Relaxation of residual stress and reentanglement of polymers in spin-coated films.
Performing detailed studies of viscoelastic dewetting of thin polystyrene films on solid substrates, we demonstrate the existence of residual stress due to strongly out of equilibrium chain conformations and a reduced entanglement density resulting from film preparation by spin coating. The ratio of stress over elastic modulus was found to increase strongly with decreasing film thickness and increasing chain length. Full equilibration of chain conformations required long times comparable to bulk reptation times. However, for chains longer than about 3000 monomers, the residual stress relaxed faster, at a rate independent of chain length.
Laboratoire de Physicochimie des Polymères, Centre d'Innovation et de Recherche en Matériaux Polymères, Université de Mons Hainaut, 20, Place du Parc, B-7000 Mons, Belgium. pascal.damman@umh.ac.be
Pascal
P
Damman
Sylvain
S
Gabriele
Séverine
S
Coppée
Sylvain
S
Desprez
Didier
D
Villers
Thomas
T
Vilmin
Elie
E
Raphaël
Moustafa
M
Hamieh
Samer Al
SA
Akhrass
Günter
G
Reiter