Head groups, tethered chains

If, however, the hydrophobic polymer is investigated above its glass transition, the polymer chains can rearrange, flow and fuse to form a continuous film. In the case of non-glassy non-surface active chains without a hydrophilic head group, the polymer will not form a thin continuous layer, but retract into small droplets. If, however, a polar head group is attached to these polymer chains, the polymer is tethered to the interface via these head groups and forms a melt brush . 

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