Shrinkage determination of a reactive polymer with volumetric dilatometry

Several methods exist to determine the matrix volumetric shrinkage due to polymerisation/curing and thermal effects. A volumetric shrinkage test method that was further developed by Li et al. [C. Li, et al., In-situ measurement of chemical shrinkage of MY750 epoxy resin by a novel gravimetric method, Composites Science and Technology 64 (1) (2004) 55-64] is based on the buoyancy principle and allows monitoring of volumetric changes during the entire cure cycle. The aim is to use this test method for validation of cure shrinkage results obtained with Fibre Bragg gratings that were presented in a previous paper [P.P. Parlevliet, H.E.N. Bersee, A. Beukers, Measurement of (post-)curing strain development with fibre Bragg gratings, Polymer Testing, 29(3) (2010) 291-301.]. For that purpose, experiments have been conducted with a thermosetting polyurethane (turane) resin system. Even although the FBG and volumetric test set-ups resulted in different curing behaviour (different peak temperatures), the final linear shrinkage values were comparable.