Neutron reflectivity investigations of semi-crystalline polymer interfaces

Neutron reflectivity measurements have been made on immiscible amorphous-crystalline and crystalline crystalline polymer interfaces in the melt. Using a special reflectivity cell the macroscopic roughness and waviness associated with the crystalline polymer can be removed. From the measurement of the interfacial width between the two polymers the Flory-Huggins interaction parameter, χ, and interfacial tension, γ₀, have been extracted. The measured interfacial width has to be deconvoluted into the real and capillary wave component contributions to interfacial broadening. Interaction parameters and interfacial tension values for both dPS-PE and dPP-PE systems have been evaluated,