Ionic strength terpolymers

Terpolymer solution behavior is dependent on compositional microstructure, polymer concentration, ionic strength, pH, temperature, and shear history. The viscosities of these low charge density terpolymers would be expected to be insensitive to changes in ionic strength below the critical overlap concentration, C above C intermolecular attractive forces might be expected to cause enhanced viscosities similar to those of hydrophobically associating copolymers. 

Effects of Ionic Strength. Figure 13 illustrates the effect of NaCl concentration on intrinsic viscosity for each terpolymer. Of course, this experiment should demonstrate only the effects of added electrolyte on individual chain contraction or expansion. The chains with sufficient monomer pairs exhibit increases in viscosity as expected with addition of NaCl. The best chain expansion is seen for the 5-5 sample, which is rapidly solvated with increasing ionic strength. The 5-10 sample shows some typical polyelectrolyte behavior because it has an excess of macroanions at pH 7. 

Commercial ionomers are ethylene-methacrylic acid copolymers and terpolymers in which the carboxylic acid moiety is partially neutralized with sodium or zinc, to promote interchain ionic bonding. Ionomers exhibit excellent low temperature toughness, chemical resistance and adhesion. However they lack in stiffness and heat resistance. Hence ionomer blends with polyolefins such as polyethylene have been developed which, upon reinforcing with suitable fillers, seem to give a unique combination of high strength, excellent low temperature toughness, and moderate stiff-... 

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