Gelation Behavior of Polyacrylamide-Polyethyleneimine: Effects of Diethylenetriamine and Glycerol Addition

Polymer gel systems find applications in diverse areas, ranging from contact lenses to agriculture and oil production. In general, polyacrylamide (PAM) gels are produced by reaction with metallic (low temperatures) and organic (high temperatures) crosslinking agents. In this paper, given crescent environmental concerns, polyethyleneimine (PEI), an organic reactant, was chosen as the crosslinker of PAM, at 65 ºC. The effects of using a solution of water/glycerol as the solvent for preparing the gels and the addition of diethylenetriamine (DETA), a n-alkylamine, on the gelation kinetics and gel stability were evaluated. The data presented in this paper indicates that the solvent mixture provided a more controlled gelling behavior by means of delaying the gelation time. Also, diethylenetriamine acted both as an efficient anti-syneresis agent, improving gel stability, and by delaying the progress of gel’s strength.