Synthesis and Characterization of Different Molecular Weights Polyacrylamide

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). 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. 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. The results also showed that the increase in the intrinsic viscosity and glass transition temperature were proportional to the increase in molecular weight of polyacrylamide. On the other hand it can be seen an increase in molecular weight caused a decrease of weight loss %.