Preparation of 3D printable micro/nanocellulose-polylactic acid (MNC/PLA) composite wire rods with high MNC constitution

A method for the preparation of 3D printing wire rods of a micro/nanocellulose-polylactic acid (MNC/PLA) composite with up to 30% MNC constitution was developed. The micro/nanocellulose (MNC) obtained through a simple mechanical treatment of polyols swelled bleached softwood pulp possessed a mixture of micro-cellulose fibers (width was less than 2 μm) and nanocellulose fibers (width was at nanoscale). The results showed that the interfacial compatibility of MNC and PLA was improved by adding silane coupling agent (KH-550). The composition of MNC with PLA greatly decreased the melt flow rate, nevertheless, the addition of PEG increased the rate to some degree (0.568 g/10 min) to meet the printable demands for 3D printing with a FDM printer with a decomposition temperature of 250 °C–400 °C. The optimum ratio for the preparation of MNC/PLA composites for 3D printing was determined to be as follows: 30 wt% MNC modified with KH550, 5 wt% PEG6000, and 65 wt% PLA. At the optimum condition, the mechanical property of 3D products from MNC/PLA composites was maintained at a comparable level to that of neat PLA with elongation at break of 12%, tensile strength of 59.7 MPa and flexural strength of 50.7 MPa.