Much attention has been paid to cross-linked polyolefin in order to use them as membranes and/or barrier systems for chemical compounds or simply to alter the properties of the material made of polyolefin. For the specific application of polymeric materials not only their chemical composition and network structure are important but also their surface roughness and / or coating. Therefore it is of importance to combine different analytic techniques in order to characterize the material in detail which also results in a better understanding of the expected performance of such material. Here, a broad spectrum of methods will be provided to visualize and measure the different properties between non-cross-linked and cross-linked polymers. The methods include pyrolysis gas chromatography coupled with mass spectroscopy, Rheology, microscopy and gravimetric analysis. The difference in the degree of permeability shall also be investigated using a chosen solvent.