Title
FT-IR mapping as a novel tool for assessing the compatibility of bitumen and SBS copolymer
Authors
[ 1 ] Instytut Budownictwa, Wydział Inżynierii Lądowej i Transportu, Politechnika Poznańska | [ 2 ] Instytut Technologii i Inżynierii Chemicznej, Wydział Technologii Chemicznej, Politechnika Poznańska | [ P ] employee
Scientific discipline (Law 2.0)
[2.7] Civil engineering, geodesy and transport[7.6] Chemical sciences
Year of publication
2025
Published in
Article type
scientific article
Publication language
english
Keywords
Abstract
EN The durability and performance of polymer-modified bitumen (PMB) are critically influenced by the compatibility between the base binder and polymer, with storage stability being a decisive factor for both laboratory evaluation and field application. Conventional tests, such as difference in softening point and penetration after the storage stability test (tube test), are widely applied to detect incompatibility; however, they offer limited insight into the microstructural distribution of polymers within the bitumen matrix. This study aims to investigate the potential of Fourier-transform infrared (FT-IR) mapping as an advanced analytical method for assessing the compatibility of styrene–butadiene–styrene (SBS)-modified bitumens. Two paving-grade binders (160/220 and 35/50) were modified with three SBS copolymers of different molecular structures–linear, radial, and high-vinyl–at concentrations ranging from 2 % to 10 %. The results demonstrated that FT-IR mapping effectively identified phase separation and polymer gradients, confirming observations from standardized storage stability tests. In contrast, group composition analysis of bitumen fractions revealed statistically significant changes after storage but proved to be of limited predictive value for compatibility. The findings further indicated that storage stability depends not only on polymer dosage but also on the colloidal instability index (CII) of the base binder and the molecular architecture of the SBS copolymer. Overall, FT-IR mapping proved to be a powerful diagnostic tool, enabling spatially resolved evaluation of polymer distribution, and thus offering significant potential for improving the design, optimization, and long-term performance of polymer-modified bitumens.
Date of online publication
02.12.2025
Pages (from - to)
144735-1 - 144735-16
Comments
Article Number: 144735
Ministry points / journal
140
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