Processing methods stability, colorant properties

Polyacetylene n. A polymer of acetylene, made with Ziegler-Natta catalysts and usually dark-colored, with the unusual property (for a polymer) of high electrical conductivity, achieved by doping the polymer with about 1% of ionic dopant such as iodine. It may become a useful solar-cell material because its absorption spectrum closely matches the solar spectrum, but mechanical properties and stability are poor. Also, practical processing methods have yet to be developed. 

The thermal stability of PNT from different polymerization methods is presented in Table 18.7. ft appears that the colored (dark brown) but transparent PNT -N film synthesized by VDP is the cleanest film among the polynaphthalenes from other polymerization processes that have been reported. These PNT-N films from VDP also have very low dielectric constants in comparison to poly(tetra-fluoro-p-xylylene) films. PNT-N and PNT-F films have higher dissociation temperatures (>570°C) and better thermal stability (>530°C), and no film cracking was observed until PNT-F was annealed at 600°C in nitrogen. Table 18.8 presents a summary of the different properties ofPNT-N and PNT-F prepared by the VDP process. 

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