Dewetting of glassy polymer films

Dynamics and morphology of hole growth in a film of power hardening viscoplastic solid [yield stress similar to(strain-rate )(n) ] is investigated. At short times the growth is exponential and depends on the initial hole size. At long times, for n>1/3, the growth is again exponential but with a different exponent. However, for n<1/3 the hole growth slows and the hole radius approaches an asymptotic value at long times. The rim shape is highly asymmetric, the height of which has a power law dependence on the hole radius (exponent close to unity for 0.25<n<0.4 ). The above results explain recent intriguing experiments of Reiter [Phys. Rev. Lett., 87, 186 101 (2001)] on dewetting.