Thermal Post-Processing of 3D-Printed Poly(glycerol dodecanedioate) Controls Mechanics and Shape Memory Properties

In the clinic, patients largely prefer treatment via minimally invasive procedures (MIS). This patient preference has led to increased interest in the use of shape memory polymers (SMP) for the development of medical devices that can be delivered via MIS. Acrylated poly(glycerol-dodecanedioate) (APGD) is a biodegradable SMP that shows promise for use in MIS procedures. APGD can be 3D printed using both material extrusion (ME) and vat photopolymerization (VP) printing modalities; however, differences were measured between APGD samples’ physical, mechanical, and shape memory properties. This work looks to characterize the effects of thermal post-processing on 3D printed APGD and to determine whether thermal post-processing is able to reduce these differences in APGD properties due to manufacture modality. Differences in melt transition (Tm), relative crystallinity, gel content, shape recovery (Rr), and the Neo-Hookean nonlinear elastic C1 parameter amongst freshly fabricated unprocessed samples are reduced after 24 h of thermal post-processing. Taken together, 3D printing allows for the development and rapid prototyping of biocompatible resins, controlled manufacture of samples with complex porous geometries, improved feature resolution, and reduced cost for low volume clinical production. This study emphasizes the utility of tailoring post-processing methodologies to the manufacture process to govern the thermal, mechanical, and shape memory properties of 3D printed shape memory polymers for biomedical applications.