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Handbook of Size Exclusion Chromatography and Related ...

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Acrylamidecansimultaneouslyreactwithanionic<strong>and</strong>cationicmonomerst<strong>of</strong>orm<br />

apolyampholyte.Theacrylamidehomopolymer,copolymers,<strong>and</strong>terpolymersare<br />

synthesized (1–20) by free radicals via solution or emulsion or other<br />

polymerization methods. Adamsky <strong>and</strong> Beckman (21) reported the inverse<br />

emulsion polymerization <strong>of</strong> acrylamide in supercritical carbon dioxide. The<br />

product classes <strong>of</strong> acrylamide polymers include liquid, dry,<strong>and</strong> emulsion.<br />

Thenonionic,anionic,<strong>and</strong>cationicacrylamidepolymershavebeenusedfor<br />

many industrial applications (1–3,13,22,23). The polymer selection for a<br />

particular application depends upon the desired chemical structure, chemical<br />

composition,molecularweight(MW),<strong>and</strong>molecularweightdistribution(MWD).<br />

Some applications <strong>of</strong> acrylamide polymers are shown in Table 1. <strong>Size</strong> exclusion<br />

chromatography (SEC) is an excellent technique to determine MW <strong>and</strong> MWD.<br />

Yau et al. (24) have discussed the SEC technique. Barth (25) has reported a<br />

practical approach to steric exclusion chromatography <strong>of</strong> water-soluble polymers.<br />

However, SEC is not easily carried out for the subject polymers because <strong>of</strong> the<br />

high molecular weight (10 6 –10 7 g/mole) <strong>and</strong> the polyelectrolyte characteristics<br />

<strong>of</strong> the charged polymers. In order to obtain meaningful SEC data, the columns,<br />

mobile phase, concentration <strong>of</strong> polymer solution, sample preparation method,<br />

flow rate, <strong>and</strong> shear degradation <strong>of</strong> the polymer should be considered in an<br />

SEC experiment.<br />

Several authors (26–29) have discussed concentration effects in SEC.<br />

Barth <strong>and</strong> Carlin (30) have proposed mechanisms <strong>and</strong> possible sources <strong>of</strong><br />

polymer shear degradation in SEC. Giddings (31) determined the shear<br />

degradation <strong>of</strong> PAM. Omorodion et al. (32) studied the effects <strong>of</strong> pH, ionic<br />

strength, <strong>and</strong> nonionic surfactants on polymer dimensions <strong>and</strong> elution volume for<br />

aqueous SEC <strong>of</strong> PAM with controlled-porc glass (CPG) columns. Onda et al.<br />

(33,34) analyzed PAM by SEC using CPG columns in formamide <strong>and</strong> aqueous<br />

media. They also studied the effects <strong>of</strong> salt addition on the retention volume.<br />

Klein <strong>and</strong> Westerkamp (35) separated PAM, acrylamide/sodium acrylate<br />

copolymers, dextrans, <strong>and</strong> poly(sodium styrene sulfonates) by using CPG<br />

columns. They investigated the thermal degradation <strong>of</strong> PAM at 50 <strong>and</strong> 758C.<br />

Letot et al. (36) used polyvinylpyrrolidone-coated silica columns <strong>and</strong> pure<br />

water to chromatograph PAM <strong>and</strong> other water-soluble polymers. El-Awady <strong>and</strong><br />

co-workers (37) investigated the MW <strong>and</strong> MWD <strong>of</strong> PAM in side chains <strong>and</strong> in<br />

homopolymer by SEC during grafting <strong>of</strong> cellulose acetate with acrylamide<br />

monomer. McCormick <strong>and</strong> Park (38) studied the effects <strong>of</strong> Fe(II), H2O2,<br />

acrylamide, <strong>and</strong> dextran concentration on the hydrodynamic volumes <strong>of</strong> dextrangrafted<br />

acrylamide copolymers by SEC. Muller <strong>and</strong> Yonnet (39) studied a high<br />

MW hydrolyzed polyacrylamide (HYPAM) <strong>and</strong> a 74/26 mole% AM/AA high<br />

MW copolymer by SEC, static low-angle laser light scattering (LALLS) <strong>and</strong><br />

photon correlation light scattering. Huang (40) evaluated the chemical structural<br />

heterogeneity <strong>of</strong> cationic acrylamide copolymers by high-performance liquid<br />

© 2004 by Marcel Dekker, Inc.

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