The transition associated to the highest temperature, relaxation
(at 472 K), is assigned to glass transition of the main chains of
the polymer.
The identification of the other relaxations is more difficult and
contradictory due to the number of smaller structural units which
can associate to these relaxations. These situations are more complicated
with plasticization or chemical modification of CA.
The relaxation * (at 323–373 K) is associated to hydrated CA
and it is related to the loss of water associated with different groups
or the interaction of single repeat units (Yarsley, Adamson, Flavell,
& Perkins, 1964). The peak is very weak and its identification is
difficult.