Mutual and Thermal Diffusivities in Polystyrene Melts with Dissolved Nitrogen by Dynamic Light Scattering

Piszko M, Schaible T, Bonten C, Fröba AP (2021)

Publication Language: English

Publication Status: Published

Publication Type: Journal article, Original article

Publication year: 2021

Journal

Macromolecules American Chemical Society

Publisher: American Chemical Society

Book Volume: 54

Pages Range: 5662–5672

Journal Issue: 12

DOI: 10.1021/acs.macromol.1c00819

Abstract

Knowledge on diffusion coefficients in mixtures consisting of a polymer melt and a blowing agent is necessary for understanding and characterizing the bubble growth processes during foaming of thermoplastic polymers. Due to the lack of reliable literature data in process-relevant conditions, the diffusion coefficients are often assumed to be constant to solve the equations for bubble growth in polymer melts. This study demonstrates, for the first time, the applicability of dynamic light scattering for the characterization of molecular mass and thermal transport in binary mixtures consisting of a macromolecular polymer and a dissolved gas by the determination of mutual and thermal diffusivities in macroscopic thermodynamic equilibrium. In the present study, a mixture of polystyrene and nitrogen was selected as the model system, which has technical relevance. After evidencing that the obtained experimental signals are associated with hydrodynamic modes, the influence of pressure and temperature on mutual and thermal diffusivities is discussed and the results are compared with the literature. For the mixtures studied in this work, expanded experimental uncertainties (k = 2) of the obtained diffusivities have a minimum value close to 3% and are on average 13% for the thermal diffusivity and 7.4% for the mutual diffusivity.

Authors with CRIS profile

Maximilian Piszko Institute of Advanced Optical Technologies - Thermophysical Properties (AOT-TP) Andreas Paul Fröba Institute of Advanced Optical Technologies - Thermophysical Properties (AOT-TP)

Additional Organisation(s)

Erlangen Graduate School in Advanced Optical Technologies

Involved external institutions

Universität Stuttgart DE Germany (DE)

How to cite

APA:

Piszko, M., Schaible, T., Bonten, C., & Fröba, A.P. (2021). Mutual and Thermal Diffusivities in Polystyrene Melts with Dissolved Nitrogen by Dynamic Light Scattering. Macromolecules, 54(12), 5662–5672. https://dx.doi.org/10.1021/acs.macromol.1c00819

MLA:

Piszko, Maximilian, et al. "Mutual and Thermal Diffusivities in Polystyrene Melts with Dissolved Nitrogen by Dynamic Light Scattering." Macromolecules 54.12 (2021): 5662–5672.

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