Polyelectrolyte-copolymers

New structural variants of crosslinked permeable polyelectrolytes, copolymers of AA or MA, and bi-or trivinyl comonomers with vinyl groups relatively distant from each other were obtained by predpitative copolymerization [16-21]. 

Siegel, R.A. Falamarzian, M. Firestone, B.A. Moxley, B.C. pH-controUed release hydrophobic/polyelectrolyte copolymer hydrogels. J. Control. Release 1988, 8, 179-182. 

Siegel RA, Falamarzian M, Firestone BA, Moxley BC. pH-controlled release from hydrophobic/polyelectrolyte copolymer hydrogels. J Contr Rel 1988 8 179-182. 

Q. Sun, M.-C. Park, and Y. Deng, Dendritic superstructure formation of polyanihne prepared using a water-soluble polyelectrolyte copolymer as the support matrix. Mater. Lett., 61, 3052-3055 (2007). 

Siegel, R. A., and Firestone, B. A., pH-dependent equilibrium swelling properties of hydrophobic polyelectrolyte copolymer gels. Macromolecules, 21, 3254-3259 (1988). Kuhn, W., Hargitay, B., Katchalsky. A., and Eisenberg, H., Reversible dilation and contraction by changing the state of ionization of high-polymer acid networks. Nature, 165, 514 (1980). 

The radius of gyration of the add form was found to be similar to that of the untreated polystyrene, but the of the salt form was greater than that of the add and increased with salt concentration. The increase in implied that the salt groups associated into clusters, distribution of cluster sizes was expected to be large, with an appreciable number of isolated ion pairs. The polyelectrolytic copolymer of styrene and methacrylic acid was found to cluster in the add form at high polymer concentrations, and R was found to decrease with increasing polymer concentrations in both the add and salt forms. ... 

In fact, the first systematic micellization studies of copolymers containing cationic hydrophilic blocks were those of Selb and Gallot, who have also given a review of this topic [190]. The typical polyelectrolyte copolymers investigated by these authors were polystyrene-b-poly(quaternized 4-vinylpyridine) PS-PQV4P with the following structure ... 

Berret JF, Cristobal G, Herve P, Oberdisse J, Grillo I (2002) Stmcture of colloidal complexes obtained from neufral/polyelectrolyte copolymers and oppositely charged surfactants. Eur Phys J E 9 301-311. doi 10.1140/epje/i2002-10063-7... 

Siegel, R. A., Falamarzian, M., Firestone, B. A. and Moxley, B. C. (1988). pH-con-trolled release from hydrophobic/polyelectrolyte copolymer hydrogels./oMmo/ of Controlled Release, 8,179-182. 

Siegel, R.A., Eirestone, B.A. pH-dependent equilibrium sweUiug properties of hydrophobic polyelectrolyte copolymer gels. Macromolecules 21, 3254—3259 (1988). doi 10.1021/ ma00189a021... 

Some commercial durable antistatic finishes have been Hsted in Table 3 (98). Early patents suggest that amino resins (qv) can impart both antisHp and antistatic properties to nylon, acryUc, and polyester fabrics. CycHc polyurethanes, water-soluble amine salts cross-linked with styrene, and water-soluble amine salts of sulfonated polystyrene have been claimed to confer durable antistatic protection. Later patents included dibydroxyethyl sulfone [2580-77-0] hydroxyalkylated cellulose or starch, poly(vinyl alcohol) [9002-86-2] cross-linked with dimethylolethylene urea, chlorotria2ine derivatives, and epoxy-based products. Other patents claim the use of various acryUc polymers and copolymers. Essentially, durable antistats are polyelectrolytes, and the majority of usehil products involve variations of cross-linked polyamines containing polyethoxy segments (92,99—101). 

Commercial grades of PVP, K-15, K-30, K-90, and K-120 and the quaternized copolymer of vinylpyrrolidone and dimthylaminoethylmethacrylate (poly-VP/ DMAEMA) made by International Specialty Products (ISP) were used in this study. PEO standard calibration kits were purchased from Polymer Laboratories Ltd. (PL), American Polymer Standards Corporation (APSC), Polymer Standards Service (PSS), and Tosoh Corporation (TSK). In addition, two narrow NIST standards, 1923 and 1924, were used to evaluate commercial PEO standards. Deionized, filtered water, and high-performance liquid chromatography grade methanol purchased from Aldrich or Fischer Scientific were used in this study. Lithium nitrate (LiN03) from Aldrich was the salt added to the mobile phases to control for polyelectrolyte effects. 

Photoresponsive polyelectrolytes tethered with a photochemical functional group were first reported in 1964 by Lovrien and Waddington [24] who prepared copolymers of iV-azobenzeneacrylamide and acrylic or methacrylic acid (1). 

The microphase separation of an amphiphilic polyelectrolyte is clearly reflected in the viscosity behavior of its aqueous solution. As a representative example, Fig. 5 shows the reduced viscosities of ASt-x with different styrene (St) content plotted against the polymer concentration in salt-free aqueous solution [29], The AMPS homopolymer and its copolymers with low St content exhibit negative slopes, which is the typical behavior of polyelectrolytes in the concentration range shown in Fig. 5. With increasing St content, however, the slope systematically decreases and eventually turns to be slightly positive, while reduced viscosity itself markedly decreases. These data indicate that, with increasing St content, the... 

As has been described in Chapter 4, random copolymers of styrene (St) and 2-(acrylamido)-2-methylpropanesulfonic acid (AMPS) form a micelle-like microphase structure in aqueous solution [29]. The intramolecular hydrophobic aggregation of the St residues occurs when the St content in the copolymer is higher than ca. 50 mol%. When a small mole fraction of the phenanthrene (Phen) residues is covalently incorporated into such an amphiphilic polyelectrolyte, the Phen residues are hydrophobically encapsulated in the aggregate of the St residues. This kind of polymer system (poly(A/St/Phen), 29) can be prepared by free radical ter-polymerization of AMPS, St, and a small mole fraction of 9-vinylphenanthrene [119]. 

The salt effect is very strong in polyconjugated polyelectrolytes. Figure 15 is a graph of the proton dissociation energy vs. the dissociation degree of PPA of different structures. Also, the graphs for poly(methacrylic acid) and a copolymer... 

Fig. 15. Energy of proton dissociation (Ez) from Z times ionized polyelectrolyte molecules as function of the degree of dissociation (a). (A) - PPAL (1), PPAS (2), PPA (3), polyfmethacrylic acid) (4), copolymer of acrylic acid with ethylenesulfonic acid (50 50) in aqueous solutions (5), (B) - PPAL (1), PPAS (2), PPA in the presence of NaCl (3) ( ) INaClj = 0 (X) fNaCll = 0.25 mmol/1 (o) 0.50 mmol/1...

Corner, T. Free Radical Polymerization — The Synthesis of Graft Copolymers. Vol. 62, pp. 95-142. Crescenzi, V. Some Recent Studies of Polyelectrolyte Solutions. Vol. 5, pp. 358-386. 

AB cements are not only formulated from relatively small ions with well defined hydration numbers. They may also be prepared from macromolecules which dissolve in water to give multiply charged species known as polyelectrolytes. Cements which fall into this category are the zinc polycarboxylates and the glass-ionomers, the polyelectrolytes being poly(acrylic acid) or acrylic add copolymers. The interaction of such polymers is a complicated topic, and one which is of wide importance to a number of scientific disciplines. Molyneux (1975) has highlighted the fact that these substances form the focal point of three complex and contentious territories of sdence , namely aqueous systems, ionic systems and polymeric systems. 

Polyelectrolytes are polymers having a multiplicity of ionizable groups. In solution, they dissociate into polyions (or macroions) and small ions of the opposite charge, known as counterions. The polyelectrolytes of interest in this book are those where the polyion is an anion and the counterions are cations. Some typical anionic polyelectrolytes are depicted in Figure 4.1. Of principal interest are the homopolymers of acrylic acid and its copolymers with e.g. itaconic and maleic adds. These are used in the zinc polycarboxylate cement of Smith (1968) and the glass-ionomer cement of Wilson Kent (1971). More recently, Wilson Ellis (1989) and Ellis Wilson (1990) have described cements based on polyphosphonic adds. 

The chemistry of polyelectrolyte cement liquids has been studied using NMR. Watts (1979) used this technique to distinguish between the homopolymer of acrylic acid and its copolymer with itaconic acid in various commercial polyelectrolyte dental cements. This was readily achieved because of the ability of NMR to differentiate between carbon atoms in chemical environments that are only slightly different. 

Poly(starch-g-(l-amidoethylene)) copolymer is not a polyelectrolyte and will be a smaller molecule in water than an equal molecular weight, partially hydrolyzed poly(l-amidoethylene). Polyelectrolyte effect should, however, cause the graft copolymer to expand in solution in the same way it causes poly(l -amidoethylene) to expand, so a series of hydrolyzed graft copolymers were prepared from poly(starch-g-(l-amidoethylene))(41-43) and these derivatives were tested to determine the effect of hydrolysis on copolymer properties in solution. 

Results and Discussion. Of the 12 samples of starch graft copolymer synthesized, half were hydrolyzed to anionic polyelectrolytes. Synthesis data on these 6 samples are given in Table 2. These particular samples were chosen for hydrolysis because the samples can be intercompared to see the effect of synthesis variables on ultimate product properties. Samples 5, 8, and 11 have the same mole ratio of cerium ion to starch backbone, N, in their reaction mixture. Samples 7, 8, and 9 all have the same refctable mass per starch molecule,... 

---