Cure Shrinkage Characterization of an Epoxy Resin System by Two in Situ Measurement Methods

Dimensional accuracy of composites manufacturing is a major issue for part producers, especially when tight tolerances are required. One of the main causes of dimensional variations is the resin volumetric changes during the cure. In this article, volumetric cure shrinkage of a one part epoxy system was characterized using two different methods. First, a modified rheology method was used to measure the volumetric cure shrinkage after the gel point. Second, a gravimetric method measured the shrinkage over the entire cure. A linear relationship between the volumetric cure shrinkage and the degree-of-cure was deduced from the results and the resin cure kinetic models. Results show a good agreement between the two techniques. POLYM. COMPOS., 31:1603-1610, 2010. (C) 2009 Society of Plastics Engineers