Naarmann-Type Polyacetylene

For polymerization, the catalyst is brought onto a substrate as a thin layer and acetylene is blown over the catalyst at room temperature in contrast to Shirakawa synthesis, were the reaction takes place at -78 C. As a result, rather homogeneous polyacetylene films are obtained, whose thickness can be controlled by the thickness of the layer of catalyst. 

The undoped samples exhibit lower defect concentrations than conventional polyacetylene. Crystallinity is about 80 % and the density is 0.9 g/cm /15, 16, 18/. SEM pictures of strech-aligned samples show a fibrillar morphology with a partial orientation parallel to the stretching direction and typical fibrillar diameters of 50 - 100 nm /40/ (see chapter 6).  

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A study on polyacetylene of the Naarmann-Theo-philou type [14] has been published by Djurado et al. [82], using both x-ray and neutron diffraction. This type of polyacetylene is characterized by a high value of the longitudinal coherence length, Z. n = 170 A, and a reduced rate of isomerization at 300 K compared to... 

Theophilou, N., and Naarmann, H., Influence of the catalyst system on the morphology, structure and conductivity of a new type of polyacetylene, Makromol. Chem. Macromol. Symp., 24, 115-128 (1989). 

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