INTERFACIAL STRUCTURE FOR A COMPATIBLE POLYMER BLEND FOR SHORT AND INTERMEDIATE ANNEALING TIMES

The neutron specular reflection technique has been used to study the nature of the interface between solution-chlorinated polyethylene (SCPE) and deuterated poly(methyl methacrylate) (dPMMA) as the sample is annealed at 120-degrees-C for short and intermediate times. At this temperature the system is in the two-phase region of the phase diagram. The shape of the polymer/polymer interface is very asymmetrical, being rather sharp on the dPMMA side and presenting a long tail towards the SCPE side. The position of the interface shifts with time towards the dPMMA, and the magnitude of the shift depends linearly on the square root of the annealing time. Three regimes are observed in the interfacial movement. The shape of the interface and the magnitude of the interfacial shift are analysed in terms of current diffusion theories.