Modes of motion in polymers

The range of motions available to a polymer spans the high-frequency secondary relaxations, involving motion of pendant groups, to the slow so-called chain modes, which reflect motion over large ( 10 nm) distances. The slowest relaxation process is the terminal mode, corresponding to motion of the entire molecule. These dynamics can be illustrated with an example, poly(vinylethylene) (PVE), an elastomer also known as 1, 2-polybutadiene. 

The pendant vinyl group in PVE undergoes a waggling motion which has minimal effect on the stress, but can be detected by dielectric spectroscopy. This 

The various motions of a polymer molecule not only occur at different rates, but they are also affected differently by temperature changes. These two aspects are considered in detail below. 

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