Evaluation of methods to accurately characterize the thermal conductivity of micro-and nanocellular polymers based on poly(methyl-methacrylate) (PMMA) produced at lab-scale

• Published in: Polymer testing Vol. 117; p. 107842
• Main Authors: Sánchez-Calderón, Ismael, Sillero, Ángel, Lizalde-Arroyo, Félix, Bernardo, Victoria, Martín-de-León, Judith, Rodríguez-Pérez, Miguel Ángel
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01-01-2023; Elsevier
• Subjects: Nanocellular polymers; Steady-state; Thermal conductivity; Transient; Nanocellular polymers; Thermal conductivity; Steady-state; Transient
• ISSN: 0142-9418; 1873-2348
• DOI: 10.1016/j.polymertesting.2022.107842

The characterization of the thermal conductivity of new and enhanced thermal insulators developed at lab-scale is a challenge. The small dimensions of the prototypes make impossible the use of the conventional techniques because steady-state methods require large samples. Furthermore, the accuracy of transient methods to measure the thermal conductivity is not clear. In this work, we compare four different approaches to measure the thermal conductivity of small prototypes of nanocellular poly(methyl-methacrylate) (PMMA). Both steady-state and transient techniques are used. Results show that the transient plane source method is not suitable for the characterization of these materials (the deviation from the steady-state methods is on average higher than 15%). In addition, two different approaches for measuring the thermal conductivity of small samples via a steady-state technique are proposed and validated.
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•Comparison of different routes to characterize small insulating prototypes.•The transient plane source (TPS) method is not suitable for the characterization.•Two steady-state-based approaches are proposed and validated.