Comprehensive investigation of the viscoelastic properties of PMMA by nanoindentation

• Published in: Polymer testing Vol. 93; p. 106978
• Main Authors: Christöfl, Petra, Czibula, Caterina, Berer, Michael, Oreski, Gernot, Teichert, Christian, Pinter, Gerald
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01-01-2021; Elsevier
• Subjects: AFM; Amorphous; Compression test; Creep; Nanoindentation; AFM; Amorphous; Creep; Compression test; Nanoindentation
• ISSN: 0142-9418
• DOI: 10.1016/j.polymertesting.2020.106978

Instrumented nanoindentation (NI) was used to examine the viscoelastic properties of poly(methyl methacrylate) (PMMA) as an amorphous polymer model. An evaluation combining adhesive contact and empiric spring–dashpot models has been applied to obtain the instantaneous elastic modulus E0 and the infinitely elastic modulus E∞ from nanoindentation creep curves. The value of E0 has been compared to moduli obtained with atomic force microscopy-based nanoindentation (AFM-NI) and compression tests. Furthermore, the elastic modulus has been evaluated by the method introduced by Oliver and Pharr (O&P) for the NI and AFM-NI results. Comparison of the elastic modulus E0 from the creep measurements of NI and AFM-NI to compression tests reveals good agreement of the results. However, only the O&P based AFM-NI results yield to lower values.
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•Viscoelastic properties of PMMA were gained by nanoindentation evaluated with adhesive contact and spring-dashpot models.•Comparison with atomic force microscopy nanoindentation and compression tests reveals good agreement with the results.•Different moduli values of O&P based AFM-NI may be related to the shallow indentation depth of AFM-NI in contrast to NI.