Preparation and characterization of a series of poly(acrylamide-co-acrylates), with a copolymer composition between 0?96.3 mol-% acrylate units with the same degree and distribution of polymerization

Abstract

A series of linear poly(acrylamide-co-acrylates) (PAAm/AAcNa) has been prepared covering a copolymer composition between 0 and 96.3 tool0/0 acrylate units, which have the same degrees of polymerization and chain length distributions. Measurements of viscosity and light scattering have proven that maximum coil dimensions of PAAm/ AAcNa in salt solutions are achieved at about 67 mole-% AAcNa. This so-called maximum behaviour was researched by measuring the radius of gyration, second virial coefficient, molecular weight, preferential solvation, viscosity and absorption bands of the copolymer series. Thus, an increase in the possible ways of arranging AAcNa-AAmAAcNa units (via H-bonds) will lead to extended coil dimensions and therefore influence the viscosity. In addition, it can therefore be concluded from all these results that the maximum behaviour is real and not influenced by the different distributions of the samples. The copolymer composition can be easily determined by infra-red spectroscopy by use of a proposed relation.

Water-Soluble Copolymers. 68. Polyelectrolytes of N-Vinylformamide with Sodium 3-Acrylamido-3-methylbutanoate, Sodium 2-Acrylamido-2-methylpropanesulfonate, and Sodium Acrylate: Solution Behavior

“…This has been previously observed for copolymers of AM and NaA. [13][14][15] Another effect which influences solvation of polyelectrolytes is that of counterion condensation, which effectively neutralizes a portion of the anionic charge, thereby reducing charge repulsion effects. Intramolecular hydrogen bond- ing, counterion condensation, and charge-charge repulsions are stronger with the AAVF series, in which the anionic group is closer to the macromolecular backbone.…”

A method for measuring the degree of anionicity of polyacrylamide-based flocculants

“…Band assignments can be found in Guerrero et al (1985), Kulicke and Hörl (1985), and Lu and Mi (2005). The 3200-3400 cm − 1 range is associated with the symmetrical and asymmetrical stretching modes of the N-H bonds in amide (NH 2 ) groups, although water molecules also give a broad band centered around a wavenumber of 3450 cm − 1 .…”

“…Films of each polymer were prepared at two pH values: pH 3 (HCl) and pH 6-7 (natural). Once the spectra were collected, an empirical formula proposed by Kulicke and Hörl (1985) was employed to calculate approximate values of the degree of anionicity. The formula has the following form:…”

“…The most relevant methods, and combinations thereof, usually employ infrared spectroscopy (Guerrero et al, 1985;Kulicke and Hörl, 1985;Rogers and Poling, 1978;Tackett, 1990), potentiometric acid-base titration (Muller et al, 1979(Muller et al, , 1980, C 13 NMR (nuclear magnetic resonance) spectroscopy (Halverson et al, 1985;Leung et al, 1985;Zurimendi et al, 1984) and elemental analysis (Kulicke and Kniewske, 1981). A detailed review of the published methods and results is beyond the scope of this study, but the following observations and comments need to be made in order to place our results in the context of what has been published so far.…”

Characterization of poly(acrylamide-co-acrylates) obtained by inverse microemulsion polymerization

“…The decrease of viscosity observed at higher ionic strength is then caused by the enhancement of electrostatic repulsions between carboxylates groups which prevent the formation of intramolecular Hbonds. More recently Kulicke and Htrl [25] have confirmed this analysis and shown that this maximum behavior was still present for a series ofpoly(acrylamideco-acrylates) covering a wide range of composition and with the same degree and distribution of polymerization. Although we did not determine the molecular weight of our samples by light scattering, we can still assume that they are not significantly affected within the same series where only the comonomer composition is varied.…”