Compositional and Structural Characterization of Waxes Isolated from Bitumens

Lu, Xionggang; Redelius, Per

doi:10.1021/ef0503414

Cited by 72 publications

(32 citation statements)

References 14 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Several studies found self-ordering behavior for such molecules and it has been proven that this effect, which is caused by p-p interactions, can also be found in asphaltenes [2,12,13,19,20,55,59,62]. For most bitumina studied in literature, the natural wax fraction is below 2 wt% as measured by standard distillation methods [32], while the typical asphaltene content is around 10 wt%.…”

Section: Discussionmentioning

confidence: 98%

“…Detailed studies of waxes in bitumen have shown that these are largely dominated by n-alkanes and isoalkanes with carbon numbers of C15-C57 [32], and melting points of around 40-65°C. Furthermore, a recently concluded round-robin test focused the glass transition temperature reliability via DSC testing and found that the addition of 3 wt% wax had no significant influence on the glass transition temperature (T g ) of bitumen [51], limiting the calculation of wax content by DSC.…”

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

The bitumen microstructure: a fluorescent approach

et al. 2014

View full text Add to dashboard Cite

Five bituminous samples were carefully studied by confocal laser scanning microscopy using 488 nm excitation radiation and observing 500-530 nm of emission. The images revealed the microstructure of bitumen. The influence of the admixture of mineral aggregates concerning the microstructure was tested. For the minerals, no significant influence was found. For understanding the origin of fluorescent signals, the samples were separated into asphaltenes and maltenes and analyzed with fluorescence spectroscopy. Although former works have assumed the origin of fluorescent emissions in bitumen to be found in the asphaltene fraction, the asphaltenes produce little to no emissions, but the maltenes exhibit strong fluorescence in the observed spectral region. For deeper insight, fractionation of the bitumina into the SARA fractions by chromatographic column separation was necessary. The fluorescence spectra of these fractions were analyzed and revealed the aromatics and resin phases to be the only components capable of sufficiently intense fluorescent emission. This is a strong argument for a complex internal microstructure consisting of a mantle of aromatics surrounding an inner core.

show abstract

Section: Discussionmentioning

confidence: 98%

Section: Discussionmentioning

confidence: 99%

The bitumen microstructure: a fluorescent approach

et al. 2014

View full text Add to dashboard Cite

show abstract

“…For this study, bitumen of 70/100 penetration grade was selected which contains 5.4 % of wax measured by Differential Scanning Calorimetry (DSC) [21]. The other physical properties of the bitumen are as follows: penetration 72dmm (EN1426), softening point 50.8°C (EN1427), dynamic viscosity 94 Pa s (EN12596), kinetic viscosity 124 mm 2 /s (EN12595) and fraass breaking point -7°C (EN12593).…”

Section: Micro-scale Investigationmentioning

confidence: 99%

On the oxidative ageing mechanism and its effect on asphalt mixtures morphology

et al. 2014

View full text Add to dashboard Cite

This paper investigates the influence of mixture morphologies and microstructures on oxidative ageing of asphalt mixtures. For this, an oxidative ageing mechanism based on a diffusion-reaction process was developed. Previously, most asphalt oxidative ageing modeling research focused on unidirectional diffusion of continuous oxygen flow through bitumen films, which is far from the actual boundary conditions in asphalt mixtures. For this reason in the current study, a finite element (FE) analysis has been conducted in which 3D mixture morphology was considered. Mixture morphology is the combination of mineral aggregate packing, porosity, air-void distribution and their interconnectivity. One dense and one open graded field asphalt mixture core were scanned with a computerized tomography X-ray scanner. In the analyses, the developed oxidative ageing model was implemented. The FE analysis showed that the effect of the air-void distribution, their interconnectivity and the mineral aggregate packing has a significant effect on the resulting age hardening of the overall mixture. Furthermore, from the microstructural investigation done in this research, strong indications were found that, depending on the bitumen and its conditioning, water soluble thin films are formed due to ageing. This means that ageing and moisture damage are strongly interlinked and this should thus be considered in the design of the asphaltic materials and the prediction of their long term performance.

show abstract

“…Gas chromatography offers, however, much better separation of alkanes (i.e., one base line separated peak for each alkane) until carbon number C50. [15] Interactive Liquid Chromatography of Alkanes Many groups have measured the retention of alkanes on sorbents in various liquids ( Table 2 and 3). The alkanes have been dissolved usually in a single solvent and separated most often at room temperature.…”

Section: Sec Mode Of Alkanesmentioning

confidence: 99%

Liquid Chromatographic Separation of Olefin Oligomers and its Relation to Separation of Polyolefins – an Overview

Macko¹,

Pasch

Wang

2009

Macromolecular Symposia

View full text Add to dashboard Cite

Linear and branched alkanes are oligomers of polyethylene. Alkanes with higher molar masses are called waxes. These substances are widely used as fuels, oils, lubricants, etc. and for these reasons many groups have tried to analyse, separate and characterise alkanes by various methods, including liquid chromatography. Alkanes may be separated according to their size in solution by SEC. In addition to chromatographic systems separating in the SEC mode, various sorbent-solvent systems have been published, where alkanes have been separated one from another by adsorption and/or precipitation mechanism. The mobile phase is either a nonpolar solvent or a polar solvent or a mixture of a solvent and a non-solvent for alkanes. Even near critical conditions, which have several advantages for applications of HPLC in polymer analysis, have been identified for alkanes. Moreover, selective separations of branched alkanes according to their structure have been published. In the majority of these published studies, solvents with low boiling points have been used as the mobile phases, which do not allow dissolution of crystalline polyolefins at atmospheric pressure. However, taking into account experiences with the separation of alkanes, new HPLC systems for the separation of polyolefins may be developed. This is a major challenge and first results are presented in this contribution.

show abstract

Compositional and Structural Characterization of Waxes Isolated from Bitumens

Cited by 72 publications

References 14 publications

The bitumen microstructure: a fluorescent approach

The bitumen microstructure: a fluorescent approach

On the oxidative ageing mechanism and its effect on asphalt mixtures morphology

Liquid Chromatographic Separation of Olefin Oligomers and its Relation to Separation of Polyolefins – an Overview

Contact Info

Product

Resources

About