Bio-based resin/cellulose composites for UV-assisted 3D printed orthopedic casts

Abstract

An orthopedic cast is a device used for stabilizing bone fracture. To date, the conventional plaster casts do not have reasonable control over the functional characteristics of comfort, lightweight, and return in patients’ everyday life during the healing process. Three-dimensional (3D) printing is a rapidly growing and impressive technology with plentiful possibilities for customized rehabilitation tools, particularly the orthopedic cast. However, the 3D-printing materials are still limited, especially in terms of their printability and mechanical strength. In this work, bio-based resin/cellulose composites are developed as alternative materials to enhance mechanical performance for DLP (Digital Light Processing) 3D printing, which could further potentially fabricate 3D-printed cast. Triacetin, polypropylene glycol (PPG) and PEGDA are used to improve the distribution and dispersion of cellulose in bio-based resin. The results indicated that the mechanical properties improved with appropriate printed direction. The 90° printing direction gave the higher flexural strength than that of the 46.62° printing direction, which are 2650 MPa and 2487 MPa, respectively. Also, more printing accuracy was found for the 90° printing direction. SEM images revealed well dispersion of cellulose in bio-based PLA resin composite with PEGDA. However, the interfacial adhesion needs to be further improved to enhance the mechanical performance.