We have recently characterised a surface wetting transition for a low molecular weight oligomer in a high molecular weight rubbery polymer. Although weak surface segregation of low molecular weight compounds in polymers is known, the transition from a partial wetting layer to a thick wetting layer has received little attention. This phenomenon is of significant practical importance as it governs on the surface physical properties of hot melt adhesive formulations. In a parallel theory project, it has recently been established that the modulus of the elastomer material may also have a significant impact on the wetting behaviour, which in turn is of significant to the long term ageing and drying properties of hot melt adhesives. This beamtime proposal will directly test the new theory by measuring surface segregation in which the modulus is controlled in-situ by crosslinking.