Effects of post-curing conditions on mechanical properties of vinyl-ester resins

摘要

In this paper, the effects of post-curing condition on mechanical properties of vinyl-ester resins are investigated by means of the dynamic viscoelastic test and the tensile test. As the post-cured time becomes longer, the behaviors of loss tangent(tanδ) curves changes from two peaks to one peak, mainly due to curing of unreacted parts of the vinyl-ester resin. In the short time region of post-cure, the value of glass transition temperature (Tg) varies steeply to the time. On the other hand, in the long time region of post-cure, the variation of glass transition temperature is constant to the post-cured time. Tensile strength and Young's modulus increased due to the post-cure as well as the increase of Tg. Moreover; from stress-strain curves, it is found that the fracture strain of post-cured specimen is larger than that of un-postcured specimen.