Study on a Novel Cross-Linked Polymer Gel Strengthened with Silica Nanoparticles

Abstract

This paper studied the strengthening effects of silica nanoparticles on the polyacrylamide (PAM)/hydroquinone (HQ)–hexamethylenetetramine (HMTA) composite gel. Pure PAM/HQ–HMTA gel and PAM/HQ–HMTA gels containing silica nanoparticles up to 0.3 wt % were prepared at 110 °C. Influences of silica nanoparticles on gelation performances were systematically evaluated. By the addition of silica nanoparticles, the gelation time became shorter and the gel strength was improved observably. Rheological measurements showed that silica nanoparticles enhanced both elasticity and viscosity of the gel significantly. Thermal stability of the gel was studied by differential scanning calorimetry (DSC) measurements. The maximum tolerated temperature of the gel was improved from 137.8 to 155.5 °C by the addition of silica nanoparticles with a concentration of 0.3 wt %. Furthermore, to study the strengthening mechanisms of silica nanoparticles to the gel, the microstructure and existing state of water within the gel were inves...