Interface-induced coarsening process in polymer blends

The coarsening process of the droplets in a two-phase polymer blend (PP/EVA c) was studied under two-dimensional and three-dimensional conditions using a phase contrast microscope and computer image analyzer. The results showe d that under three-dimensional conditions the growth of the droplet's radiu s with time follows r(3) similar to t(1.01), corresponding to the evaporati on-condensation theory of Lifshitz-Slyozov, r(3) similar to t, while under two-dimensional conditions the growth law is r(3) similar to t(1.31). The g rowth rate of the droplets under two-dimensional conditions is faster than that under three-dimensional conditions. This difference is caused by an in terfacial interaction (wetting effects) between the substrates and polymer blend. The existence of the interface promoted the coarsening process of th e polymer blend under two-dimensional conditions. (C) 2001 Academic Press.