a) b - École Polytechnique de Montréal

Posthuma de Boer, 1999) (Kumin & Chang Dae, 1996). Linear time dependence was observed in
the coarsening of immiscible co-continuous blends as shown by experimental pore size growth at
a constant temperature of 200°C in Figure 2-15. Sarazin et al.(Sarazin & Favis, 2003; Sarazin,
Roy, & Favis, 2004) showed that for a binary blend of PLLA and two typical polymers, domain
growth is more rapid at a higher temperature over a longer time.
.
a) b)
c) d)
Figure 2-14. Coarsening process in co-continuous structure upon annealing.(a) the thin rod
merges/flows into thick ones at both sides, the thick rod merges into a much thicker one at the
same time; (b) the thin rod becomes thinner during the merging process; (c) the thin rod
breaks/splits; and (d) the residual parts retract/shrink to the thick rods.(Yuan, 2005)
Veenstra et al.(Harm Veenstra, Van Dam, & Posthuma de Boer, 2000) described a relationship
between coarsening and the fiber retraction process. They showed the evolution of a polymer rod
to a sphere in a polymer matrix during the annealing process. However, this mechanism is unable
to explain some facts about coarsening and is not in agreement with experimental data(Zhenhua
Yuan, 2005).
Reignier et al.(Reignier & Favis, 2000) investigated static coalescence for a composite droplet
morphology in a ternary blend. A similar mechanism governed by the same methodology for
coalescence of each phase in binary blend and ternary blend was found. They set the temperature
at 200°C and observed that core-core and shell-shell coalescence occurred from 2 min to 90 min.
They reported that the only difference is that the ternary blend showed a dual coalescence
process, first between subinclusions within composite droplets and second between composite
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