Zwitterionic sulfonate monomers

This chapter describes the synthesis, kinetics, and solution properties for copolymers ofN-vinylpyrrolidone (NVP) with sulfonate ionic and zwitterionic monomers. Examples of the sulfonate ionic monomers are sodium styrenesulfonate (NaSS) and sodium acrylamido-2-meth-ylpropanesulfonate (NaAMPS) an example of the zwitterionic sulfonate monomer is 2-hydroxyethyt)dimethyl(3-sulfopropyt)-ammonium inner salt, methacrylate (SPE). The NVP-NaAMPS monomer pair was exceptional, showing evidence for donor-acceptor character and an alternating tendency in copolymerization. The NVP copolymers containing simple sulfonate ionic monomers e.g., NaAMPS) showed polyelectrolyte solution properties. On the other hand, the NVP copolymers with zwitterionic sulfonate monomers showed antipoly electrolyte solution behavior. 

In copolymers containing the styrene sulfonate moiety and maleic anhydride units, the maleic anhydride units can be functionalized with alkyl amine [1411-1416]. The water-soluble polymers impart enhanced deflocculation characteristics to the mud. Typically, the deflocculants are relatively low-molecular-weight polymers composed of styrene sodium sulfonate monomer maleic anhydride, as the anhydride and/or the diacid and a zwitterionic functionalized maleic anhydride. Typically the molar ratio of styrene sulfonate units to total maleic anhydride units ranges from 3 1 to 1 1. The level of alkyl amine functionalization of the maleic anhydride units is 75 to 100 mole-percent. The molar concentrations of sulfonate and zwitterionic units are not necessarily equivalent, because the deflocculation properties of these water-soluble polymers can be controlled via changes in their ratio. 

I EW SULFONATE MONOMERS, both the simple ionic [e.g., sodium styrenesulfonate (NaSS) and sodium acrylamido-2-methylpropanesulfonate (NaAMPS) (i)], and zwitterionic [e.g., (2-hydroxyethyl)dimethyl(3-sulfopro-pyl)ammonium, inner salt, methacrylate (SPE) (2)] types, have recently become available. Homopolymers of such simple sulfonate monomers are characterized by good thermal and hydrolytic stability however, their so-... 

The rates of polymerization (R ) for the copolymerization of NVP and the various sulfonate monomers (simple ionic and zwitterionic) as a function of sulfonate content are shown in Figure 1. The for the copolymerization of NVP with the sulfonate monomers is... 

The zwitterionic sulfonates (sulfobetaine monomers) also show a higher... 

Salt-tolerant polyampholytes with potential for viscosity maintenance (or increase) at low concentration in the presence of simple electrolytes such as NaCl include polymers formed by equamolar incorpomtion of sulfonate and quaternary ammonium mer units (Type A) or those formed by the copolymerization of a zwitterionic sulfobetaine monomer with a water-soluble monomer (Type B) as shown in Scheme 1. Usually, a water-soluble mer unit, W, is included for adequate hydration. Key features of polyampholytes from sulfonated quaternary ammonium monomers (Types A and B) are discussed here, although corresponding carboxylate (4-9), phosphonate (10-14), or tertiary ammonium derivatives have been syndiesized and are responsive to pH. 

Other copolymers of acrylamide with the zwitterionic 3-(2-acrylamido-2-methylpropyldimethyl ammonio)- -propane sulfonate (AMPDAPS) monomer also have been examined. 

Water soluble block copolymers consisting of N-isopropylacrylamidc, NIPA, and the zwitterionic monomer 3-[N-(3-methacrylamidopropyl)-N,N-dimethyl]ammoniopropane sulfonate, SPP, were prepared via the RAFT process [82] (Scheme 31). NIPA was polymerized first using AIBN as the initiator and benzyl dithiobenzoate as the chain transfer agent. To avoid the problem of incomplete end group functionalization the polymerization yield was kept very low (less than 30%). The block copolymerization was then performed... 

Zwitterions are spontaneously formed by reaction of nucleophilic monomers such as cyclic exo and endo imino ethers, azetidines, cyclic phosphites, and Schiff bases on the one hand, with electrophilic monomers like lactones, cyclic anhydrides, sulfones, and acrylic compounds on the other hand (Table 22-6), that is, either from two suitable heterocyclic compounds or from a heterocyclic compound and an acrylic compound. According to reaction partners, the reaction already occurs at room temperature or only after heating. 

Polyzwitterions (Type B) containing the sulfonate functionality have been thoroughly studied beginning with the pioneering work of Hart and Timerman (3J). In that work, zwitterionic monomers were prepared by the reaction of 2-and 4-vinylpyridine with 1,4-butanesultone. Polysulfobetaines are typically insoluble in deionized water and require a relatively high content of hydrophilic comonomer or the addition of a critical concentration of electrolyte to achieve solubility and viscosity enhancement. Polysulfobetaines have also been synthesized from acrylic (32-36), acrylamido (37), and vinyl imidazolium (38,39) monomers. 

Poly-zwitterions differ from polyampholytes in that both the cationic and anionic species are on the same monomer residue, consisting of a quaternary ammonium, which is a cationic moiety, and sulfonate (sulfobetaines), carboxylate (carbo- or... 

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