Acetylene copolymers with phenylacetylene

Interesting evidence supporting the mechanism of polymerisation of acetylenes via carbene species is provided by the block and random copolymerisation of acetylenic monomers with cycloolefins. For instance, block copolymers of acetylene and cyclopentene with the WC —AlEtCT catalyst [41] and block copolymers of acetylene and norbornene with the (MeA. Oj2W(=NAr)= CHMe3 catalyst [42] have been obtained moreover, random copolymers of phenylacetylene and norbornene with the WC16 catalyst have also been obtained [149, 150],... 

Fig. lO.S UV/visible absorption spectra of statistical copolymers of phenylacetylene with acetylene, containing from zero to 81.7 mol% acetylene units in going from spectrum 1 to spectrum 9. Solvent, CH2CI2. The absorption maximum at 508 nm corresponds to an average of 9-10 conjugated double bonds (Kanischka 1988). 

Acetylene and disubstituted acetylene (such as 2-butyne) do not form copolymers with SO2. However, -alkyl acetylenes and phenylacetylene reaction to give a copolymer. 

As discussed earlier, substitution onto the polyacetylene chain invariably has a deleterious effect on dopability and conduction properties. At the same time the stability tends to improve. Masuda et al.583) studied a large range of substituted polyacetylenes and found that stability increased with the number and bulkiness of the substituents, so that the polymers of aromatic disubstituted acetylenes were very stable, showing no reaction with air after 20 h at 160 °C. Unfortunately, none of these polymers is conducting. Deitz et al.584) studied copolymers of acetylene and phenylacetylene they found that poly(phenylacetylene) degrades even more rapidly than does polyacetylene and that the behaviour of copolymers is intermediate. Encapsulation of the iodine-doped polymers had little effect on the degradation, which is presumably at least in part due to iodination of the chain. 

A copolymer of acetylene and phenylacetylene containing up to 20% acetylene was obtained [102]. Conductivity decreased with increasing phenylacetylene content. 

High-molecular-weight copolymers were obtained from 1-phenyl-1-propyne and monosubstituted acetylenes by coordination polymerization with tungsten /Lt-hydride complexes as catalysts in toluene as a solvent [122]. The coefficients of permeability of Nj and O2 through the membranes obtained from phenylacetylene/1-phenyl-1-propyne copolymers were evaluated. 

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