Preparation of polylactic acid/TEMPO-oxidized bacterial cellulose nanocomposites for 3D printing via Pickering emulsion approach

The aim of this study is to produce a novel TEMPO-oxidized bacterial cellulose (TOBC) reinforced Polylactic acid (PLA), fully biodegradable composites for fused deposition molding (FDM). In order to get uniform dispersion of BC in PLA matrix, TEMPO-mediated oxidation reaction and Pickering emulsion were used. The PLA composite microspheres were found uniformly coated by TOBC, via Pickering emulsion approach. And screw extrusion was used to prepare PLA/TOBC filaments for FDM. The mechanical properties, crystallinity, fluidity and thermal stability of PLA/TOBC nanocomposites were systematically investigated. It was found that the addition of a small amount of TOBC could effectively improve the mechanical properties and crystal properties of PLA. Uniform dispersion of TOBC in PLA matrix is helpful for forming a three-dimensional network and cross-linking structure which acts as a nucleating agent to promote the crystallization of PLA. In this paper, the mechanical properties and crystallization properties of the composites were optimized when TOBC content up to 1.5 wt%, and with further increasing TOBC, TOBC accumulates were found in PLA matrix, which were defects for PLA composites, the mechanical properties and crystallinity of the nanocomposites were reduced.