Strong, tough and bio-degradable polymer-based 3D-ink for fused filament fabrication (FFF) using WS2 nanotubes

Hila Shalom,Vlad Brumfeld,Noa Lachman,Sergey Kapishnikov,Reshef Tenne,Naum Naveh

doi:10.1038/s41598-020-65861-w

Abstract

WS2 inorganic nanotubes (WS2-NT) have been incorporated into Polylactic Acid (PLA) by melt mixing to create a bio-degradable, mechanically reinforced nanocomposite filament. The filament was then processed by Fused Filament Fabrication (FFF) 3D-printer, and the morphology and characteristics before and after printing were compared. We found that addition of WS2-NT to PLA by extrusion mixing increases the elastic modulus, yield strength and strain-at-failure by 20%, 23% and 35%, respectively. Moreover, we found that the printing process itself improves the dispersion of WS2-NT within the PLA filament, and does not require changing of the printing parameters compared to pure PLA. The results demonstrate the advantage of WS2-NT as reinforcement specifically in 3D-printable polymers, over more traditional nano-reinforcements such as graphene and carbon nanotubes. WS2-NT based 3D-printable nanocomposites can be used for variety of applications from custom-made biodegradable scaffold of soft implants such as cartilage-based organs and biodegradable soft stents to the more general easy-to-apply nano-reinforced polymers.

Highlights

WS2 inorganic nanotubes (WS2-NT) have been incorporated into Polylactic Acid (PLA) by melt mixing to create a bio-degradable, mechanically reinforced nanocomposite filament
Comparing the PLA/ WS2-NT pre- and post-printing suggest that one of the main advantages in using Fused Filament Fabrication (FFF) for nanocomposites processing is the improved dispersion of nanoparticles without the need for solvent-supported dispersion
For the first time, the dispersion of WS2-NT in PLA thermoplastic via melt extrusion, followed by FFF printing

Summary

Introduction

WS2 inorganic nanotubes (WS2-NT) have been incorporated into Polylactic Acid (PLA) by melt mixing to create a bio-degradable, mechanically reinforced nanocomposite filament. Especially 3D printing, has attracted a lot of attention in the last decades, mostly due to its high versatility in materials and designs – including topographies that cannot be produced in traditional subtractive manufacturing, and the ease of custom-tailoring products. The latter has enormous advantage in the medical fields – especially orthopedic, dental and plastic medicine, as it allows precise anatomical design of the printed device – be it an implant, a surgical tool or a support model – to the specific patient[1,2]. With a Young’s modulus of 160 GPa, bending modulus of 217 GPa, tensile strength between 16–20 GPa and strain at failure larger than 10%10,11, WS2-NT are a non-toxic alternative to Carbon Nanotubes (CNT)[12,13]

Methods

Results

Conclusion