I have characterized polymer films made of four-functional polyurethane acrylates and at the surface most of the acryloyl groups should be conversed because I've observed no corresponding peaks.
Now I wanted to find an expression for the elastic energy depending on a deformation factor. For rubbers I found the affine network model, but it predicts that the shear modulus increases with temperature what is not true for my samples. (I've measured Young's modulus with dynamic mechanical analysis). Does anyone have an idea which model could fit here?