1H-NMR Spectroscopy: A Possible Approach to Advanced Bitumen Characterization for Industrial and Paving Applications

Cesare Oliviero Rossi,Giuseppina De Luca,Cesare Sangiorgi,Paolino Caputo,Loredana Maiuolo,Shahin Eskandarsefat

doi:10.3390/app8020229

Cesare Oliviero Rossi, Giuseppina De Luca + Show 4 more

Open Access

https://doi.org/10.3390/app8020229

Copy DOI

Journal: Applied sciences	Publication Date: Feb 2, 2018
Citations: 42	License type: CC BY 4.0

Affiliation: University of Calabria, University of Bologna

Abstract

Bitumen has unique chemo-mechanical properties, and for this reason, it is today one of the main constituents of many industrial products beside its common use in highway pavements construction. While the excellent rheological properties of bitumens have been investigated by means of different techniques, much remains to be known about the intrinsic properties of this complex material. It is therefore important to investigate its structure and properties from a closer point of view, towards possible useful modifications of the neat material. The present research developed a technique to investigate the composition of bitumens using Thin Layer Chromatography (TLC) to separate the different fractions, and Nuclear Magnetic Resonance (NMR) spectroscopy to assess and quantify the aliphatic hydrogen part with respect to the aromatic part. To achieve a comprehensive understanding of the chemical composition of the materials, Proton Nuclear Magnetic Resonance (1H-NMR) analysis was conducted in solution, using CCl4 as solvent, on three different neat bitumens and on their asphaltene and maltene fractions. The combined application of TLC and 1H-NMR spectroscopy enables the advanced characterization of bitumens supplied from different sources or obtained from different processes. This further allows addressing the use of specific modifications according to the bitumen final applications.

Highlights

As one of the materials obtained from crude oil, is a viscoelastic material, which is remarkably soluble in carbon disulfide (CS2 ) and holds adhesive and waterproofing properties
Considering the chemical composition, it is highly dependent on the source and on the refinery process, which contribute to its unique chemical and physical properties [2]
Since the properties of bitumen and its use largely depend on its chemical composition, it is clear that significant improvements would result from a better understanding of the material at its molecular level

Summary

Introduction

As one of the materials obtained from crude oil, is a viscoelastic material, which is remarkably soluble in carbon disulfide (CS2 ) and holds adhesive and waterproofing properties. Considering the chemical composition, it is highly dependent on the source (crude oil) and on the refinery process, which contribute to its unique chemical and physical properties [2]. In this context chemistry of bitumen has been considered as a key parameter in fundamental understanding of bitumen characterization, the knowledge about such a complex material is still limited. Bitumen is typically constituted of two main groups of compounds: (a) asphaltenes, defined as n-heptane-insoluble and toluene-soluble part, Appl.

Objectives

Results

Conclusion