Determining the viscoelastic parameters of thin elastomer based materials using continuous microindentation

作者：Kohl James G^*; Singer Irwin L; Simonson Duane L

来源：Polymer Testing, 2008, 27(6): 679-682.

DOI：10.1016/j.polymertesting.2008.04.010

• silicone coating
• viscoelasticity
• modulus
• indentation

Depth-sensing indentation (DSI) was used to evaluate the viscoelastic properties of three proprietary silicone-based coatings and four butyl-based rubber sheets. The coatings are used as layers in silicone bilayer coatings. The elastic indentation modulus, E* irrecoverable deformation energy and elastic energy were determined in an earlier study using the unloading data of DSI tests and applying a creep correction method proposed by Ngan et al. The model used in this study to characterize the coatings was the standard four parameter Maxwell-Voigt viscoelastic model combined with the elastic indentation load-depth model for a Berkovich indenter as proposed by Fischer-Cripps. This model fits the data quite well, The parameters E-1*, E-2*, eta(1), and eta(2) were found by curve fitting this model with the indentation depth versus time data while held at a constant maximum load. The parameter E-1* is equivalent to E*; values of El obtained using the Fischer-Cripps technique were 6.8 +/- 0.9 MPa, 109 +/- 7 MPa, and 4.2 +/- 0.5 MPa for bond coat A, bond coat B, and the top coat, respectively. One purpose of this paper is to demonstrate a technique to determine viscoelastic parameters of silicone-based elastomers. It is hoped that these parameters may then be used in the evaluation and development of more durable silicone-based foul release coatings. Another purpose is to apply this technique to other elastomer-based materials such as butyl-based rubbers.

• 出版日期2008-9