3D-Printing Nanocellulose-Poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) Biodegradable Composites by Fused Deposition Modeling

Fabrication of new biobased composites with remarkable properties offers an attractive pathway for producing environmentally friendly materials. Here, a reinforcement for poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBH) with functionalized cellulose nanocrystals (CNCs) is presented and used to successfully 3D-print such composites by fused deposition modeling (FDM). Acetylated CNC content varies from 5 to 20 wt % in order to evaluate the effect of the reinforcing agent on thermal and mechanical properties in the composites. The reinforcing effect of CNC is investigated by dynamic mechanical, thermal, and rheological analysis. Thermogravimetric analysis and infrared spectroscopy allow one to assert the success of chemical functionalization, whereas transmission electron microscopy is used to evaluate the impact of chemical modification on the morphology of the crystals. 3D-printability of biobased composites is proved by developing structures of complex designs with a FDM printer. Finally, the degree of disintegration under composting conditions is studied. Findings from these tests serve as an important step forward toward the development of ecofriendly materials for 3D-printing complex architectures with tailored mechanical properties and functionalities.