Styrene sulfonate monomers, synthesis

Synthesis and Emulsion Copolymerizations of Styrene Sulfonate Monomers for Cross-Linked Polyampholyte Latexes... 

Postsulfonation of polymers to form PEMs can lead to undesirable side reactions and may be hard to control on a repeatable basis. Synthesis of sulfonated macromolecules for use in PEMs by the direct reaction of sulfonated comonomers has gained attention as a rigorous method of controlling the chemical structure, acid content, and even molecular weight of these materials. While more challenging synthetically than postsulfonation, the control of the chemical nature of the polymer afforded by direct copolymerization of sulfonated monomers and the repeatability of the reactions allows researchers to gain a more systematic understanding of these materials properties. Sulfonated poly(arylene ether)s, sulfonated poly-(imide)s, and sulfonated poly(styrene) derivatives have been the most prevalent of the directly copolymerized materials. 

Figure 2.8. The formation of a styrene-acetylene diblock copolymer and random copolymers of acetylene and phenyl vinyl sulfone using the anionic precursor method. The synthesis of the phenyl vinyl sulfoxide and phenyl vinyl sulfone monomers is also shown.

The first involved selective functionalization of a preformed polymer. Block prepolymers of styrene and t-butyl styrene were prepared by anionic polymerization and then functionalized by sulfonating the styrene units. The anionic polymerization and sulfonation techniques used to prepare these polymers and the chromatographic techniques used to characterize molecular weight and distribution were well developed. Sulfonation was clean, essentially complete and selective to the para position of the styrene monomer due to the blocking of this position by the t-butyl groups of the t-butyl styrene monomer. The synthesis and... 

Copolymerization of styrene with small amounts of bifunctional monomers such as divinylbenzene is used for the synthesis of networks. The polymerization technique of choice is bead polymerization. Polymer porosity can be controlled by the addition of polystyrene, which can be extracted after polymerization has been completed. Sulfonation of such networks yields cation-exchange resins anion-exchange resins can be synthesized... 

At present, many sulfonated derivatives of polymers such as poly(ether ether ketone), polysulfone, poly (ary lene ether snlfone), poly(styrene), and polyCphenylene sulfide) have been developed for fnel cells [10-14], More recently, the synthesis of sulfonated poly(arylene ether snlfone) and/or snlfonated poly(arylene ether ketone)s copolymers by direct copolymerization of biphenol, disnlfonated-activated aromatic halide monomers, and the precnrsor—activated aromatic halide monomer for fnel cell membrane applications— were carried ont [12,15],... 

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