Temperature-dependent soft wetting on amorphous, uncrosslinked polymer surfaces.

The wetting of polymer melts at high temperatures is studied by placing a glycerol drop on a poly( n -butyl methacrylate) film and measuring the wetting ridge. The height of the wetting ridge grows continuously over time. These wetting ridge growth rates can be explained by polymer chain dynamics occurring at the molecular level, determined using oscillatory shear rheology of the polymer melt. The shape of wetting ridge profile can be modeled using an equation previously used for elastomers, with a simple modification that incorporates the time-dependent storage modulus of the uncrosslinked melts.