Sodium chloride swelling, hydrogels

Polyesters synthesized from terephthaloyl chloride and isohexides were prepared, and characterized by differential scanning calorimetry, n.m.r. spectroscopy, and viscosity measurement.25,128 Another polyester, prepared by copolymerization of (2-hydroxyethyl)methacrylate with isoman-nide dimethacrylate (172), forms a hydrogel when allowed to swell in isotonic sodium chloride solution. This gel has useful properties for manufacturing contact-lens material.265... 

A copolymer of this monomer with N,N melhylenebis (acrylamide) imbibed 100 times its weight of water. This swelling was not affected by sodium chloride in the water. Most super-slurpers swell less in the presence of dissolved salts. Thus, the new copolymer may be of use in collecting urine in diapers. Another polymeric hydrogel was made by polymerization of sucrose-l -acrylate using sucrose-6,1 -diacrylate (prepared by enzymatic transesterification of sucrose and vinyl acrylate) as the cross-linking agent.155... 

Figure 8. A. Effect of pH on the equilibrium degree of swelling of the hydrogels. B. Influence of sodium chloride concentration on the equilibrium degree of swelling. C. Effect of cation charge on the equilibrium degree of swelling of the hydrogels.

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