Dielectric properties, isotactic

These examples show that in certain cases (and under certain conditions) non electrostatic interactions can become a predominant factor controlling the state in solution of polyelectrolyte molecules. A very weak polyelectrolyte with a non hydrophylic chain can allow the illustration of such effects. A great deal of work has been carried out on polyanions but only a relatively limited number of studies is concerned with the properties of polycations. In this paper, we would like to present some properties concerning the polyelectrolytic behavior of aqueous solutions of (non quaternized) isomolecular atactic or isotactic poly-2-vinylpyridine (PVP), which have already been the subject of some of our previous investigations [4]. The experiments were performed on solutions without added salt with a few monovalent or bivalent counter-ions the effect of ionization and concentration on viscosimetric and dielectric properties of PVP was investigated. 

Fluorinated poly(methacrylates) or poly(acrylates), rich in trifluoromethyl groups, exhibit superior performance of chemical inertness, excellent weatherability, low refractive index, lower dielectric constant, and special surface properties [14,61]. Poly(2,2,2-trifluoroethyl methacrylate), poly(MATRIF), is an important class of such materials. It has been extensively used in high performance coatings [17], photoelectric communications, and microelectronics [62]. Poly(MATRIF) is easily produced by free radical polymerization using bulk, solution, and emulsion polymerization methods [63]. Structural characterization of NMR of poly(MATRIF) prepared by radical and anionic polymerization has been studied. Syndiotactic structure was obtained by radical initiator in contrast to an isotactic structure achieved by anionic polymerization [64]. 

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