Halato-telechelic polymers

Note 1 The term halato-telechelic polymer is used to denote a polymer composed of macromolecules having stable (long-lived) ionic or ionizable groups, such as carboxylate... 

Note 2 The term halatopolymer is used for a linear polymer formed by the coupling of halato-telechelic polymer molecules, for example, for the linear polymer formed by the coupling of carboxylate end-groups with divalent metal cations [2]. 

That concept had led to the synthesis of so-called "halato-telechelic polymers" (which means a "salt" or "neutralized" telechelic polymer, acidic or basic). Although that is a very general denomination covering all the chains formed by any type of ion-pair coupling in any way, a particularly handy and representative class of such structures can be obtained from the complete neutralization of a,o)-dicarboxylato-polymers (PX), by a di (or multi-) valent metal derivative, (19), according to the general equation ... 

ASSOCIATION OF THE ION PAIR END-GROUPS OF HALATO TELECHELIC POLYMERS IN NONPOLAR SOLVENTS... 

During the 1970s and 1980s, several novel ionomer systems have been developed. Of particular interest are the perfluorinated resins and halato-telechelic polymers as well as the various sulfonated materials. These systems will be discussed in greater depth in the following sections. 

In general, the preparation of ionomers is a straightforward procedure. The particular acid group of interest can be introduced onto the hydrocarbon backbone either by direct copolymerization or post-synthesis reaction. The following five important groups of ionomers illustrate the various methods of preparation. These ionomer families are ethylene-based materials, ionic elastomers, modified polystyrenes, perfluorinated resins and halato-telechelic polymers. 

The synthesis of low molecular weight difunctional carboxyl-terminated butadiene-based polymers via either free radical or anionic polymerization is well established. Teyssie and co-workers have converted such carboxyl-terminated polymers to salt forms, which they refer to as halato-telechelic polymers, by neutralization with metal alkoxides in appropriate solvents. The quantitative removal of low molecular weight reaction products is necessary to drive the reaction to completion and fully realize the ionomeric properties of these materials. 

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