Indentation testing of polystyrene through the glass transition

The determination of the thermomechanical properties of polymers is vitally important in their characterization. Indentation methods are especially attractive for polymer coatings, since the coatings do not need to be removed from the substrate. In this study, bulk polystyrene has been analysed by conventional cantilever testing and by spherical indentation at different temperatures. It was found that reasonable estimates of the glassy modulus, rubbery modulus and glass transition temperature could be obtained from simple load/unload indentation.