Relationship between Chemical Structures and Weatherability of Coating Asphalts as Shown by Infrared Absorption Spectroscopy

Smith, Clara D.; Schuetz, C C; Hodgson, R S

doi:10.1021/i360018a013

Cited by 18 publications

(3 citation statements)

References 3 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The low-temperature physical and rheological properties of asphalts are of interest because low-temperature cracking is one of the primary modes of failure for asphalt pavements. At the molecular level, this type of failure mode has been attributed, in part, to crystalline waxes.The first evidence of a crystalline phase in asphalts was reported in 1966 by Smith et al using infrared spectroscopy. These authors found that the 720 cm -1 band for amorphous methylene carbons in long-chain hydrocarbons split into a doublet in waxy asphalts.…”

Section: Introductionmentioning

confidence: 99%

A ¹³C NMR and DSC Study of the Amorphous and Crystalline Phases in Asphalts

Michon¹,

Netzel²,

Turner³

et al. 1999

Energy Fuels

View full text Add to dashboard Cite

The amorphous and crystalline phases in asphalt have been identified and studied using lowtemperature solid-state carbon-13 CP/MAS NMR and DSC techniques. The NMR mass percent of the crystalline methylene carbons was shown to correlate linearly with the mass percent of crystalline wax in asphalts measured using DSC. While the internal methylene carbon content of long-chain alkanes in the crystalline phase in the asphalts varied, the internal methylene carbon content of the long-chain alkanes in the amorphous phase remained relatively constant. The NMR crystalline methylene carbon content was plotted against a low-temperature cracking parameter, the fracture temperature of an asphalt. It was found that 1% or less of aliphatic carbons in the crystalline phase has little effect on the fracture temperature. For these asphalts, the fracture temperature depends mainly on the initial amount of mobile aliphatic carbons in the amorphous phase at 23°C. For asphalts containing 1% or more of crystalline aliphatic carbons, the fracture temperature increases with increasing crystalline methylene carbon content.

show abstract

Section: Introductionmentioning

confidence: 99%

A ¹³C NMR and DSC Study of the Amorphous and Crystalline Phases in Asphalts

Michon¹,

Netzel²,

Turner³

et al. 1999

Energy Fuels

View full text Add to dashboard Cite

show abstract

“…33 The application of FT-IR to determine the phase transformations of waxes in oils, and in particular the determination of WAT, began with four papers as cited. 34–37 By analogy with the measurement of the crystallinity of polyethylene, 38 the bands of rocking vibrations (region 735–715 cm –1 ) were used to determine the phase transition of waxes. It was shown that there are correlations of peak intensity with temperature, which are characteristics of phase transitions, and this was in good agreement with the DSC data.…”

Section: Introductionmentioning

confidence: 99%

Features of Wax Appearance Temperature Determination of Waxy Crude Oil Using Attenuated Total Reflection Fourier Transform Infrared Spectroscopy Under Ambient and High Pressure

Shalygin,

Kozhevnikov,

Morozov

et al. 2023

Appl Spectrosc

View full text Add to dashboard Cite

The wax appearance temperature (WAT), being one of the key characteristics of waxy crude oil and other waxy substances, is used for the necessary assessment of the phase stability of materials during various technological processes. However, the determination of this parameter as well as peculiarities of wax formation under high gas pressure suffers from the lack of suitable techniques for this task. To address this issue, an attenuated total reflection Fourier transform infrared spectroscopy (ATR FT-IR) method has been applied for the first time to measure the WAT of waxy crude oil under high gas pressure. Carbon dioxide (CO2), nitrogen, and natural gas were used in the study due to their widespread applicability as injection gases in enhanced oil recovery methods. The S2/S1 versus temperature method based on changes in the band of rocking vibrations of the CH2 group was applied to determine WAT. It was found that the ATR FT-IR method based on the proposed dependence S2/S1 versus temperature gives lower WAT values compared to those observed by viscometry, magnetic resonance imaging inspection, and cross-polarized microscopy methods for the waxy crude oil studied. A detailed analysis was carried out using variable-temperature ATR FT-IR spectra of waxy crude oil in the temperature region near the WAT. Essentially different dynamics of wax crystal formation in waxy oil sample and model paraffin solution were demonstrated during the cooling process. The results obtained by high-pressure ATR FT-IR showed that CO2 and natural gas reduce the WAT, while nitrogen has virtually no effect. In addition, for the studied oil, it was found that high pressure of CO2 and natural gases leads to a visual decrease in the amount of wax crystals precipitated, but not to the complete disappearance of microcrystals at a certain temperature and pressure. The results obtained proved that ATR FT-IR can be an effective method for proper determinations of WAT under high-pressure conditions similar to those met in practice.

show abstract

“…Infrared (IR) spectroscopy has been previously used to identify solid−solid and solid−liquid-phase transitions for alkanes , and petroleum waxes, to measure crystallinity and its temperature dependence for polyethylene (PE), and as an indicator of methylene crystallinity in petroleum-derived asphalts . IR spectroscopy measures the absorbance associated with molecular vibrations present in the sample analyzed.…”

Section: Introductionmentioning

confidence: 99%

Determination of Wax Precipitation Temperature and Amount of Precipitated Solid Wax versus Temperature for Crude Oils Using FT-IR Spectroscopy

Roehner

Hanson

2001

Energy Fuels

View full text Add to dashboard Cite

Wax precipitation in crude oils can produce problems in production and transportation operations. A novel FT-IR spectroscopy method is described for the determination of the wax precipitation temperature (WPT), and the estimation of the amount of precipitated solid wax material (both crystalline and amorphous) present in petroleum crude oils. A reference model oil system is analyzed using the described method. Comparisons are provided between FT-IR generated data and data generated using conventional analyses for Alaska North Slope, Utah, and Gulf of Mexico crude oils. The FT-IR method is shown to provide comparative results with conventional analysis methods, and offers several advantages over existing test methods.

show abstract

Relationship between Chemical Structures and Weatherability of Coating Asphalts as Shown by Infrared Absorption Spectroscopy

Cited by 18 publications

References 3 publications

A ¹³C NMR and DSC Study of the Amorphous and Crystalline Phases in Asphalts

A ¹³C NMR and DSC Study of the Amorphous and Crystalline Phases in Asphalts

Features of Wax Appearance Temperature Determination of Waxy Crude Oil Using Attenuated Total Reflection Fourier Transform Infrared Spectroscopy Under Ambient and High Pressure

Determination of Wax Precipitation Temperature and Amount of Precipitated Solid Wax versus Temperature for Crude Oils Using FT-IR Spectroscopy

Contact Info

Product

Resources

About

Relationship between Chemical Structures and Weatherability of Coating Asphalts as Shown by Infrared Absorption Spectroscopy

Cited by 18 publications

References 3 publications

A 13C NMR and DSC Study of the Amorphous and Crystalline Phases in Asphalts

A 13C NMR and DSC Study of the Amorphous and Crystalline Phases in Asphalts

Features of Wax Appearance Temperature Determination of Waxy Crude Oil Using Attenuated Total Reflection Fourier Transform Infrared Spectroscopy Under Ambient and High Pressure

Determination of Wax Precipitation Temperature and Amount of Precipitated Solid Wax versus Temperature for Crude Oils Using FT-IR Spectroscopy

Contact Info

Product

Resources

About

A ¹³C NMR and DSC Study of the Amorphous and Crystalline Phases in Asphalts

A ¹³C NMR and DSC Study of the Amorphous and Crystalline Phases in Asphalts