Correlations of the Antioxidant Properties of Softwood Kraft Lignin Fractions with the Thermal Stability of Its Blends with Polyethylene

2015 ◽  
Vol 3 (2) ◽  
pp. 349-356 ◽  
Author(s):  
Hasan Sadeghifar ◽  
Dimitris S. Argyropoulos
Keyword(s):  
Thermal Stability ◽  
Antioxidant Properties ◽  
Kraft Lignin ◽  
Softwood Kraft Lignin ◽  
Thermal Stability Of

Effects of different monosaccharides on thermal stability of phycobiliproteins from Oscillatoria sp. (BTA-170): Analysis of kinetics, thermodynamics, colour and antioxidant properties

2021 ◽  
Vol 44 ◽  
pp. 101354
Author(s):  
Ramesh Sharma ◽  
Pinku Chandra Nath ◽  
Kondi Vanitha ◽  
Onkar Nath Tiwari ◽  
Tarun Kanti Bandyopadhyay ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Antioxidant Properties ◽  
Thermal Stability Of

Methylation of softwood kraft lignin with dimethyl carbonate

2015 ◽  
Vol 17 (2) ◽  
pp. 1077-1087 ◽  
Author(s):  
Sanghamitra Sen ◽  
Shradha Patil ◽  
Dimitris S. Argyropoulos
Keyword(s):  
Thermal Stability ◽  
Dimethyl Carbonate ◽  
Kraft Lignin ◽  
Softwood Kraft Lignin

Methylation of lignin is essential for inducing thermal stability when a multitude of thermoplastic applications are envisaged.

scholarly journals Synthesis and characterization of kraft lignin-based epoxy resins

BioResources ◽  
2011 ◽  
Vol 6 (3) ◽  
pp. 2492-2503
Author(s):  
Nour-Eddine El Mansouri ◽  
Qiaolong Yuan ◽  
Farong Huang
Keyword(s):  
Thermal Stability ◽  
Epoxy Resins ◽  
1H Nmr Spectroscopy ◽  
Kraft Lignin ◽  
Synthesis And Characterization ◽  
Index Test ◽  
Optimal Conditions ◽  
Application Potential ◽  
Thermal Stability Of

Epoxidization is an interesting way to develop a new application of lignin and therefore to improve its application potential. In this work, kraft lignin-based epoxy resins were obtained by the epoxidization reaction, using the kraft lignin recovered directly from pulping liquor and modified by a methylolation reaction. The methylolated lignins were obtained by the reaction of original kraft lignin with formaldehyde and glyoxal, which is a less volatile and less toxic aldehyde. 1H-NMR spectroscopy showed that methylolated kraft lignin has more hydroxymethyl groups than glyoxalated kraft lignin. For the epoxidization reaction we studied the influence of the lignin:NaOH (w/w) ratio, temperature, and time of the reaction on the properties of the prepared epoxidized lignins. The structures of lignin-based epoxy resins were followed by epoxy index test and FTIR spectroscopy. Optimal conditions were obtained for lignin-based epoxy resin produced at lignin/NaOH = 1/3 at 70 ºC for 3h. Thermogravimetry analysis (TGA) revealed that the epoxidization enhances the thermal stability of lignins and may allow a wider temperature range for applications with lignin epoxy-PF blends.

scholarly journals Thermal Stability and Decomposition Mechanism of PLA Nanocomposites with Kraft Lignin and Tannin

Polymers ◽  
2021 ◽  
Vol 13 (16) ◽  
pp. 2818
Author(s):  
Nina Maria Ainali ◽  
Evangelia Tarani ◽  
Alexandra Zamboulis ◽  
Klementina Pušnik Črešnar ◽  
Lidija Fras Zemljič ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Thermal Degradation ◽  
Food Packaging ◽  
Degradation Kinetics ◽  
Kraft Lignin ◽  
Thermal Degradation Kinetics ◽  
Gas Chromatography Mass Spectrometry ◽  
Poly Lactic Acid ◽  
Pyrolysis Gas ◽  
Thermal Stability Of

Packaging applications cover approximately 40% of the total plastics production, whereas food packaging possesses a high proportion within this context. Due to several environmental concerns, petroleum-based polymers have been shifted to their biobased counterparts. Poly(lactic acid) (PLA) has been proved the most dynamic biobased candidate as a substitute of the conventional polymers. Despite its numerous merits, PLA exhibits some limitations, and thus reinforcing agents are commonly investigated as fillers to ameliorate several characteristics. In the present study, two series of PLA-based nanocomposites filled with biobased kraft-lignin (KL) and tannin (T) in different contents were prepared. A melt–extrusion method was pursued for nanocomposites preparation. The thermal stability of the prepared nanocomposites was examined by Thermogravimetric Analysis, while thermal degradation kinetics was applied to deepen this process. Pyrolysis–Gas Chromatography/Mass Spectrometry was employed to provide more details of the degradation process of PLA filled with the two polyphenolic fillers. It was found that the PLA/lignin nanocomposites show better thermostability than neat PLA, while tannin filler has a small catalytic effect that can reduce the thermal stability of PLA. The calculated Eα value of PLA-T nanocomposite was lower than that of PLA-KL resulting in a substantially higher decomposition rate constant, which accelerate the thermal degradation.

scholarly journals Curcumin Incorporated Poly(Butylene Adipate-co-Terephthalate) Film with Improved Water Vapor Barrier and Antioxidant Properties

Materials ◽  
2020 ◽  
Vol 13 (19) ◽  
pp. 4369
Author(s):  
Swarup Roy ◽  
Jong-Whan Rhim
Keyword(s):  
Thermal Stability ◽  
Antimicrobial Activity ◽  
Antioxidant Activity ◽  
Water Vapor ◽  
Antioxidant Properties ◽  
Water Vapor Permeability ◽  
Vapor Permeability ◽  
Water Vapor Barrier ◽  
Bright Yellow ◽  
Thermal Stability Of

Curcumin incorporated poly(butylene adipate-co-terephthalate) (PBAT) based film was fabricated. Curcumin has uniformly distributed in the PBAT matrix to form a bright yellow PBAT/curcumin film. The PBAT/curcumin film has slightly reduced tensile strength and flexibility than the neat PBAT film, while the thermal stability of the film has not changed significantly. The blending of curcumin significantly decreased the water vapor permeability of the PBAT film. Additionally, the PBAT/curcumin film showed potent antioxidant activity with some antimicrobial activity. The PBAT/curcumin films with improved water vapor barrier and additional functions can be used for active packaging applications.

Eugenol Supplementation as an Additive to Improve the Thermal Stability of Hedychium coronarium Koening Essential Oil

2020 ◽  
Vol 10 (3) ◽  
pp. 279-285
Author(s):  
Julyleth P.J. Macias ◽  
Ricardo I. Castro ◽  
Saray K.G. Esguerra ◽  
Jaime G. Marin ◽  
Luis Guzman ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Essential Oil ◽  
Biological Activities ◽  
Wide Spectrum ◽  
Antioxidant Properties ◽  
Antioxidant Additive ◽  
Strong Light ◽  
Hedychium Coronarium ◽  
Pharmaceutical Industries ◽  
Thermal Stability Of

Background: Eugenol is a phenolic compound with a wide spectrum of biological activities such as antibacterial and antioxidant. Objective: Eugenol is an ideal candidate as a natural antioxidant additive, especially for those substances that are affected by lipoperoxidation process, this is the case of essential oils that have an important role in the food, perfumery and pharmaceutical industries, which easily deteriorate under high temperature, strong light, and reactive oxygen species. Methods: In order to evidence the influence of the addition of eugenol in the thermal properties of Hedychium coronarium Koening essential oil, were determined the chemical composition, antioxidant properties and TG/DTG analysis after the supplementation with different ratios of eugenol/essential oil. Results: The results showed a high content of oxygenated monoteropenes (50.33%), followed by monoterpene hydrocarbons (23.35%) and sesquiterpene (19.2%), the TG/DTG analysis presented a significant increment in the degradation temperature of the essential oil, being the major value 12 ºC at a supplementation of 4.7% (v/v) of eugenol. Conclusion: Finally, the supplementation with eugenol improved the thermal stability of the essential oil of Hedychium coronarium Koening, which could be applicable to other oils thereby improving their physicochemical properties.

The Ordered Phase Formation in Ti-Al-Ga Alloys

1970 ◽  
Vol 28 ◽  
pp. 440-441
Author(s):  
Shiro Fujishiro ◽  
Harold L. Gegel
Keyword(s):  
Thermal Stability ◽  
High Temperature ◽  
Titanium Alloys ◽  
Growth Kinetics ◽  
Stoichiometric Composition ◽  
Good Potential ◽  
Alpha Titanium ◽  
Cold Rolled ◽  
Kinetics Of ◽  
Thermal Stability Of

Ordered-alpha titanium alloys having a DO19 type structure have good potential for high temperature (600°C) applications, due to the thermal stability of the ordered phase and the inherent resistance to recrystallization of these alloys. Five different Ti-Al-Ga alloys consisting of equal atomic percents of aluminum and gallium solute additions up to the stoichiometric composition, Ti3(Al, Ga), were used to study the growth kinetics of the ordered phase and the nature of its interface.The alloys were homogenized in the beta region in a vacuum of about 5×10-7 torr, furnace cooled; reheated in air to 50°C below the alpha transus for hot working. The alloys were subsequently acid cleaned, annealed in vacuo, and cold rolled to about. 050 inch prior to additional homogenization

Microstructure studies of tungsten silicide schottky contacts on Gaas

1987 ◽  
Vol 45 ◽  
pp. 328-329
Author(s):  
Yih-Cheng Shih ◽  
E. L. Wilkie
Keyword(s):  
Thermal Stability ◽  
Field Effect Transistors ◽  
Schottky Contact ◽  
Schottky Contacts ◽  
Excellent Thermal Stability ◽  
Barrier Heights ◽  
Gaas Substrates ◽  
Film Adhesion ◽  
Threshold Voltages ◽  
Thermal Stability Of

Tungsten silicides (WSix) have been successfully used as the gate materials in self-aligned GaAs metal-semiconductor-field- effect transistors (MESFET). Thermal stability of the WSix/GaAs Schottky contact is of major concern since the n+ implanted source/drain regions must be annealed at high temperatures (∼ 800°C). WSi0.6 was considered the best composition to achieve good device performance due to its low stress and excellent thermal stability of the WSix/GaAs interface. The film adhesion and the uniformity in barrier heights and ideality factors of the WSi0.6 films have been improved by depositing a thin layer of pure W as the first layer on GaAs prior to WSi0.6 deposition. Recently WSi0.1 has been used successfully as the gate material in 1x10 μm GaAs FET's on the GaAs substrates which were sputter-cleaned prior to deposition. These GaAs FET's exhibited uniform threshold voltages across a 51 mm wafer with good film adhesion after annealing at 800°C for 10 min.

Thermal stability of Al-Cu-Fe icosahedral alloys

1991 ◽  
Vol 1 (12) ◽  
pp. 1823-1836 ◽  
Author(s):  
M. Bessière ◽  
A. Quivy ◽  
S. Lefebvre ◽  
J. Devaud-Rzepski ◽  
Y. Calvayrac
Keyword(s):  
Thermal Stability ◽  
Thermal Stability Of
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