The Effects of Chitosan Source on the Properties of 3D Printed Polymer Composites

Chitosan, or deacetylated chitin, is a linear polysaccharide composed of glucosamine and N-acetyl glucosamine units. Chitin is found in the cell walls of crustaceans, fungi, and insects, making chitosan the second most abundant natural polymer on earth. The broad availability of chitosan makes it an attractive material for applications in the textile, medical, and agricultural industries as well as for use in environmental waste remediation. Additive manufacturing, or 3D printing, is a technique that can be used to produce polymeric materials on demand, based on custom digital designs. Using a digital light projection (DLP) 3D printer, we incorporated chitosan from different sources into photoresins, considering different sources for their sustainability. We explored how the source of the chitosan (fungal vs. crustacean) can affect the mechanical properties, resin incorporation, and printability of the photoresin. The 3D printed materials were tested to compare the mechanical properties of the polymers with chitosan from different sources. Higher loadings of chitosan improved the strength of the printed materials. We show that chitosan with higher loading and higher molecular weights improved the mechanical properties. However, the source of the chitosan affected the incorporation and printability of the photoresins.