Annealing of Polymer Membranes

Annealing can be defined as a process where a material undergoes a heat treatment to a certain temperature, is kept there for a definite time, and is then cooled to room temperature in order to alter the material properties. The annealing process is time and temperature dependent.

Annealing of polymers is a heating of a polymeric part to below its glass transition temperature in order to relieve the internal stresses introduced during its fabrication (molding, cooling after molding, machining, welding, etc.).

Annealing of conjugated polymers and polymer blend films is a widely used process that achieves optimal film morphology and therefore improves material properties, such as electrical mobility for photovoltaic devices and other applications. Annealing of ion-conducting polymers reduces the excessive swelling observed in presence of water.

In particular, annealing is used (Young and Lovell 1991):

• (a) To increase the melting point of some polymers because it facilitates the melting...