Expanding the Frequency Range and Material Applicability of Piezoelectric Shear Rheometry: An investigation of the shear mechanical response of polymers and glass-forming liquids

Mathias Mikkelsen

Expanding the Frequency Range and Material Applicability of Piezoelectric Shear Rheometry: An investigation of the shear mechanical response of polymers and glass-forming liquids

Mathias Mikkelsen

Publikation: Bog/antologi/afhandling/rapport › Ph.d.-afhandling

Abstract

Denne afhandling beskriver udviklingen, valideringen og brugen af et piezoelektrisk højfrekvens-rheometer til måling af forskydningsmodul på gummi og seje væsker. Rheometret er en videreudvikling af et tidligere udviklet apparat, kaldet piezoelectric shear gauge (PSG), som gennem de seneste årtier har været i brug i grundforskningen på Roskilde Universitets afdeling for seje væskers fysik.
I dette projekt har vi forbedret dataanalysen ud fra en ny algoritme til invertering af rådata som gør det muligt at bestemme forskydningsmodulet ved højere frekvenser end nogensinde før, udviklet en version af PSG’en som rutinemæssigt og pålideligt kan benyttes til målinger på gummi, samt måleprotokoller og metoder til disse målinger, og valideret disse nyskabelser ud fra sammenlignin-
ger med tidligere metoder og apparater. Det er derfor nu muligt at benytte PSG’en til måling af forskydningsmoduler mellem 1 MPa og 10 GPa ved frekvenser helt op til 80 kHz. Dette har vi udnyttet til studier af den mekaniske dynamik i phenylalkoholer. Disse studier viser tegn på polymerlignende strukturer som dannes ved hydrogenbindinger mellem de enkelte alkoholmolekyler. Desuden viser de en generisk form på den mekaniske α-relaksation og en stærk sammen-
hæng mellem de karakteristiske tider for de dielektriske og forskydningsmekaniske relaksationer.
Nye, simplere opbyggede, versioner af PSG’en er blevet udviklet og valideret ved sammenligning med tidligere versioner. En sådan simplere version er taget i brug til målinger på kulstoffyldt, vulkaniseret naturgummi. Resultaterne af disse bredspektrede målinger udfordrer den udbredte antagelse om et simpelt sammenfald mellem tids- og temperaturafhængigheden af den mekaniske relaksation; desuden viser de begrænsningerne ved at benytte Williams-Landel-Ferry-ligningen til at kombinere flere smalspektrede målinger som erstatning for bredspektret data.

Originalsprog	Engelsk

Udgivelsessted	Roskilde
Forlag	Roskilde Universitet
Antal sider	110
ISBN (Trykt)	978-87-7209-521-9
Status	Udgivet - 1 maj 2023

Bibliografisk note

Vejledere: Tina Hecksher & Tage Christensen
Jorge Lacayo-Pineda & Ali Karimi Continental

2 Tidsskriftartikel

Dielectric and Shear Mechanical Spectra of Propanols: The Influence of Hydrogen-Bonded Structures
Mikkelsen, M., Gabriel, J. & Hecksher, T., 2023, I: Journal of Physical Chemistry Part B: Condensed Matter, Materials, Surfaces, Interfaces & Biophysical. 127, 1, s. 371-377 7 s.
Publikation: Bidrag til tidsskrift › Tidsskriftartikel › Forskning › peer review
Piezoelectric shear rheometry: Further developments in experimental implementation and data extraction
Mikkelsen, M., Eliasen, K. L., Lindemann, N., Moch, K., Böhmer, R., Karimi, A., Lacayo-Pineda, J., Jakobsen, B., Niss, K., Christensen, T. E. & Hecksher, T., 26 aug. 2022, I: Journal of Rheology. 66, 983, s. 983-1003 21 s.
Publikation: Bidrag til tidsskrift › Tidsskriftartikel › Forskning › peer review

1 Afsluttet

Closing the Gap in Broadband Mechanical Spectroscopy — Expanding the Range of Dynamic Mechanical Analysis
Mikkelsen, M. (Projektdeltager), Lindemann, N. (Projektdeltager), Karimi, A. (Bivejleder), Christensen, T. E. (Bivejleder), Lacayo-Pineda, J. (Hovedvejleder) & Hecksher, T. (Hovedvejleder)
01/09/2019 → 30/11/2022
Projekter: Projekt › Forskning

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title = "Expanding the Frequency Range and Material Applicability of Piezoelectric Shear Rheometry: An investigation of the shear mechanical response of polymers and glass-forming liquids",

abstract = "This thesis describes the development, validation, and use of a piezoelectric high-frequency rheometer for measuring the shear modulus of rubbers and viscous liquids. The rheometer is an improvement of a previously developed device called the piezoelectric shear gauge (PSG), which has been in use for several decades at Roskilde University for fundamental research into the physics of viscous liquids.In this project, the data analysis has been improved based on a new algorithm for inverting raw data, which makes it possible to determine the shear modulus at higher frequencies than ever before. A version of the PSG has been developed that can be routinely and reliably used for measurements on rubber, as well as measurement protocols and methods for these measurements. And these innovations have been validated by comparison with previous methods and devices. It is now possible to use the PSG to measure shear moduli between 1 MPa and 10 GPa at frequencies up to 80 kHz.This has been utilized for studies of the mechanical dynamics of phenylalcohols, which show signs of polymer-like structures formed by hydrogen bonding between the alcohol molecules. The data also show a generic form of the mechanical α-relaxation and a strong correlation between the characteristic times of the dielectric and shear mechanical relaxations.New and simpler versions of the PSG have been developed and validated by comparison with previous versions. One of the new PSGs has been used for measurements on carbon black-filled, vulcanized natural rubbers. The results of these broad-spectrum measurements challenge the widespread assumption of time-temperature superposition; they also demonstrate the limitations of using the Williams-Landel-Ferry equation for the construction of broadband master curves from narrowband data.",

author = "Mathias Mikkelsen",

note = "Supervised by: Tina Hecksher & Tage Christensen Roskilde University Jorge Lacayo-Pineda & Ali Karimi Continental",

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T2 - An investigation of the shear mechanical response of polymers and glass-forming liquids

AU - Mikkelsen, Mathias

N1 - Supervised by: Tina Hecksher & Tage Christensen Roskilde University Jorge Lacayo-Pineda & Ali Karimi Continental

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N2 - This thesis describes the development, validation, and use of a piezoelectric high-frequency rheometer for measuring the shear modulus of rubbers and viscous liquids. The rheometer is an improvement of a previously developed device called the piezoelectric shear gauge (PSG), which has been in use for several decades at Roskilde University for fundamental research into the physics of viscous liquids.In this project, the data analysis has been improved based on a new algorithm for inverting raw data, which makes it possible to determine the shear modulus at higher frequencies than ever before. A version of the PSG has been developed that can be routinely and reliably used for measurements on rubber, as well as measurement protocols and methods for these measurements. And these innovations have been validated by comparison with previous methods and devices. It is now possible to use the PSG to measure shear moduli between 1 MPa and 10 GPa at frequencies up to 80 kHz.This has been utilized for studies of the mechanical dynamics of phenylalcohols, which show signs of polymer-like structures formed by hydrogen bonding between the alcohol molecules. The data also show a generic form of the mechanical α-relaxation and a strong correlation between the characteristic times of the dielectric and shear mechanical relaxations.New and simpler versions of the PSG have been developed and validated by comparison with previous versions. One of the new PSGs has been used for measurements on carbon black-filled, vulcanized natural rubbers. The results of these broad-spectrum measurements challenge the widespread assumption of time-temperature superposition; they also demonstrate the limitations of using the Williams-Landel-Ferry equation for the construction of broadband master curves from narrowband data.

AB - This thesis describes the development, validation, and use of a piezoelectric high-frequency rheometer for measuring the shear modulus of rubbers and viscous liquids. The rheometer is an improvement of a previously developed device called the piezoelectric shear gauge (PSG), which has been in use for several decades at Roskilde University for fundamental research into the physics of viscous liquids.In this project, the data analysis has been improved based on a new algorithm for inverting raw data, which makes it possible to determine the shear modulus at higher frequencies than ever before. A version of the PSG has been developed that can be routinely and reliably used for measurements on rubber, as well as measurement protocols and methods for these measurements. And these innovations have been validated by comparison with previous methods and devices. It is now possible to use the PSG to measure shear moduli between 1 MPa and 10 GPa at frequencies up to 80 kHz.This has been utilized for studies of the mechanical dynamics of phenylalcohols, which show signs of polymer-like structures formed by hydrogen bonding between the alcohol molecules. The data also show a generic form of the mechanical α-relaxation and a strong correlation between the characteristic times of the dielectric and shear mechanical relaxations.New and simpler versions of the PSG have been developed and validated by comparison with previous versions. One of the new PSGs has been used for measurements on carbon black-filled, vulcanized natural rubbers. The results of these broad-spectrum measurements challenge the widespread assumption of time-temperature superposition; they also demonstrate the limitations of using the Williams-Landel-Ferry equation for the construction of broadband master curves from narrowband data.

M3 - Ph.D. thesis

SN - 978-87-7209-521-9

BT - Expanding the Frequency Range and Material Applicability of Piezoelectric Shear Rheometry

PB - Roskilde Universitet

CY - Roskilde

ER -

Expanding the Frequency Range and Material Applicability of Piezoelectric Shear Rheometry: An investigation of the shear mechanical response of polymers and glass-forming liquids

Abstract

Bibliografisk note

Publikation

Dielectric and Shear Mechanical Spectra of Propanols: The Influence of Hydrogen-Bonded Structures

Piezoelectric shear rheometry: Further developments in experimental implementation and data extraction

Projekter

Closing the Gap in Broadband Mechanical Spectroscopy — Expanding the Range of Dynamic Mechanical Analysis

Citer dette