How are polyacrylamides synthesized?

Abstract: Polyacrylamides of varying molecular weights (very low, low, medium, high and very high) were synthesized using free radical polymerization and characterized by Infra Red (IR) spectroscopy, viscosity measurements, glass transition temperature (Tg) measurement and thermal gravimetric analysis (TGA).

What are the initiators for polyacrylamide synthesis?

Thioglycolic acid and hydrogen peroxide were used as initiators to synthesis very low and low molecular weight polyacrylamides respectively. Molecular weights (medium, high and very high) polyacrylamides were synthesized using potassium persulfate and N,N,N',N'- tetramethylethylenediaminesystem as initiators.

How to synthesis high molecular weight polyacrylamides?

The synthesis of medium, high and very high molecular weight polyacrylamides were achieved by increasing the concentration of acrylamide monomer. Fourier Transform Infrared Spectroscopy (FTIR) of polyacrylamides showed strong absorption at wave number 1655 cm-1 due to the presence of primary amide band.

How does potassium persulfate/TMEDA system work in polyacrylamide synthesis?

Potassium persulfate/TMEDA system as initiator was used for the synthesis of medium, high and very high molecular weight polyacrylamides. TMEDA exerts a high promoting effect on the free radical polymerization initiated by potassium persulfate.

What is low molecular weight polyacrylamide?

Low molecular weight polyacrylamide was synthesized using hydrogen peroxide as initiator and the reaction was carried out at high temperature (90oC) to give polyacrylamide free of contaminates detected by FTIR spectroscopy. The product was a low viscosity white colour liquid.

Which polyacrylamide has the lowest stability?

On the other hand, very low molecular weight polyacrylamide displayed the lowest stability. The increase in molecular weight caused a decrease of weight loss %. The residue at 600oC being 11.67%, 14.68%, 17.83%, 19.45%, and 22.55% for the cases of very low, low, medium, high and very high molecular weight polyacrylamides respectively.