Polydiacetylenes molecular weight

Another important step was made by Wegner who obtained crystalline polydiacetylenes of high molecular weight exhibiting a fully conjugated backbone [113]. The theory describes the electron structure of the polydiacetylenes in the frame of the ID wideband semiconductor. The polydiacetylene systems are... 

Determining the length of the polymer product is of key importance for understanding the polymerization process and received considerable attention ever since the reaction was discovered. On the experimental side direct determination is impeded by the insolubility of most polydiacetylenes — exceptions will be mentioned below — which precludes application of standard methods for measuring the molecular weight. 

A deeper insight into the reaction mechanism may elucidate the conversion dependence of the molecular weight and its distribution. Owing to the extreme insolubility of the better investigated polydiacetylenes like PTS, however, only very limited experimental data have been available until recently from indirect determinations, e.g. from mechanical properties or diffuse scattering of partially polymerized crystals. 

Since Patel discovered in 1978 that poly3BCMU (R = R = —(CH2)3—OCONH— CH2—COO—(CH2)3CH3, cf. Table 1) is a readily soluble polymer the study of the solution properties of polydiacetylenes attracted increasing interest 66.i< -u5) with such samples the molecular weight and its distribution can be determined using standard techniques and related to the conversion and other experimental parameters. This analysis has been carried out in great detail for PTS-12... 

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