Polypyrrole chain alignment

Figure 15.6 Polypyrrole chain microstructure before and after processing using stretching or rolling leading to chain alignment in the machine direction (MD). (Reprinted with permission from Polymer, Anisotropic actuation of mechanically textured polypyrrole films by R. Z. Pytel, E. L. Thomas, Y. Chen, and I. W. Hunter, Polymer, 49, 5, 1338-1349. Copyright (2008)...

Oriented thin films can be also obtained by stretching of poly acetylene, poly(alkyl)thiophene and some polydiacetylene isotropic thin films. In this case polymer chains align in the stretching direction. Some films like poly tiophene, polypyrrole can be obtained by electrochemical deposition. 

The chemical structure of the counterion may have a profound influence on the morphology and conductivity of the polymer. For instance, polypyrrole made in the presence of dodecyl sulfate is very smooth, dense, stable, and highly conducting, whereas polypyrrole made in the presence of perchlorate ion has a cauliflower morphology and its conductivity is about 100 times lower than with dodecyl sulfate. Apparently long-chain anions have a kind of aligning effect on the polymer chains. Also, anions and other... 

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