Young's modulus and loss tangent measurement of polydimethylsiloxane using an optical lever

In this article, the Young's modulus and the loss tangent of polydimethylsiloxane (PDMS) is obtained in the frequency range between 10 and 1500 Hz using an optical technique. The first three mechanical modes of vibrating PDMS beams are detected by measuring the tip rotational displacement using an optical lever. The experiments are carried out for 10:1 and 20:1 volume mixing ratios between the polymer base and the curing agent. The experimental results show that the Young's modulus varies between 1 and 2.6 MPa for 10:1 while its values are between 0.6 and 1.1 MPa for 20:1. The loss tangent is between 0.2 and 0.4 for 10:1 and 0.2 and 0.5 for 20:1. However, the measured values of the loss tangent are greater than the values reported in ref. 13. We also found that if the PDMS is not cured properly, its mechanical properties are time dependent. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2016, 54, 747–751