Macro-, micro- and nanomechanical characterization of crosslinked polymers with very broad range of mechanical properties

0536180 - ÚMCH 2021 RIV CH eng J - Journal Article
Šlouf, Miroslav - Strachota, Beata - Strachota, Adam - Gajdošová, Veronika - Bertschova, V. - Nohava, J.
Macro-, micro- and nanomechanical characterization of crosslinked polymers with very broad range of mechanical properties.
Polymers. Roč. 12, č. 12 (2020), s. 1-26, č. článku 2951. E-ISSN 2073-4360
R&D Projects: GA TA ČR(CZ) TN01000008; GA ČR(CZ) GA19-04925S
Institutional support: RVO:61389013
Keywords : microindentation * nanoindentation * depth-sensing indentation
OECD category: Polymer science
Impact factor: 4.329, year: 2020
Method of publishing: Open access
https://www.mdpi.com/2073-4360/12/12/2951

This work is focused on the comparison of macro-, micro- and nanomechanical properties of a series of eleven highly homogeneous and chemically very similar polymer networks, consisting of diglycidyl ether of bisphenol A cured with diamine terminated polypropylene oxide. The main objective was to correlate the mechanical properties at multiple length scales, while using very well-defined polymeric materials. By means of synthesis parameters, the glass transition temperature (Tg) of the polymer networks was deliberately varied in a broad range and, as a result, the samples changed their mechanical behavior from very hard and stiff (elastic moduli 4 GPa), through semi-hard and ductile, to very soft and elastic (elastic moduli 0.006 GPa). The mechanical properties were characterized in macroscale (dynamic mechanical analysis, DMA), microscale (quasi-static microindentation hardness testing, MHI) and nanoscale (quasi-static and dynamic nanoindentation hardness testing, NHI). The stiffness-related properties (i.e., storage moduli, indentation moduli and indentation hardness at all length scales) showed strong and statistically significant mutual correlations (all Pearson′s correlation coefficients r > 0.9 and corresponding p-values < 0.001). Moreover, the relations among the stiffness-related properties were approximately linear, in agreement with the theoretical prediction. The viscosity-related properties (i.e., loss moduli, damping factors, indentation creep and elastic work of indentation at all length scales) reflected the stiff-ductile-elastic transitions. The fact that the macro-, micro- and nanomechanical properties exhibited the same trends and similar values indicated that not only dynamic, but also quasi-static indentation can be employed as an alternative to well-established DMA characterization of polymer networks.
Permanent Link: http://hdl.handle.net/11104/0314413