Nonionic polymers, chemical structure

The nonionic, anionic, and cationic acrylamide polymers have been used for many industrial applications (1, 2, 3, 13, 22, 23). The polymer selection for a particular application depends upon the desired chemical structure, chemical composition, molecular weight (MW), and molecular weight distribution (MWD). Some applications of acrylamide polymers are shown in Table 1. Size... 

Migratory antistats (MAS). Migratory antistats have chemical structures that are composed of hydrophilic and hydrophobic components. These materials have limited compatibility with the host plastic and migrate or bloom to the surface of the molded product. The hydrophobic portion provides compatibility within the polymer and the hydrophilic portion functions to bind water molecules onto the surface of the molded part. If the surface of the part is wiped, the MAS is temporarily removed, reducing the antistat characteristics at the surface. Additional material then migrates to the surface until the additive is depleted. These surface-active antistatic additives can be cationic, anionic, and nonionic compounds. 

Figure 1. Chemical structures of the polyelectrolytes and nonionic polymers employed in this study.

The chemical structures of the nonionic and anionic polymers are shown in Fig. 2. The main chemical structure is poly(acrylamide). Depending on the characteristics of the wastewater and treatment conditions, hydrolysis or copolymerization with acrylic acid is carried out to adjust anion concentrations (0-100mol%). In addition to carboxylic acid a sulfonic type is also used. 

Polymer solution viscosity is an important physical property in polymer research, development, and engineering. When high molecular weight nonionic polymer molecules dissolve in a fluid, they typically expand to form spherical coils. In dilute solutions, the volume associated with each polymer coil contains one polymer molecule surrounded by a much larger mass of solvent. A polymer coil s hydrodynamic volume depends upon the polymer molecular weight and its thermodynamic interaction with the solvent. Polymer-solvent interactions depend upon the polymer molecular structure, chemical composition, solution concentration, solvent molecular structure, and the solution temperature. 

A nonionic, non-volatile photoactive acid generator, 2,6-dinitrobenzyl tosylate has been recently reported and shown to be effective in chemically amplified resist systems (10). This ester is a nonionic compound that has a much wider range of solubility in matrix polymers and does not contain undesirable inorganic elements. While it is known to exhibit a lower sensitivity to irradiation than the onium salt materials, many structural variations can be produced to precisely vary the acid properties of the molecule and to control the diffusion of the AG in the polymer matrix (11). 

The nature of the association maintains a locally effective shielding of the sulfonate anions within the aggregate and preservation of the clustered structure. This suggests that for these block polymer structures, the energetics of maintaining hydrophobic association are more favorable than monomer dispersion due to ionic repulsion. This was further demonstrasted by the extreme salt sensitivity of these polymers to solution ionic strength. Small amounts of sodium chloride resulted in polymer precipitation and of course loss of viscosification. This precludes the use of these particular polymers for chemically enhanced oil recovery and indicates the need for nonionic functionality to provide water solubility. To further pursue this approach acrylamide based polymers were studied. 

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