Ionic polymers polycarboxylates

The interaction between ionic polymers and nonionic surfactants has not received as much attention as the other cases discussed in the preceding sections. Much of the earlier research in this area has been focused on the interaction of anionic polymeric acids with nonionic surfactants of polyethylene oxide. The polyethylene oxide has shown the ability to form hydrogen bonds with polymeric acid like polycarboxylic acid in water. This canses a redaction in the solution viscosity as the polymer chains tend to shrink. Saito and Taniguchi (1973) studied the interaction of polyacrylic acid with a series of nonionic surfactants (EO) RE in which EO is ethylene oxide, R is hydrocarbon group, and E represents ether. They reported that the interaction in this system is a function of the nature of the hydrophobic moiety (R) and the length of the hydrophilic tail (EO). 

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. 

The excitation and emission spectra of lanthanide metal ions, such as Tb(Ill) or Eu(III) in polycarboxylates (ionic interaction), have been investigated in detail [28,29]. The purpose was to study the structure of ionomers in solution and as solids. The linear increase of the luminescence intensity with increasing concentrations of lanthanides in a polymer film indicates a mononuclear distribution at lower concentrations. In a copolymer of styrene and acrylic acid a decrease of the luminescence intensity at > 4-6 wt%, and in poly(acrylic acid) or poly(styrene-co-maleic acid) at > 15 wt%, indicates the formation of ionic aggregates [30]. 

Studies on the interaction between surfactants and styrene-ethylene oxide block co-polymers, however, indicate that the polymers exhibit, in the presence of surfactant, typical polyelectrolyte character. This, it has been suggested [264], is due to interaction repulsions between like charges of the NaDS ions adsorbed onto the polyoxyethylene blocks. Investigating the interaction of the same detergent with methylcellulose and poly(vinyl alcohol), Lewis and Robinson [265] also observed the polyelectrolyte character of the polymer-surfactant complexes. A complex between non-ionic surfactants and a polycarboxylic acid in water can solubilize oil-soluble dyes below the surfactant CMC [268]. The complex containing the solubilizate can be precipitated the solubilizate remains in the precipitated complex and is leached out only slowly on placing the precipitate in fresh solvent. This has potential pharmaceutical implications. Halothane uptake by coacervate systems of gelatin-benzalkonium [269] has... 

In addition, polymers with free carboxylic acid groups such as PAA and poly(methacrylic acid) can form copolymer electrolytes with PEO, leading to a sharp increase in ionic conductivity. Apparently, the PAA or other polycarboxylic acids can increase the lithium-ion transference number by decreasing the transfer of anions. The ionic conductivities of these copolymer electrolytes can be further increased by adding boron trifluoride diethyl etherate (Bp30Et2), which can promote the dissolution of lithium cations and carboxylic acid anions. Epoxidized natural rubber can also increase the ionic conductivity of PEO. Addition of symmetric poly(styrene-Wocfc-ethylene oxide) copolymers obviously affects the distribution of Lb ions. In contrast to current solid and liquid electrolytes, its ionic conductivity increases with increasing molecular weight of the copolymers. 

Chem. Descrip. Polycarboxylate polymer type Ionic Nature Anionic... 

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