How to measure anionicity of polyacrylamide based flocculants?

A simple procedure was described for routine measurements of the degree of anionicity of polyacrylamide-based flocculants. The method relies on determining the total organic carbon content and assaying ion concentrations in a dilute solution (in distilled water at natural pH) of the tested flocculant.

How to determine the viscosity average molecular weight of polyacrylamide samples?

Dilute solution viscosity method was used to determine the viscosity average molecular weight of the polyacrylamide samples by determining their intrinsic viscosities. Test sample was prepared by dissolving 0.5g of polyacrylamide in 100 ml distilled water at room temperature using magnetic stirrer.

Does intrinsic viscosity affect molecular weight of polyacrylamide?

Intrinsic viscosity of the very low, low, medium, high and very high polyacrylamides samples were obtained.The results of intrinsic viscosity and viscosity average molecular weight are tabulated in table 2. It can be seen that the increase in the intrinsic viscosity was proportional to the increase in molecular weight of polyacrylamide.

What is the degree of anionicity of polyacrylamide?

The ratio of the number of acrylic monomer units to the total number of acrylic and acrylamide units is known as the degree of anionicity (DA), or the degree of substitution (DS). Fig. 1 and Eq. (1) illustrate the structure of hydrolyzed polyacrylamide and the definition of the degree of anionicity, respectively. (1) D A = 100 % × n / (n + m)

How does polyacrylamide concentration affect viscosity?

It was found that by increasing the polyacrylamide concentrations from 1×10-3 to 5×10-3g/ml the efflux time increased. As a result, the relative viscosity increased with an increase in the polyacrylamide concentration. Other viscosities namely specific and reduced viscosities also increased with an increase in the polyacrylamide concentration.

Which peaks are used to determine anionicity of polyacrylamide flocculants?

The peaks at 1452 cm −1 and 1410 cm −1 were used by Rogers and Poling (1978) to determine the degree of anionicity of polyacrylamide flocculants by comparing with spectra and band intensities of standard polymers of known anionicity.