Chains and Polymers

Conducting polymers with -phenylene groups in the backbone are generated by metathesis (Equation 7). Doping of these polymers with acceptors such as I2, Br2 or AsFs increases the conductivity. Similar polymers have been prepared from 1,3- and 1,4-ClSC6H4SCl.  

---

Other polyamides produced experimentally include polymers with active lateral groups (hydroxy, keto groups etc.), polymers with heteroatoms (sulphur and oxygen) in the polyamide-forming intermediates, polymers with tertiary amino groups in the main chain and polymers with unsaturation in the main chain. There does not, however, appear to have been any serious attempt to develop unsaturated polyamide analogues to the polyester laminating resins. 

For infinitely long chains (polymers), terms (Gcx Gex) + (Gdefi Gdefl) will be close to zero. Consequently, in infinitely long chains and polymers, free energy change in the process can be close to the one in similar reactions of low-molecular compounds (P. Flori principle) [10]. 

If a mixture is made of individual polymer chains and polymer clusters, the measurement of static LLS will lead to an apparent weight-average molar mass Mw>app which is expressed by... 

Although main chain chirality refers to both polymers with stereogenic centers in the main chain and polymers with main chains consisting of helical stereogenic bonds induced by chiral side groups this work mainly focuses on polysilanes exhibiting this latter type of chirality. 

Derivatives with silicon-silicon bonds include cycles, chains and polymers. The relationships between derivatives that contain two or more contiguous silicon centers is shown in Scheme 5. In most cases the origin of the catenated derivatives may be traced back to a dihalosilane. 

Since chemisorbed ethylene disappears by initiation reaction with adsorbed hydrogen, pro-pagation reaction with surface-bound polymer chain, and polymer chain transfer with monomer (Fig. 9.8), one may write (Friedlander and Oita, 1957) ... 

Group A, polymers with cis/trans double bonds, vinyl polymers with side groups/chains and polymers with p-phenyl groups. 

In the literature, various reasons for formation of polymers with broad MMD on heterogeneous ZN catalysts are discussed. Convincing evidence has been obtained using the SF method that the reasrni is heterogeneity of the active centers on a surface of the catalyst [186]. In conditions of quasi-living polymerization there are no transfer reactions of the growing polymer chain and polymer is formed on the surface of catalyst in very small quantities. This polymer cannot cause diffusion restrictions, but nevertheless polymer with broad MMD (Mw/M = 3.2-4.3) is formed. The further increase in time of polymerization does not influence the width of MMD (M ,/M = 3.6). 

In this chapter we will discuss possible realizations of liquid crystalline ordering in conductive polymers. Section II presents basic properties of conducting polymers with a brief description of charge transport mechanisms in those systems. Section III discusses structural types and defects in liquid crystals, and Section IV covers some experimental results of the structural analysis of mesophases in polymers with flexible side chains and polymer/surfactant systems. Sections III and IV are presented to emphasize the properties important to conducting polymers. In Section V experimental data on liquid crystallinity in conductive polymers will be reviewed. Conclusion will be given in Section VI,... 

---