losses in the underlying polymer et al. state that

In Fig. 6 we have shown two different regimes that both show an increase in adhesion with contact time. We conclude that this is the result of inter-penetration of the surface layers for reasons which are discussed later. In this case we cannot determine any separation rate dependence as, if there is any, it is overwhelmed by the inter-penetration effects. Thus the large increase in the adhesion is related to the increase in the effective contact area between the two surfaces as the polymer chains interpenetrate into the opposing polymer matrix (and are not related to the separation rate).