On the thermogravimetric analysis of polymers: Polyethylene oxide powder and nanofibers

1971 ◽

Vol 29 ◽

pp. 448-449

Author(s):

G. G. Cocks ◽

C. E. Cluthe

Keyword(s):

Aqueous Solution ◽

Polyethylene Oxide ◽

Liquid Nitrogen Temperature ◽

Ice Crystals ◽

Etching Technique ◽

Structural Constituent ◽

Cryoprotective Agents ◽

Quick Freezing ◽

Freeze Etching ◽

Fractured Surface

The freeze etching technique is potentially useful for examining dilute solutions or suspensions of macromolecular materials. Quick freezing of aqueous solutions in Freon or propane at or near liquid nitrogen temperature produces relatively large ice crystals and these crystals may damage the structures to be examined. Cryoprotective agents may reduce damage to the specimem, hut their use often results in the formation of a different set of specimem artifacts.In a study of the structure of polyethylene oxide gels glycerol and sucrose were used as cryoprotective agents. The experiments reported here show some of the structures which can appear when these cryoprotective agents are used.Figure 1 shows a fractured surface of a frozen 25% aqueous solution of sucrose. The branches of dendritic ice crystals surrounded hy ice-sucrose eutectic can be seen. When this fractured surface is etched the ice in the dendrites sublimes giving the type of structure shown in Figure 2. The ice-sucrose eutectic etches much more slowly. It is the smooth continuous structural constituent surrounding the branches of the dendrites.

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Purity Evaluation of Single-Walled Carbon Nanotubes Using Thermogravimetric Analysis

Korean Journal of Metals and Materials ◽

10.3365/kjmm.2013.51.2.137 ◽

2013 ◽

Vol 51 (2) ◽

pp. 137-144

Author(s):

Naesung Lee ◽

Jeung Choon Goak ◽

Tae Yang Kim ◽

Jongwan Jung ◽

Young-Soo Seo ◽

...

Keyword(s):

Carbon Nanotubes ◽

Thermogravimetric Analysis ◽

Single Walled Carbon Nanotubes ◽

Single Walled Carbon ◽

Purity Evaluation ◽

Walled Carbon Nanotubes

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THERMOGRAVIMETRIC ANALYSIS OF THE (FeCoZr)x(CaF2)(100–x) NANOCOMPOSITE

High Temperature Material Processes An International Quarterly of High-Technology Plasma Processes ◽

10.1615/hightempmatproc.2018025484 ◽

2017 ◽

Vol 21 (4) ◽

pp. 289-298 ◽

Cited By ~ 1

Author(s):

Vitalii Bondariev ◽

Pawel Zukowski ◽

V. G. Luhin ◽

I. V. Voitov

Keyword(s):

Thermogravimetric Analysis

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Niobium Oxide as Catalyst for the Pyrolysis of Polypropylene and Polyethylene Plastic Waste

Chemistry & Chemical Technology ◽

10.23939/chcht10.04.465 ◽

2016 ◽

Vol 10 (4) ◽

pp. 465-472 ◽

Cited By ~ 2

Author(s):

Debora Almeida ◽

◽

Maria de Fatima Marques ◽

Keyword(s):

Thermogravimetric Analysis ◽

Niobium Oxide ◽

Plastic Waste

In the present work, the pyrolysis of polypropylene and polyethylene was evaluated with and without the addition of niobium oxide as catalyst by means of thermogravimetric analysis and experiments in a glass reactor. The results revealed that niobium oxide performed well in the pyrolysis of both polypropylene and polyethylene separately. For the mixture of polypropylene with polyethylene, the catalyst reduced the pyrolysis time.

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Thermal Stability of N-Heterocycle-Stabilized Iodanes – A Systematic Investigation

10.26434/chemrxiv.8964848 ◽

2019 ◽

Author(s):

Andreas Boelke ◽

Yulia A. Vlasenko ◽

Mekhman S. Yusubov ◽

Boris Nachtsheim ◽

Pavel Postnikov

Keyword(s):

Thermal Stability ◽

Differential Scanning Calorimetry ◽

Thermogravimetric Analysis ◽

Systematic Investigation ◽

Scanning Calorimetry ◽

Thermal Stability Of

The thermal stability of pseudocyclic and cyclic N-heterocycle-stabilized (hydroxy)aryl- and mesityl(aryl)-l3-iodanes (NHIs) through thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) is investigated. NHIs bearing N-heterocycles with a high N/C-ratio such as triazoles show among the lowest descomposition temperatures and the highest decomposition energies. A comparison of NHIs with known (pseudo)cyclic benziodoxolones is made and we further correlated their thermal stability with reactivity in a model oxygenation.

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