Ionic side group

In addition to alkyl-substituted derivatives, soluble PPPs 6 are also known today containing alkoxy groups as well as ionic side groups (carboxy and sulfonic acid functions) [18]. Schliiter et al. recently described the generation of soluble PPPs decorated with densely packed stcrically demanding dendrons on the formation of cylindrically shaped dendrimers, so-called cylinder dendrimers ] 19]. 

The polymer forms a stable monolayer on the surface of water. The surface pressure-area diagram of the monolayer is shown in Figure 7.1, where the surface area S is calculated per ionic side group. The collapse pressure ofthe monolayer is equal to 54 mN/m. 

Fig. 2 Examples of photosensitizers presently approved for clinical applications or in clinical studies. mTHPC, tetra (meso-hydroxy) phenyl chlorin BPD-MA, benzoporphyrin derivative Photofrin is a mixture of several compounds where dimers or trimers of the indicated structure are assumed to be of major importance PpIX, protoporphyrin IX - accumulating upon treatment with 5-aminolevulinic acid or its ester derivatives, NPe6, HPPH, Hexyl pyropheophorbide TPPS2a, disulfonated (adjacent) tetraphenylporphin AlPcS2a, disulfonated (adjacent) aluminum phthalocyanine. Areas with ionic side groups are indicated in shadow...

Polysiloxanes with hydrogen atoms on the main chain are also modified by hydrosilylation with allyl glycidyl ether. The epoxy side groups may then be transformed into ionic substituents, as illustrated in Scheme 3. The resulting polysiloxanes with ionic side groups have good properties as hair and textile conditioners. 

More recently, the Cole-Hamilton group has been able to develop a continuous-flow process on the basis of a similar concept, using phosphine ligands modified with ionic side groups to disperse and immobilize the catalyst in the liquid product phase [5]. 

For the purposes of delineating the scope of the membrane systems considered in this chapter, the generic PFSI chemical structure is defined in Figure 13.1, following the notation used by Tant et al. [1]. All the structures have a common feature they consist of a (presumed) random copolymer of tetrafluoroethylene and perfluorovinyl ether monomer units but differ in terms of the length and distribution of the ionic side groups along the main... 

The solubilization of PPP-type polymers was possible by the introduction of alkyl, alkoxy, ester, keto, or ionic side groups in a hairy rod approach initially developed by Schliiter and Wegner and coworkers [44-64]. Moreover, important progress has been made in the development of effective and selective aryl-aryl coupling methods toward structurally defined, soluble PPP derivatives. 

Hsiao, E. Kim, D. Kim, S. H., Effects of Ionic Side Groups Attached to Polydimethylsiloxanes on Lubrication of Silicon Oxide Surfaces. Langmuir 2009, 25, 9814-9823. 

Polyelectrolytes are polymers with ionic side groups. The coil expansion of polyelectrolytes is not only determined by the usual parameters molar mass, solvent quality and temperature, but also by the degree of dissociation of the ionic groups. An example for a polyelectrolyte is the poly(acrylic acid) (PAAc) or its sodium salt (PAAcNa). The reduced viscosity of this polyelectrolyte is plotted as a function of the concentration c in Fig. 5.14. At high concentrations, the reduced viscosity decreases with a decreasing concentration as expected for a polymer solution. However, at lower concentrations the reduced viscosity levels into a plateau and increases again with a decreasing concentration. 

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. 

Self-dopant systems [36] with ionic side groups or CT-complexing in the main chain... 

Soluble PPPs not only contain alkyl substituents, they were also synthesized with alkoxy groups and with ionic side groups like carboxy and sulfonic acid functions, which are able to form PPP polyelectrolytes [71]. 

Michaels et al. concluded from their results that the permittivity spectra mostly arise from minor displacements of the ionic side groups of the macromolecules. Traces of small ions, which are also present in nominally intrinsically compensated complexes, are claimed to be also involved in these local motions, but then-long-range mobility is rather small. Water loosens the structure and facilitates ion motion. 

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