Adhesives prepared from recycled polyol had shorter
gel time and greater dry bonding strength than those of adhesives prepared from a commercial polyol.
From the rheology measurements the
gel time was determined and found to decrease with increasing initiator concentration.
The
gel time of aliphatic coatings allowed this technique to be used; however, the aromatic systems used as controls could not be applied this way due to their extremely fast set times.
To measure the
gel time of the different lignin phenolic resins, a Sunshine 22A
gel time meter was used.
Increases in accelerator concentration decreases the
gel time significantly.
In some reports, the
gel time has been determined as the time when the viscosity of the reacting system tends to infinity [21].
This is consistent with the
gel time data in Figure 8.
Gel time was measured with a temperature-controlled hot plate by standard knife method.
At the same F/U molar ratio, free formaldehyde content and
gel time of the resins decreased as melamine content increased.
With a
gel time of 47 minutes in DGEBA standard liquid epoxy resin, XTA-801 can be used alone or blended with other epoxy curing agents e.
Organometallic promoters for polyesters include Copac cobalt/potassium complex, which can extend more costly cobalt promoters and reduce color; Nuxtra cobalt-12%, a standard cobalt promoter; and Nuodex cobalt 254 modifier-promoter, which helps control speed of gel promotion and prevents
gel time drift.
Your inspector should also verify the
gel time of the grout each time a new batch is mixed.
