Polyacrylic acid chemical structure

Among the chemically-defined macromolecular stimulators of interferon production are the synthetic polymers derived from ethylene maleic anhydride or polyacrylic acid. The structural requirements appear to be a molecular weight of 17,000 or greater and a saturated aliphatic carbon chain with carboxylated groups in alternate or adjacent positions on two out of every four or five carbons. These einionic copolymers are active in vivo in mice against Friend leukemia virus and stimulate the produc tion of interferon in man. 

Polyacrylic acid (PAA) was obtained from Scientific Polymers, Inc., Ontario, NY, as a secondary standard with a mass-averaged molecular weight of two million. The polyacrylamide (PAM) used was Separan MGL obtained from Dow Chemical Company, Midland, MI. Its reported molecular weight was in the range of 500,000 to 5,000,000. The monomer structures of PAA and PAM are illustrated in Figure 1. 

Figure 1. Chemical structure of polyacrylic acid and polyacrylamide monomers and sodium dodecylsulfonate.

In this chapter, approaches to estimates of (1) the polyelectrolyte (electrostatic) effect, (2) the hydrophobicity/hydrophilicity effect, and (3) the multicoordination effect, specified for metal ion/polyelectrolyte systems are described. As weak acidic polyelectrolytes, polyacrylic acid, PAA, as well as polymethacrylic acid, PMA, are exemplified as an example of weak basic polyelectrolyte, poI y(/V-vinyI i m idazoIc), PVIm, is chosen all the chemical structures of the polymer ligands are illustrated in Figure 1. Precise poten-tiometric titration studies by the use of a glass electrode as well as respective metal ion selective electrodes have been performed for the complexation equilibrium analyses. All the equilibrium constants reported in this chapter were obtained at 298 K unless otherwise stated. 

Using functional molecules as structural directors in the chemical polymerization bath can also produce polyaniline nanostructures. Such structural directors include surfactants [16-18], liquid crystals [19], polyelectrolytes (including DNA) [20,21], or complex bulky dopants [22-24]. It is believed that functional molecules can promote the formation of nanostructured soft condensed phase materials (e.g., micelles and emulsions) that can serve as soft templates for aniline polymerization (Figure 7.3). Polyelectrolytes such as polyacrylic acid, polystyrenesulfonic acid, and DNA can bind aniline monomer molecules, which can be polymerized in situ forming polyaniline nanowires along the polyelectrolyte molecules. Compared to templated syntheses, self-assembly routes are more scalable but they rely on the structural director molecules. It is also difficult to make nanostructures with small diameters (e.g., <50 nm). For example, in the dopant induced self-assembly route, very complex dopants with bulky side groups are needed to obtain nanotubes with diameters smaller than 100 nm, such as sulfonated naphthalene derivatives [23-25], fidlerenes [26], or dendrimers [27,28]. 

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