ESR Spectra of Pristine and AsFs Doped Polyacetylene PA

As shown in Fig. 7.47 the asymmetry increases with the amount of AsFs uptake. The doping should result in free carriers with an associated increase in the spin 

An example of an ESR spectrum of AsFs doped PA is also shown in Fig. 7.48. The excellent agreement between the experimental and calculated spectra indicates that the line shape is Dysonian. The highest doping levels result in a skin depth less than the sample thickness. For a 10 S/cm, the skin depth was calculated 

We can relate structure and molecular motion of polymer chain to chemical reaction in solid polymers by the ESR method. In this chapter, we present ESR studies that are particularly effective in three areas of polymer science. 

Finally, we present an example of the relation between structure, molecular motion and chemical reaction in solid polymers studied by the ESR method as one of the conclusions in this chapter. 

The conclusion reached is that chemical reactions are closely related to molecular motion and structures, where molecular conformation and molecular orientation are important parameters. We have discussed whether the hydrogen abstraction reaction of peroxy radicals in the inner crystalline region of polypropylene is due to then-abstraction of the hydrogen from the intra-chain segment or inter-chain one. (1) It was confirmed that the unstable and mobile radicals participated in a rotation or a rotatory vibration of the COO group around the main chain axis. (2) The conformational structure of the mobile peroxy radicals was close to a skew conformation. (3) It could be safely concluded that the mobile peroxy radicals were trapped in disordered sites in the inner crystalline region. 

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