Surface Etching of 3D Printed Poly(lactic acid) with NaOH: A Systematic Approach.

Matthias Schneider,Ilko Bald,Szczepan Zapotoczny,Nora Fritzsche,Andrzej Baliś,Andreas Taubert,Amr Mostafa,Agnieszka Puciul-Malinowska

doi:10.3390/polym12081711

Abstract

The article describes a systematic investigation of the effects of an aqueous NaOH treatment of 3D printed poly(lactic acid) (PLA) scaffolds for surface activation. The PLA surface undergoes several morphology changes and after an initial surface roughening, the surface becomes smoother again before the material dissolves. Erosion rates and surface morphologies can be controlled by the treatment. At the same time, the bulk mechanical properties of the treated materials remain unaltered. This indicates that NaOH treatment of 3D printed PLA scaffolds is a simple, yet viable strategy for surface activation without compromising the mechanical stability of PLA scaffolds.

Highlights

We have developed an automated process for the co-deposition of a stable hydrogel/calcium phosphate hybrid layer that strongly attaches to a 3D printed poly(lactic acid) (PLA) scaffold [25]
The 3D printed PLA scaffolds were treated with different NaOH solutions for different times and the properties of the treated samples are compared to the untreated starting materials
The current study provides the most complete dataset on NaOH treatment of 3D printed PLA scaffolds so far

Summary

Introduction

Poly(lactic acid) (PLA) is an interesting and highly popular bio- and biodegradable material [1,2].PLA is accessible on a large scale and its properties can be adjusted by proper choice of the (co)monomers and polymerization conditions yielding polymers with different mechanical properties and degradation profiles [3,4,5].The advent of 3D printing has brought further interest to PLA because PLA can be printed using simple and low cost approaches such as fused deposition modelling (FDM) [6,7]. 3D printing is interesting for the general area of biomaterials development because, in principle, it may be possible to provide patient-specific implants on-site and on-demand [2]. PLA offers a broad spectrum of properties (molecular weight and weight distribution, stereochemistry, comonomers) that can be adjusted rather during polymerization or after synthesis via blending, physical, or chemical modification. This must be done before filament production and requires additional equipment and laboratory steps [1,2,3,4,12,13]. Surface treatment of a printed object enables the use of commercially available PLA filaments from the printer manufacturer This filament is optimized in shape (precisely manufactured round filament) and matches the technical requirements of the printer

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Discussion

Conclusion