Depth of cure effects on structure-property relationships of 3d printed polymer materials using stereolithography

Abstract

One feature of SLA that has generally been overlooked in the literature is the effect of UV penetration depth on print layer formation. In the past, depth of cure has been studied in photopolymer coatings and adhesives, and especially thoroughly in restorative dental materials. These studies have found a presence of a network crosslinking gradient throughout the sample depth due to UV light attenuation and other factors that may affect the integrity of the resulting polymer network. However, information on depth of cure in the context of SLA 3D printing remains limited in the literature. Due to the layer-by-layer nature of the SLA print process, studying the depth of UV penetration, corresponding photopolymerization kinetics, and their effects on the polymer network’s bulk mechanical properties presents not only an opportunity to better understand the structure-property relationships of SLA 3D printed objects, but also to induce desired mechanical, thermomechanical, structural, and morphological properties for specific applications.