected Inclusion Complexation with α-Cyclodextrin

2012 ◽  
Vol 482-484 ◽  
pp. 1898-1903
Author(s):  
Ying Xue Zhou ◽  
Xiao Dong Fan ◽  
Dan Xue
Keyword(s):  
Thermal Stability ◽  
Inclusion Complex ◽  
Inclusion Complexation ◽  
Wide Angle ◽  
Acryloyl Chloride ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Thermal Stability Of ◽  
Channel Type

Supramolecular hydrogels were formed through F127, acryloyl chloride modified F127 inclusion complex with α-cyclodextrin, respectively. The structure of modified copolymers and inclusion complex was characterized by Fourier transform infrared spectroscopy (FTIR) and hydrogen nuclear magnetic resonance (1H-NMR). Hydrogels formed from supramolecular inclusion are imparted channel-type structure investigated by wide angle x-ray diffraction (WAXRD). Differential scanning calorimetry (DSC) and TG experiments showed that thermal stability of hydrogels depend on the nature of axis polymer. The relative model was proposed to elucidate the inclusion complexes and hydrogels formation.

Study of an Energetic-oxidant Co-crystal: Preparation, Characterisation, and Crystallisation Mechanism

2017 ◽  
Vol 67 (5) ◽  
pp. 510 ◽  
Author(s):  
Han Gao ◽  
Wei Jiang ◽  
Jie Liu ◽  
Gazi Hao ◽  
Lei Xiao ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Differential Scanning Calorimetry ◽  
Diffraction Spectrum ◽  
Solvent Evaporation Method ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Scanning Electron

<p>An energetic co-crystal consisting of the most promising military explosive 2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane (CL-20) and the most well-known oxidant applied in propellants ammonium perchlorate has been prepared with a simple solvent evaporation method. Scanning electron microscopy revealed that the morphology of co-crystal differs greatly from each component. The X-ray diffraction spectrum, FTIR, Raman spectra, and differential scanning calorimetry characterisation further prove the formation of the co-crystal. The result of determination of hygroscopic rate indicated the hygroscopicity was effectively reduced. At last, the crystallisation mechanism has been discussed.</p>

Ti Microalloying Effect on Corrosion Resistance and Thermal Stability of Cu45Zr48Al7 Bulk Metallic Glass

2012 ◽  
Vol 490-495 ◽  
pp. 3868-3873 ◽  
Author(s):  
Xiao Hong Yang ◽  
Xi Peng Nie ◽  
Jian Zhong Jiang
Keyword(s):  
Thermal Stability ◽  
Corrosion Resistance ◽  
Metallic Glasses ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Glass Forming ◽  
Ti Addition ◽  
Mould Casting ◽  
Thermal Stability Of

Bulk metallic glasses (BMGs) of Cu45Zr48-xAl7Tix with x= 0, 1.5, and 3 at.% were prepared by copper mould casting. The corrosion resistance of the BMGs with different Ti contents was examined by potentiodynamic polarization tests and weight loss measurements in 1 N NaOH, 1 N H2SO4, 1 N H2SO4 + 0.01 N NaCl and 0.5 N NaCl solutions, respectively. The newly-developed BMGs’ corrosion resistance in Cl-- or both H+ and Cl--ions containing solutions can be greatly enhanced. The influence of Ti addition on glass forming ability (GFA) and thermal stability was investigated by x-ray diffraction and differential scanning calorimetry in detail. The alloy containing 1.5 at.% Ti exhibits the largest GFA, the critical size comes up to 10 mm in diameter.

Pd/SiO2 Organic-Inorganic Hybrid Materials by Sol-Gel Method: Preparation and Thermal Stability under H2 Atmosphere

2015 ◽  
Vol 1118 ◽  
pp. 20-27
Author(s):  
Jing Yang ◽  
Bao Song Li ◽  
Xiang Huo ◽  
Hao Xu ◽  
Hai Yun Hou
Keyword(s):  
Thermal Stability ◽  
Calcination Temperature ◽  
Hybrid Materials ◽  
Photoelectron Spectroscopy ◽  
Sol Gel ◽  
X Ray Diffraction ◽  
Inorganic Hybrid ◽  
X Ray ◽  
Good Thermal Stability ◽  
Pd Doping

Pd/SiO2 organic-inorganic hybrid materials were prepared by adding PdCl2 into methyl-modified silica sol. The Pd/SiO2 hybrid materials were characterized by X-ray diffraction (XRD), fourier transform infrared (FTIR) and X-ray photoelectron spectroscopy (XPS). The effects of calcination temperature and Pd-doping on the phase transition of Pd element and the thermal stability of CH3 group in the Pd/SiO2 organic-inorganic hybrid materials were investigated. The results showed that the reduced metallic Pd0 exhibits good thermal stability under H2 atmosphere in the calcination process. Pd element in noncalcined Pd/SiO2 materials exists in PdCl2 form, calcination at 200 °C in a H2 atmosphere produces some metallic Pd0 and calcinations at 350 °C results in the complete transformation of Pd2+ to metallic Pd0. With the increase of calcination temperature, the Pd0 particle sizes increase and the hydrophobic Si−CH3 bands decrease in intensity. As the calcination temperature is greater than or equal to 350 °C, the loading of metallic Pd0 nearly has no influence on the chemical structure but, with the increase of Pd content, the formed Pd0 particle size increases. To keep the hydrophobicity of Pd/SiO2 membrane materials, the optimal calcination temperature is about 350 °C under H2 atmosphere.

scholarly journals Stable Organic-Inorganic Hybrid Bismuth-Halide Monocrystalline Compounds With Adjustable Optoelectronic Properties

2021 ◽  
Author(s):  
Xinru Hu ◽  
Jilin Wang ◽  
Jian He ◽  
Guoyuan Zheng ◽  
Disheng Yao ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Room Temperature ◽  
Diffuse Reflectance ◽  
Decomposition Temperature ◽  
X Ray Diffraction ◽  
Monoclinic System ◽  
X Ray ◽  
Good Thermal Stability ◽  
Chemical Groups ◽  
Thermal Stability Of

Abstract Two kinds of novel organic-inorganic bismuth-halide hybrid monocrystalline compounds (C6H5CH2NH3)2BiCl5 and (C6H5CH2NH3)BiI4 were synthesized and characterized. The crystal structure, intermolecular interaction, morphology, chemical groups and bonds, optical and thermal stability of the samples were systematically investigated through single crystal X-ray diffraction, Hirshfeld surface analysis, SEM, FTIR, TG and UV-vis diffuse reflectance spectra. The results indicated that (C6H5CH2NH3)2BiCl5 and (C6H5CH2NH3)BiI4 crystals displayed a monoclinic system with the space group P21/c and P21/n at room temperature, respectively. These materials showed strong absorption in the ultraviolet and visible light regions, resulting in very low Eg, which could be continuously adjustable from 1.67 eV to 3.21 eV by changing the halogen ratio. In addition, these hybrid materials also exhibited good thermal stability. The decomposition temperature of (C6H5CH2NH3)2BiCl5 and (C6H5CH2NH3)BiI4 were 260℃ and 300℃ respectively. Therefore, these organic-inorganic bismuth-halide hybrid compounds have excellent development potential in the field of solar cell research.

scholarly journals Preparation and thermal decomposition of solid state cinnamates of alkali earth metals, except beryllium and radium

1998 ◽  
Vol 23 (0) ◽  
pp. 91-98 ◽  
Author(s):  
Ana Glauce ZAINA CHIARETTO ◽  
Marco Aurélio da Silva CARVALHO FILHO ◽  
Nedja Suely FERNANDES ◽  
Massao IONASHIRO
Keyword(s):  
Thermal Stability ◽  
Differential Scanning Calorimetry ◽  
Thermal Decomposition ◽  
Solid State ◽  
General Formula ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Preparation And Thermal Decomposition ◽  
Derivative Thermogravimetry

Solid state compounds of general formula ML2.nH2O [where M is Mg, Ca, Sr or Ba; L is cinnamate (C6H5 -CH=CH-COO-) and n = 2, 4, 0.8, 3 respectively], have been synthetized. Thermogravimetry (TG), derivative thermogravimetry (DTG), differential scanning calorimetry (DSC) and X-ray diffraction powder patterns have been used to characterize and to study the thermal stability and thermal decomposition of these compounds.

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