Studies of relaxation phenomena in polymers. IV. Superimposed transition mechanisms in polymethacrylates

The existence of superimposed transition mechanisms in the “ T g region” of polymethacrylates has been indicated by several authors including Ferry and co‐workers, who also have tried to separate the mechanisms. Using the general properties of the viscoelastic function log J 2 = g α {log J 1 } and a simple weighting model, the α‐and β‐mechanisms have been separated. The viscoelastic function log J 2 = g β{log J 1 } is determined and is found to coincide both where different polymethacrylates are concerned and for the calculated as well as the directly measured data.