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Apparent Molecular Weight Distributions in Bituminous Binders

Molecular weight distributions are widely used to evaluate the effects of aging or modifiers in bituminous binders. As with polymers, the most common techniques to obtain the distributions can be subdivided into two main groups, depending on whether or not they use a solvent. In the first group, the...

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Autores principales: Polacco, Giovanni, Cappello, Miriam, Cuciniello, Giacomo, Filippi, Sara
Formato: Online Artículo Texto
Lenguaje:English
Publicado: MDPI 2022
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9267750/
https://www.ncbi.nlm.nih.gov/pubmed/35806824
http://dx.doi.org/10.3390/ma15134700
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author Polacco, Giovanni
Cappello, Miriam
Cuciniello, Giacomo
Filippi, Sara
author_facet Polacco, Giovanni
Cappello, Miriam
Cuciniello, Giacomo
Filippi, Sara
author_sort Polacco, Giovanni
collection PubMed
description Molecular weight distributions are widely used to evaluate the effects of aging or modifiers in bituminous binders. As with polymers, the most common techniques to obtain the distributions can be subdivided into two main groups, depending on whether or not they use a solvent. In the first group, the dimension of the molecules is evaluated in a diluted unperturbed state, while, in the second, the dimension derives from the bulk, where aggregated or interacting molecules may behave as single entities. However, the calibration curves used in the bulk are tuned in order to homogenize the results derived from the two approaches. This sort of contradiction, plus the high number of experimental uncertainties, suggest that the term “apparent” should be used for both distributions. These aspects are well known in the field of polymers but have received less attention in the case of bitumens, which are even more complex. This paper pinpoints the advantages and disadvantages of the two techniques, thus highlighting the most appropriate use. Bulk methods are preferred when evaluating properties that are strictly dependent on the microstructure, such as the level of aging and the effects of additives or modifiers. Diluted methods should be used when the molecular size matters, such as in quantifying the presence of polymers or rejuvenators. Both techniques should be used for comparative studies only.
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spelling pubmed-92677502022-07-09 Apparent Molecular Weight Distributions in Bituminous Binders Polacco, Giovanni Cappello, Miriam Cuciniello, Giacomo Filippi, Sara Materials (Basel) Review Molecular weight distributions are widely used to evaluate the effects of aging or modifiers in bituminous binders. As with polymers, the most common techniques to obtain the distributions can be subdivided into two main groups, depending on whether or not they use a solvent. In the first group, the dimension of the molecules is evaluated in a diluted unperturbed state, while, in the second, the dimension derives from the bulk, where aggregated or interacting molecules may behave as single entities. However, the calibration curves used in the bulk are tuned in order to homogenize the results derived from the two approaches. This sort of contradiction, plus the high number of experimental uncertainties, suggest that the term “apparent” should be used for both distributions. These aspects are well known in the field of polymers but have received less attention in the case of bitumens, which are even more complex. This paper pinpoints the advantages and disadvantages of the two techniques, thus highlighting the most appropriate use. Bulk methods are preferred when evaluating properties that are strictly dependent on the microstructure, such as the level of aging and the effects of additives or modifiers. Diluted methods should be used when the molecular size matters, such as in quantifying the presence of polymers or rejuvenators. Both techniques should be used for comparative studies only. MDPI 2022-07-05 /pmc/articles/PMC9267750/ /pubmed/35806824 http://dx.doi.org/10.3390/ma15134700 Text en © 2022 by the authors. https://creativecommons.org/licenses/by/4.0/Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/).
spellingShingle Review
Polacco, Giovanni
Cappello, Miriam
Cuciniello, Giacomo
Filippi, Sara
Apparent Molecular Weight Distributions in Bituminous Binders
title Apparent Molecular Weight Distributions in Bituminous Binders
title_full Apparent Molecular Weight Distributions in Bituminous Binders
title_fullStr Apparent Molecular Weight Distributions in Bituminous Binders
title_full_unstemmed Apparent Molecular Weight Distributions in Bituminous Binders
title_short Apparent Molecular Weight Distributions in Bituminous Binders
title_sort apparent molecular weight distributions in bituminous binders
topic Review
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9267750/
https://www.ncbi.nlm.nih.gov/pubmed/35806824
http://dx.doi.org/10.3390/ma15134700
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