Conducting polymers polymer-volume changes

Even when they have a partial crystallinity, conducting polymers swell and shrink, changing their volume in a reverse way during redox processes a relaxation of the polymeric structure has to occur, decreasing the crystallinity to zero percent after a new cycle. In the literature, different relaxation theories (Table 7) have been developed that include structural aspects at the molecular level magnetic or mechanical properties of the constituent materials at the macroscopic level or the depolarization currents of the materials. 

Most polymers are usually electrical insulators but need to be conductive for many engineering applications. Incorporation of conductive filler particles into the polymeric medium remains an interesting way to produce an electrically conducting polymer. Carbon materials provide electrical conduction and lead to a change in resistivity with increasing filler volume fraction in the polymer matrix. 

A feature which is common to most polymers is a change in temperature dependence of conduction as the temperature is raised through the glass transition region. Now we may expect that free volume, which affects the rate of molecular motions at the glass transition (see Section 3.3), will be equally important to the mobility of ions. Miyamoto and Shibayama (1973)... 

Figure 1 Typical stages in thermoplastics processing. (1) Solids flow (2) screw filling and solids conveying (3) melting (4) polymer melt shearing/pumping (5) shear flow in channels (6) die swell (7) elongational flow (8) volume change under pressure (9) thermal conduction and (10) shrinkage.

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