Polyhydroxyalkanoate/seashell powder biocomposites with degradability and 3D printing applications.

To alleviate environmental pollution and energy crisis, the development of biopolymers with degradability is highly desirable. Polyhydroxyalkanoates (PHA) are produced and accumulated in bacteria cells, possessing good mechanical properties and the features of biodegradability and biocompatibility, becoming a promising substitute of petroleum-based polymers. In this work, seashell powders (SP) are adopted as a renewable biofiller to blend with PHA to obtain the PHA/SP biocomposites. It is found that the seashell powders are uniformly distributed in PHA matrix. Although 10 wt% seashell powder content increases the crystallinity of these biocomposites, their thermal transition temperatures and thermal stability decrease with seashell powder contents. Also, the tensile strength and elongation at break values decrease with seashell powder contents, while the elastic modulus of these biocomposites increase to 3104 MPa due to the enhanced rigidity of filler effect. Of note, these PHA/SP biocomposites can degrade under alkaline conditions within six days, and more seashell powder content facilitates the degradation process. Additionally, they can be used in 3D printing applications to fabricate various items via fused deposition modelling (FDM) technique. Therefore, this work develops a PHA/SP biocomposite system with good mechanical properties and degradability, and they are potential for 3D printing applications to serve diverse fields by fabricating customized items.