Dependence of the in-plane modulus of thin free-standing polymer films

We employ an axi-symetric deformation and modulus test to measure the in-plane elastic modulus of free-standing polymer films. This method measures the deformation of a thin spincast film when a flat circular punch is brought into contact with the sample. The use of a small, flat punch minimises uncertainties in the experiment, while the use of spincast films provides a very smooth surface. We will present a study of the dependence of the elastic modulus on the film thickness and the annealing history of the samples.