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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...
Autores principales: | , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
MDPI
2022
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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. |
format | Online Article Text |
id | pubmed-9267750 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2022 |
publisher | MDPI |
record_format | MEDLINE/PubMed |
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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