Advances in Contact Dynamic Mechanical Analysis of Rubber Compounds – Applications, Methodologies, and Sample Preparation

Nanoindentation is a powerful technique for characterizing small volumes of material for the mechanical properties of elastic modulus, hardness, and viscoelasticity. The primary advantage of this technique for polymers is the ability to resolve these properties with spatial resolutions on the micro- and nano-scales. In this presentation, details of the contact dynamic mechanical analysis (CDMA) technique using a nanoindenter platform will be covered. A comparison of these results to traditional dynamic mechanical analysis (DMA) results will be made. The primary advantages of the CDMA technique - which include the ability to evaluate gradients in rubber compounds and the ability to map material degradation zones - will be shown. In addition, the presentation will cover sample preparation methods. The combination of sample preparation methods and the CDMA technique allows tire samples to be tested in cross-section without the difficulty of dissecting the individual polymer layers. CDMA provides a new measurement technique for obtaining viscoelastic properties on volumes of material previously considered too small for characterization through the dissection technique.