Synthesis and Characterization of Hydrophobically Modified Cationic Polyacrylamide with Low Concentration of Cationic Monomer

Abstract

Hydrophobically modified cationic polyacrylamides were synthesized via free radical solution copolymerization using ammonium persulphate/sodium hydrogen sulphite as the redox initiator. Epichlorohydrin, acrylamide and trialkylamine were used to synthesize the hydrophobic cationic monomer 3-acrylamido-2-hydroxypropyltriakylammonium chloride (AHPTAAC) in which the trialkyl group was trihexylamine (AHPTHAC), trioctylamine (AHPTOAC) and tridodecylamine (AHPTDAC). Low concentration (1–6 mol%) of cationic monomer from each group were copolymerized with acrylamide to obtain hydrophobically modified cationic polyacrylamide. Results show that the intrinsic viscosity and molecular weight of the copolymers decreases with the concentration of the hydrophobic cationic group, whereas charge density indicates the reverse behaviour. Fourier Transform Infrared (FTIR) and Transmission Electron Microscopy (TEM) were also carried out to elucidate the structure of the copolymer.

Keywords:

• Cationic polyacrylamide
• charge density
• molecular weight

Acknowledgements

The authors acknowledge the short-term research grant provided by Universiti Sains Malaysia that has resulted in this article.