3D Printing of Polymers
3D printing (3DP) has rapidly become a viable manufacturing method in its own right due to the advantages offered compared with traditional machining, casting, foaming, forming, etc.; however, 3DP has been limited in many fields by the lack of suitable materials. There is a need for new photopolymer formulations that are compatible with the rapid manufacturing needs within the 3DP community while also being able to serve the biomedical community’s needs, including robust mechanical properties and minimally invasive final prototype designs, including shape memory features. Moving away from acrylate-based systems may also improve the biocompatibility of printed implants and devices, as will the development of degradable formulations. In degradable polymeric materials, polyesters offer perhaps some of the best options for 3D printing materials, due to the range of possible material properties. While multiple avenues towards polyesters are possible, ring opening polymerizations (ROP) offer a number of advantages, including tunable dispersity, molecular weight, and architecture from a broad library of possible starting monomers. An important subset of ROP is ring opening copolymerization (ROCOP), most commonly represented by the copolymerization of a cyclic anhydride and an epoxide monomer, ideally yielding a perfecting alternating copolymer polyester. Such materials have been presented as possessing interesting elastomeric behaviors with select formations, as well as shape memory behaviors under certain conditions, the ability for orthogonal functionalization, and the utilization of thiol-ene type reactions to introduce varied pendant groups. With regards to 3D printing, this is an important consideration, as photopolymerizations such as thiol-ene reactions are most likely to produce mechanically integrated components while also allowing for possible post-polymerization functionalization, as seen with poly(β-myrcene), as well as a wider range of tailorable material properties.
Polymeric Biomaterials and Their Performances
Understanding the behaviors