How does temperature affect the mechanical strength of cross-linked polyacrylamide gel?

Thus, the mechanical strength of cross-linked polyacrylamide gel increases with the increase in temperature (Fig. 9). The elastic modulus increased gradually upon the addition of the cross-linkers until it reached a constant level indicating that the gel formation reaction is over. Table 7.

Does NPAM gel strength affect gelation time?

To study the effect of various parameters on the gelation time of the NPAM gel, a gel strength code method was conducted to determine gelation time ( Sydank and Argabright, 1987 ). The gel strength during development of gelation kinetics was expressed as an alphabetic code of A through I which is shown in Table 1.

Does Gelant solution increase the strength of a polymer?

Initially, viscosity of gelant solution was very low and gel strength was almost the same as that of polymer solution strength and when the cross-linking reaction took place in the gelant solution, it led to a three-dimensional gel polymer network and an increase in gel strength was noticed. 4. Gelation mechanism

How long does it take to gel a polymer?

Gelation time can be controlled from a few hours to several days depending upon the gel composition and environmental conditions. As the concentration of polymer in the gelant solution increased, the gelation time decreased.

How do you control NPAM gel strength?

The gelation time and gel strength of the NPAM gel can be controlled by adjusting the NAPM polymer or cross-linker concentration. The adjusted gelation time ensures that the gel system enters the in-depth formation, whereas the controllable gel strength gives the gel system enough strength to plug high permeability zones.

Does NPAM gel have long-term stability below 143 °C?

The broad flat segment below 143 °C suggests that the energy of the chemical bonds in the gel systems is strong enough to overcome the force of the intramolecular reactions, and thereby the gel systems have good stability below this temperature. It indicates that the NPAM gel can obtain long-term stability below this temperature.