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Diacetylenes description

The solid state polymerisation of diacetylenes (2) with U.V. radiation, heating or shear force is most indicative of the predominant influence of electron-lattice coupling. The details of the chemical changes that occur during th polymerisation process are crucial (2,40) but the overall description only needs part of this chemical information. The kinetics and thermodynamics of the polymerisation process using an elastic strain approach have been worked out in (41). [Pg.181]

Although interesting within the framework of polymer physics and material science this would not be sufficient to attract so many workers from areas outside of conventional polymer research. Additional interest arouse because of the unusual structure of the polymers obtained via solid-state polymerization of diacetylenes and because of the mechanistic features related to its formation. Polydiacetylenes exhibit a fully conjugated and planar backbone in the crystalline state and are thus considered the prototype study object as far as the nature and physical behavior of polyconjugated macromolecules are concerned Theoretical discussions of the electronic structure of these polymers (2) lead to a description in terms of a wide band one-dimensional semiconductor... [Pg.154]

This essentially correct description went unnoticed apparently these insights were ahead of their time. Part of the lack of interest may have been due to the fact that the dihalogen-diacetylene crystals exploded under impact. In any event, it was a further 39 years before the important x-ray studies were undertaken. [Pg.129]

For systems of rigid poly diacetylenes with functional or ionic side groups and car-boxylated or sulfonated polystyrene or sulfonated polyester-urea urethanes, molecular composites could be achieved by ionic interactions [51]. The blends exhibited no microphase separation and the miscibility on a molecular length scale was proven by infrared spectroscopic, dynamic mechanical and differential scanning calorimetry analysis. The molecular reinforcement amounted to up to 1 order of magnitude in compliance with a Halpin Tsai description and was achieved by only a few weight percent of the rigid compound. [Pg.284]

What is the cr-n orbital description of diacetylene, propylene, and allene ... [Pg.190]


See other pages where Diacetylenes description is mentioned: [Pg.510]    [Pg.13]    [Pg.377]    [Pg.34]    [Pg.73]    [Pg.377]    [Pg.515]   
See also in sourсe #XX -- [ Pg.218 ]




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Diacetylenes

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