2020 Volume 71 Issue 3 Pages 249-254
Because polymer materials are used widely as film materials, measuring the viscoelastic properties of local areas of polymer materials is important. Viscoelasticity measurements have been conducted conventionally using dynamic mechanical analysis（DMA）. However, DMA is applied mainly to bulk-state polymers. It is unsuitable for measuring the local areas of polymers. Nanoindentation can measure the mechanical properties of very small surface areas of materials. Used with a vibrating indenter, it can also measure the viscoelastic properties of organic materials. As described herein, the PMMA and PVC viscoelasticity were measured at various temperatures using dynamic nanoindentation. PMMA and PVC are standard materials for measuring viscoelasticity of polymers certified by AIST using DMA. The storage/loss moduli were obtained by dynamic nanoindentation using a Berkovich-type indenter. Those results were compared with the certified values. The dynamic viscoelastic properties obtained by dynamic nanoindentation showed a similar temperature-dependence trend to that of certified values obtained using DMA. Dynamic nanoindentation using a Berkovich-type indenter is useful to measure the viscoelastic properties of polymers, although the suitable testing specifications should be investigated later.
