Characteristic shrinkage evaluation of photocurable materials

Photocurable materials have many advantages such as rapid curing, low energy consumption and a broad variety of favorable characteristics; as a result, their application areas are currently expanding. In order to fully utilize the properties of these materials, the related “shrinkage” problem (corresponding to the specific volume reduction due to the reaction between monomer species) must be resolved first. In this study, we investigated the dependence of the linear shrinkage of a monomer in the axial direction on various internal and external factors. In addition, a complementary relationship describing the photocuring behavior of a polymer was studied by photo-differential scanning calorimetry (photo-DSC). The observed shrinkage characteristics depend on the monomer size and structure, UV radiation intensity and photoinitiator concentration. In contrast to the photo-DSC results, the monomer shrinkage parameters are related to the bulk properties of a material. Hence, the dependence of the material depth profile on external factors was evaluated.