Incorporation of graphitic nano-filler and poly(lactic acid) in fused deposition modeling

This article presents research results showing that the property of fused deposition modeling (FDM) products is obtained jointly by careful control of processing parameters, structure of products, and the composition of material. In this manuscript, poly(lactic acid) (PLA) was incorporated with graphene or carbon nanotube (CNT) through repeated melt blending. Filament of the PLA/graphitic nano-filler was prepared and used in FDM. Rheological and thermal analysis were conducted to assess the suitability of the composite as FDM feedstock, and mechanical and electrical property were tested subsequently. Research results demonstrate that filament diameter-regarded as processing-related parameter-was positively correlated with mechanical stiffness and strength of FDM products. Tensile elongation at break of FDM products exhibited significant increase at a raster angle of 45 degrees compared with the filament before FDM, showing in certain cases, material property depends more on the structure than the composition. And when incorporated with graphene or CNT, the electrical conductivity of the PLA-based composite increased drastically. The electrical conductivity of the best experiment sample reached similar to 10(-1) Sm-1, demonstrating that composition is the key to functionalizing material. (C) 2017 Wiley Periodicals, Inc.