Analysis of the crosslinking process of a phenolic resin by thermal scanning rheometry

Abstract The curing reaction of a phenolic resin (resole type) carried out in the absence of an initiator was studied by thermal scanning rheometry under isothermal conditions at temperatures from 70 to 105°C. The same curing reaction was studied in the presence of an acid as a catalyst in the temperature range of 50–80°C. The gel time, which was defined by several criteria, was found to be a good parameter to determine the apparent activation energy of this process. An empirical model was used to predict the change in complex viscosity with time until the gel time was reached. If first‐order kinetics were assumed, the apparent kinetic constant of the curing reaction could be obtained. Furthermore, the effect that the addition of water and free phenol had on the curing process of this type of resin was studied. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 57–65, 2002