Sh. Anastasiadis et Sg. Hatzikiriakos, THE WORK OF ADHESION OF POLYMER WALL INTERFACES AND ITS ASSOCIATION WITH THE ONSET OF WALL SLIP/, Journal of rheology, 42(4), 1998, pp. 795-812
The interfacial characteristics of a variety of polymer/wall interface
s were measured by using the sessile drop method in order to calculate
the work of adhesion. Polymers included linear low-density as well hi
gh-density polyethylenes, while wall substrates included clean stainle
ss steel and modified stainless steel by applying two different fluoro
polymers in order to alter its surface energy. A linear correlation is
found between the critical shear stress for the onset of slip and the
work of adhesion of the corresponding polymer/wall interface, in agre
ement with earlier publications of Hill et al. (1991) and Hatzikiriako
s et al. (1993). In the present work, the experimental results are int
erpreted in terms of parameters defined by these two theories. It is s
uggested that small deviations from the no-slip boundary condition in
the case of polymer melt flow are due to a stress-induced chain detach
ment/desorption of polymer chains from the wall. (C) 1998 The Society
of Rheology.