Comparing the gelation time
of samples with a different polymer content in the base mixture, no correlation was found.
The gelation time
for the formulation was between 9mins to 11mins and initial gelation temperature of 31[degrees]C reaching to final temperature of 29[degrees]C.
From the fit, we obtain that the gelation time
is [t.sub.gel] = (30.1 [+ or -] 0.2) hours, and s = (0.62 [+ or -] 0.03), values that are very similar to those found from rotational rheometry.
The factors are concentrations of PAM and PEI, while the responses are viscosity and gelation time
. The factor column in Table 1 presents the range and combination of the independent variable runs of the CCD approach.
Table 1 shows the physicochemical characterization ([n.sub.D.sup.25], pH) of some initial mixed solution template/precursor and the value of the gelation time
of these synthesized samples.
As an important evaluation indicator for injectable hydrogel, gelation time
of the composite hydrogel was first studied in Figure 3(b).
The samples were analyzed periodically on every month, and found that there are no changes in visual appearance, clarity, and gelation time
. After 3 month pH values of S1, S2 S3 and S4 formulations were found as 7.12[+ or -]0.002, 7.18[+ or -]0.001, 7.20[+ or -]0.001 and 7.21[+ or -]0.002, respectively.
1 and corresponds to the point at which the viscosity starts to increase, whereas point B is designated as the gelation time
. In certain formulations, the cure was inhibited and this point could not be precisely determined.
Furthermore, foaming multiple of foamed gel adopted in petroleum exploitation is small and gelation time
is long, while those of foamed gel used in coal mine for fire prevention and extinguishing are high and controllable (generally 10~20 min), more difficult to investigate, and with more complex influencing factors.
The bulk gel is easily affected by shearing from ground equipment and porous media, by chromatographic separation effect, by dilution from the formation water, and by touch physical and chemical conditions (temperature, pressure, and salinity) in formation; thus, it is hard to control the gelation time
, gel strength, and the entering-formation depth of the gel when using bulk gel in a field test .
Results of functional properties of rice used for preparing masa gave foam capacity (23.7%), foam stability (88.5%), water absorption capacity (0.02%), gelation capacity (20%) and gelatinization temperature (82oC) while gelation time
was 20 minutes.
measurements were made of formulations with varying levels of Modaflow to establish the influence which the dispersing agent might have on the gelation time
. Modaflow is an ethyl acrylate-2-ethylhexyl acrylate copolymer hut also contains carboxylic acid functions which can potentially enter into the epoxy cure reaction.