Surface segregation and blooming of crystallisable melt-processing additives

Melt processing additives are used to facilitate processing and deliver bespoke properties to polymer surfaces. At present the process by which they migrate to surfaces or interfaces is poorly understood and often inefficient. We propose to use NR to study the surface and interfacial segregation of two melt processing additives in polyethylene; one which has a melting point slightly above that of PE and the other which melts lower temperatures than PE. We wish to understand how the sequence of cooling and crystallisation may manipulate surface or interfacial segregation and particularly to resolve this on the nanometre scale with NR in the melt state. Results will complement our room temperature studies of crystalline PE with the same additives by ion beam analysis and contact angle analysis to provide a complete picture of the role of additive and matrix crystallinity in segregation.