Experimental and simulation studies of hybrid MWCNT/montmorillonite reinforced FDM based PLA filaments with multifunctional properties enhancement

The recent investigation in the development of novel multifunctional thermoplastic polymer-based filaments has contributed to the extensive use of hybrid nanofiller combinations. Montmorillonite (MMT) and multiwalled carbon nanotubes (MWCNT) are nanofillers with exceptional properties and their combination tends to induce synergistic property enhancement on incorporation within the polymer matrix. In our current study, CNT-MMT hybrid has been synthesized, while XRD, FTIR, Raman, and TEM confirmed its successful formation. Different wt% (0.5-2) of CNT-MMT were reinforced into polylactic acid (PLA) matrix and their inclusive properties were analyzed in order to obtain percolation threshold concentration. The tensile strength analysis of PLA with 1% CNT-MMT displayed 47.4% enhancement as compared to virgin PLA, while DMA analysis confirmed storage modulus enhancement. These results were also corroborated with simulation studies using ANSYS. However, with 2% addition of CNT-MMT, the tensile strength reduced due to nanofiller agglomeration, which was also verified with SEM studies. The thermal and electrical properties of nanocomposites also augmented considerably due to CNT-MMT reinforcement with electrical conductivity of PLA + 1% CNT-MMT enhanced by 9 orders of magnitude. These multifunctional filaments tend to produce refined 3D printed structure using FDM and could be harnessed toward advanced 3D printing applications for commercial devices.