A numerical study of interdiffusion processes at polymer-polymer interfaces
Sprache des Titels:
Englisch
Original Buchtitel:
AIP Conference Proceedings
Original Kurzfassung:
Numerous plastic products are manufactured using processing techniques that enable the combination of
different polymeric materials within multilayer structures (e.g., co-extrusion, co-injection molding, and extrusion
lamination) to obtain tailored properties. Providing sufficient adhesion between the individual layers is of major
importance. For a wide range of polymeric material combinations, interdiffusion of the macromolecules is the mechanism
that mainly determines adhesion. Understanding the interdiffusion process and predicting concentration profiles and thus
the resulting interphase thickness under given processing conditions (e.g., contact time, interfacial temperature) contributes
to efficient manufacturing processes yielding multilayer plastic products that are optimized for sophisticated applications.
In this work, we investigated the formation of an interdiffusion layer (interphase) between two polymer melts under static
conditions by analyzing the concentration profiles developing across the interphase and the resulting mutual
interpenetration depth. The interdiffusion process is modeled based on Fick?s diffusion theory using concentration-
dependent interdiffusion coefficients. The compatibility between different polymer melt is considered by applying the
interaction theory according to Flory and Huggins. Further, all independent influencing parameters that govern the
interdiffusion process are identified by transforming the diffusion equation into dimensionless representation. By varying
these characteristic dimensionless parameters within particular ranges and numerically solving the partial differential
equations, we analyzed their influence on the formation of the interphase and the final interdiffusion layer thickness.