Physicochemical Characterization and Finite Element Analysis-Assisted Mechanical Behavior of Polylactic Acid-Montmorillonite 3D Printed Nanocomposites

Abstract

This work aims to improve the properties of poly(lactic acid) (PLA) for future biomedical applications by investigating the effect of montmorillonite (MMT) nanoclay on physicochemical and mechanical behavior. PLA nanocomposite filaments were fabricated using different amounts of MMT (1.0, 2.0, and 4.0 wt.%) and 2 wt.% Joncryl chain extenders. The 3D-printed specimens were manufactured using Fused Filament Fabrication (FFF). The composites were characterized by Gel Permeation Chromatography (GPC), Melt Flow Index (MFI), X-ray Diffraction (XRD), and Fourier-transform infrared spectroscopy (FTIR). The thermal properties were studied by means of Differential Scanning Calorimetry (DSC) and Thermogravimetric Analysis (TGA). Moreover, the hydrophilicity of the PLA/MMT nanocomposites was investigated by measuring the water contact angle. The mechanical behavior of the PLA/MMT nanocomposites was examined with nanoindentation, compression tests, and Dynamic Mechanical Analysis (DMA). The presence of Joncryl, as well as the pretreatment of MMT before filament fabrication, improved the MMT distribution in the nanocomposites. Furthermore, MMT enhanced the printability of PLA and improved the hydrophilicity of its surface. In addition, the results of nanoindentation testing coupled with Finite Element Analysis showed that as the MMT weight fraction increased, as well as an increased Young’s modulus. According to the results of the mechanical analysis, the best mechanical behavior was achieved for PLA nanocomposite with 4 wt.% MMT.

Blending PLA with Polyesters Based on 2,5-Furan Dicarboxylic Acid: Evaluation of Physicochemical and Nanomechanical Properties

“…A diamond triangular tip Berkovich indenter (angle of 65°, tip radius is 100 nm) was used and three points were selected and measured using an optical microscope integrated into the device. The modulus and hardness were determined based on the method of Oliver and Pharr [ 25 ] and previous work [ 26 , 27 , 28 , 29 , 30 ]. The maximum load was 10 mN and was achieved at a rate of 1.66 mN/s.…”

Graphene Nanoplatelets’ Effect on the Crystallization, Glass Transition, and Nanomechanical Behavior of Poly(ethylene 2,5-furandicarboxylate) Nanocomposites

“…The indentation depth was recorded as a function of load and the maximum load was applied to the nanoindenter during the creep time. In this study, the basic mechanical properties that were determined were the hardness and elastic modulus of the amorphous and semicrystalline neat PEF and their PEF/GNP nanocomposite samples using the Oliver and Pharr method and previous work [ 59 , 60 , 61 , 62 , 63 , 64 , 65 ]. The average value of ten measurements taken at different locations was used to calculate these properties.…”

3D printed poly(lactic acid)-based nanocomposite scaffolds with bioactive coatings for tissue engineering applications

“…The PLA/MMT nanocomposite filament was fabricated using PLA with 2 wt.% Joncryl and 4 wt.%MMT according to our previous work [36]. The addition of 4 wt.% MMT improves the printability of PLA filaments and the surface quality of 3D printed specimens, as well as the mechanical behavior at compression testing [36]. PLA/MMT nanocomposite filament was produced using FFF technology.…”

“…The nanomechanical properties of PLA/MMT/SrBG and PLA/MMT/SrBG/nHA were investigated using the nanoindentation technique and were compared to PLA and PLA/MMT4 without coating according to our previous research [36]. A dynamic ultramicrohardness tester DUH-211 (Shimadzu Co., Kyoto, Japan) using a 100-nm-radius triangular pyramid indenter tip (Berkovich-type indenter) was used to determine the mechanical performance of PLA/ MMT4 nanocomposites with two types of coating.…”

“…To improve the mechanical properties of the scaffold, montmorillonite (MMT), a 2D nanophyllosilicate clay, was added during filament preparation in PLA. In our previous work, it was found that the optimum content of MMT was 4 wt.% [36]. MMT is much cheaper than bioceramics and readily available.…”