VINYL-ESTER AND UNSATURATED POLYESTER RESINS IN CONTACT WITH DIFFERENT CHEMICALS - DYNAMIC-MECHANICAL BEHAVIOR

A prior study has shown for a vinyl ester resin that the adequate choi ce of the curing conditions becomes completely necessary to reach the maximum glass transition temperature. In the same study, the Variation s produced in the dynamic mechanical properties because of exposure to different solvents were related to the chemical structure of both the resin and solvent. This investigation was undertaken in an attempt to analyze the effects of solvent exposure on the viscoelastic propertie s of resins currently used for applications in which the resin is kept in contact with the solvents. Several vinyl ester resins as well as v arious unsaturated polyester resins immersed in different liquids were investigated. The influence of exposure time to the solvent as well a s that for the temperature were characterized using dynamic mechanical analysis. The chemical structure of the resin was found to be determi nant in the changes produced after solvent exposure. (C) 1999 John Wil ey & Sons, Inc.