Although the surface properties and self-organisation of end-functional polymers in amorphous blends are well understood, the influence of crystallinity has received little attention. This is a vital problem to solve, since most of the commodity polymers (PE, PET, PP) whose surface properties we wish to control with functional polymer addtives are semi-crystalline. The bulky functional group of an end-functionalized polymer may partially or completely exlude these molecules from the crystalline domains in a semi-crystalline polymer. It is known that crystallinity can enhance surface segregation, therefore potentially amplify the effect of the surface-active functional polymer. We seek beamtime on IRIS or OSIRIS to explore the distribution of a functionalized polymer between crystalline and amorphous domains in a model semicrystalline polymer blend.