Analysis of the relaxation and retardation spectra obtained from the double-log representation of the viscoelastic functions

Relaxation or retardation distribution functions are sometimes used to determine the molecular models of the polymeric structure of a linear viscoelastic material. These spectra are usually calculated from the double-log representation of any mechanical property, using approximation methods. In this...

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Detalles Bibliográficos
Autores principales:	Povolo, F., Hermida, ȁ.B.
Formato:	JOUR
Materias:	Double-Log representation Master curve Re-laxation and retardation spectra Viscoelastic functions Mathematical Techniques - Approximation Theory Polymers - Molecular Structure Relaxation Processes - Analysis Spectrum Analysis - Applications Double Log Representation Master Curve Relaxation and Retardation Spectra Viscoelastic Functions Polymers
Acceso en línea:	http://hdl.handle.net/20.500.12110/paper_00323896_v24_n1_p15_Povolo
Aporte de:	Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) de Universidad de Buenos Aires

id	todo:paper_00323896_v24_n1_p15_Povolo
record_format	dspace
spelling	todo:paper_00323896_v24_n1_p15_Povolo2023-10-03T14:45:15Z Analysis of the relaxation and retardation spectra obtained from the double-log representation of the viscoelastic functions Povolo, F. Hermida, ȁ.B. Double-Log representation Master curve Re-laxation and retardation spectra Viscoelastic functions Mathematical Techniques - Approximation Theory Polymers - Molecular Structure Relaxation Processes - Analysis Spectrum Analysis - Applications Double Log Representation Master Curve Relaxation and Retardation Spectra Viscoelastic Functions Polymers Relaxation or retardation distribution functions are sometimes used to determine the molecular models of the polymeric structure of a linear viscoelastic material. These spectra are usually calculated from the double-log representation of any mechanical property, using approximation methods. In this paper it is shown that the double-log plots distort the viscoelastic behavior, leading to spectra that do not describe the real mechanical response. To solve this problem, a normalized representation of the measurements is proposed and its improvements are discussed in detail. Particularly, the retardation spectrum determined from the normalized dynamic compliance of polyisobutylene is taken as an example, showing some inconsistencies in the model determined from the double-log representation. Finally, even with the normalized representation, the spectra derived from the master curves do not always provide a good fitting of these curves. Hence, it is pointed out that the analysis of individual curves measured over several decades of time or frequency leads to a better determination of the real distribution function of characteristic times. © 1992 The Society of Polymer Science, Japan. JOUR info:eu-repo/semantics/openAccess http://creativecommons.org/licenses/by/2.5/ar http://hdl.handle.net/20.500.12110/paper_00323896_v24_n1_p15_Povolo
institution	Universidad de Buenos Aires
institution_str	I-28
repository_str	R-134
collection	Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA)
topic	Double-Log representation Master curve Re-laxation and retardation spectra Viscoelastic functions Mathematical Techniques - Approximation Theory Polymers - Molecular Structure Relaxation Processes - Analysis Spectrum Analysis - Applications Double Log Representation Master Curve Relaxation and Retardation Spectra Viscoelastic Functions Polymers
spellingShingle	Double-Log representation Master curve Re-laxation and retardation spectra Viscoelastic functions Mathematical Techniques - Approximation Theory Polymers - Molecular Structure Relaxation Processes - Analysis Spectrum Analysis - Applications Double Log Representation Master Curve Relaxation and Retardation Spectra Viscoelastic Functions Polymers Povolo, F. Hermida, ȁ.B. Analysis of the relaxation and retardation spectra obtained from the double-log representation of the viscoelastic functions
topic_facet	Double-Log representation Master curve Re-laxation and retardation spectra Viscoelastic functions Mathematical Techniques - Approximation Theory Polymers - Molecular Structure Relaxation Processes - Analysis Spectrum Analysis - Applications Double Log Representation Master Curve Relaxation and Retardation Spectra Viscoelastic Functions Polymers
description	Relaxation or retardation distribution functions are sometimes used to determine the molecular models of the polymeric structure of a linear viscoelastic material. These spectra are usually calculated from the double-log representation of any mechanical property, using approximation methods. In this paper it is shown that the double-log plots distort the viscoelastic behavior, leading to spectra that do not describe the real mechanical response. To solve this problem, a normalized representation of the measurements is proposed and its improvements are discussed in detail. Particularly, the retardation spectrum determined from the normalized dynamic compliance of polyisobutylene is taken as an example, showing some inconsistencies in the model determined from the double-log representation. Finally, even with the normalized representation, the spectra derived from the master curves do not always provide a good fitting of these curves. Hence, it is pointed out that the analysis of individual curves measured over several decades of time or frequency leads to a better determination of the real distribution function of characteristic times. © 1992 The Society of Polymer Science, Japan.
format	JOUR
author	Povolo, F. Hermida, ȁ.B.
author_facet	Povolo, F. Hermida, ȁ.B.
author_sort	Povolo, F.
title	Analysis of the relaxation and retardation spectra obtained from the double-log representation of the viscoelastic functions
title_short	Analysis of the relaxation and retardation spectra obtained from the double-log representation of the viscoelastic functions
title_full	Analysis of the relaxation and retardation spectra obtained from the double-log representation of the viscoelastic functions
title_fullStr	Analysis of the relaxation and retardation spectra obtained from the double-log representation of the viscoelastic functions
title_full_unstemmed	Analysis of the relaxation and retardation spectra obtained from the double-log representation of the viscoelastic functions
title_sort	analysis of the relaxation and retardation spectra obtained from the double-log representation of the viscoelastic functions
url	http://hdl.handle.net/20.500.12110/paper_00323896_v24_n1_p15_Povolo
work_keys_str_mv	AT povolof analysisoftherelaxationandretardationspectraobtainedfromthedoublelogrepresentationoftheviscoelasticfunctions AT hermidaab analysisoftherelaxationandretardationspectraobtainedfromthedoublelogrepresentationoftheviscoelasticfunctions
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Analysis of the relaxation and retardation spectra obtained from the double-log representation of the viscoelastic functions

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