Polymers quasi-inorganic

DiolOCtriC Thoory. The piezoelectricity in amorphous polymers differs from that in semicrystalline polymers and inorganic crystals in that the polarization is not in a state of thermal equilibrium, but rather a quasi-stable state because of the freezing-in of molecular dipoles. The result is a piezoelectric-hke effect. A theoretical model for polymers that have frozen-in dipolar orientation was presented to explain piezoelectricity and p5Toelectricity in amorphous polymers such as poly(vinyl chloride) (39). 

These include inorganic and quasi-inorganic polymers, double-strand (ladder) polymers, siloxanes and silicones, and oligomers and telomers. A comprehensive review of structure-based and source-based representations for these types of polymers has been published (40). 

Inorganic and Quasi-inorganic Polymers. A polymer need not be completely inorganic to be classified as an inorganic polymer an inorganic backbone is sufficient, even if there are organic moieties attached to a backbone atom. 

The piezoelectricity in amorphous polymers differs from that in semi-crystalline polymers and inorganic crystals in that the polarization is not in a state of thermal equilibrium, but rather a quasi-stable state due to the ffeezing-in of molecular dipoles. As mentioned by Broadhurst and Davis (55), four criteria are essential to make an amorphous polymer exhibit piezoelectric behavior. First, molecular dipoles must be present. As seen in Table 1, these dipoles are typically pendant to the polymer backbone as are the nitrile groups in PAN, PVDCN-VAC, and (p-CN) APB/ODPA. However, the dipoles may also reside within the main chain of the polymer such as the anhydride units in the (P-CN) APB/ODPA polyimide. In addition to a dipole moment X, the dipole concentration N (number of dipoles per unit volume) is also important in determining the ultimate polarization, P , of a polymer. 

Overall, the polymer of tomorrow will reach into inorganic, quasi metallic combinations on one side, and bio polymers of living tissue on the other. These will provide the widest interface in the science and the technology of matter. Both the wonderful spiral conformation of collagen, Fig. 23, and the subtle information content of its peptide components in muscle action are qualities to be sought in polymers made by people. 

Nomenclature for regular single-strand and quasi-single-strand inorganic and coordination polymers (Provisional), Pwre Chem. 53, 2283-2302 (1981). Superseded by Ref 17. 

IUPAC, Nomenclature for Regular Single-Strand and Quasi-Single-Strand Inorganic and Coordination Polymers ,... 

A Macromolecular Division of IUPAC was created in 1967, and it created a permanent Commission on Macromolecular Nomenclature, parallel to the other nomenclature commissions. The Commission over the years has issued recommendations on basic definitions, stereochemical definitions and notations, structure-based nomenclature for regular singlestrand organic polymers and regular single-strand and quasi-singlc-strand inorganic and coordination polymers, source-based nomenclature for polymers and abbreviations for polymers. All of these are collected in a compendium referred to as the IUPAC Purple Book. 

During the past decade there has been very intense experimental and theoretical research on the physics and chemistry of polymeric materials. This work has led to the discovery of a great number of organic and inorganic crystals built from polymers or molecular stacks which have a quasi-one-dimensional electronic system and exhibit fascinating electric, magnetic, etc. properties. Other polymers have proved to play a fundamental role in the biosciences. 

Nomenclature for Regular Single-strand and Quasi Single-strand Inorganic and Coordination Polymers, L.G. Donaruma, B.P. Block, K.L. Loening, N. Plate, T. Tsuruta,... 

Some quasi-one-dimensional conductors ( KCP and the quinolinium and acridizinium TCNQ salts) display an intrinsic disorder. Apparently such a disorder does not result in a short free path, since in all given compounds there is a dielectric transition (6). The electron scattering on the impurities seems to explain the absence of the dielectric transition in the quasi-one-dimensional inorganic polymer (SN)X. 

Contrary to inorganic crystalline semiconductors, where charge is transported in general by electrons in the conduction band and holes in the valence band, in doped conjugated polymers charged solitons, polarons, and bipolarons act as charge carriers. These quasi-particles are the direct consequence of the strong electron-phonon interaction present in these quasi-one-dimensional polymers. 

International Union of Pure and Applied Chemistry, Nomenclature of Regular Double-Stiand and Quasi-Single-Stiand Inorganic and Coordination Polymers (Recommendations 19S4), Pure Appl. Chem., 57, 149-168 (1985). 

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