scholarly journals Architected poly(lactic acid)/poly(ε-caprolactone)/halloysite nanotube composite scaffolds enabled by 3D printing for biomedical applications

2021 ◽  
Author(s):  
Fahad Alam ◽  
Pawan Verma ◽  
Walaa Mohammad ◽  
Jeremy Teo ◽  
K. M. Varadarajan ◽  
...  
Keyword(s):  
Xrd Analysis ◽  
Halloysite Nanotubes ◽  
Biological Characteristics ◽  
Poly Lactic Acid ◽  
Biodegradation Rate ◽  
Fused Filament Fabrication ◽  
Composite Scaffolds ◽  
Uniform Dispersion ◽  
3D Printed ◽  
Nanocomposite Scaffolds

AbstractHerein, we report the physicochemical, thermal, mechanical and biological characteristics, including bioactivity, biodegradation and cytocompatibility of additive manufacturing-enabled novel nanocomposite scaffolds. The scaffolds comprise a blend of polylactic acid (PLA) and poly-ε-caprolactone (PCL) reinforced with halloysite nanotubes (HNTs). The nanoengineered filaments were developed by melt blending, and the nanocomposite scaffolds were manufactured by fused filament fabrication. Uniform dispersion of HNTs in the PLA/PCL blend is revealed via scanning electron microscopy. Mechanical property loss due to the addition of PCL to realize a suitable biodegradation rate of PLA was fully recovered by the addition of HNTs. Bioactivity, as revealed by the fraction of apatite growth quantified from XRD analysis, was 5.4, 6.3, 6.8 and 7.1% for PLA, 3, 5 and 7 wt% HNT in PLA/PCL blend, respectively, evidencing enhancement in the bioactivity. The degradation rate, in terms of weight loss, was reduced from 4.6% (PLA) to 1.3% (PLA/PCL) upon addition of PCL, which gradually increased to 4.4% by the addition of HNTs (at 7 wt% HNT). The results suggest that the biodegradation rate, mechanical properties and biological characteristics, including cytocompatibility and cell adhesion, of the 3D printed, microarchitected PLA/PCL/HNT composite scaffolds can be tuned by an appropriate combination of HNT and PCL content in the PLA matrix, demonstrating their promise for bone replacement and regeneration applications. Graphical abstract

scholarly journals Altering the Elastic Properties of 3D Printed Poly-Lactic Acid (PLA) Parts by Compressive Cyclic Loading

Materials ◽  
2020 ◽  
Vol 13 (19) ◽  
pp. 4456
Author(s):  
Tomaž Pepelnjak ◽  
Ako Karimi ◽  
Andraž Maček ◽  
Nikolaj Mole
Keyword(s):  
Lactic Acid ◽  
Cyclic Loading ◽  
High Performance ◽  
Compressive Loading ◽  
Elastic Behavior ◽  
Poly Lactic Acid ◽  
Fused Filament Fabrication ◽  
3D Printed ◽  
Elastic And Plastic Deformation ◽  
Cylindrical Samples

In designing high-performance, lightweight components, cellular structures are one of the approaches to be considered. The present study aimed to analyze the effect of the infill line distance of 3D printed circular samples on their compressive elastic behavior. Lightweight cellular poly-lactic acid (PLA) samples with a triangular infill pattern were exposed to cyclic compressive loading and their stiffness was investigated. PLA is one of the most commonly used thermoplastic materials in additive manufacturing using the fused filament fabrication (FFF) process. Cylindrical samples with a diameter of 11.42 mm and a height of 10 mm were printed using FFF technology with two different infill line distances (1.6 mm and 2.4 mm). Comparing the nominal compressive stress-nominal strain curves under cyclic loading showed that the first cycle response was significantly different with respect to the subsequent ones. Furthermore, an analysis of the dependence of the modulus of elasticity on the effects of cyclic loading was performed. It was found that through elastic deformation, and combined elastic and plastic deformation, the samples’ properties such as stiffness could be altered.

scholarly journals Poly(Lactic) Acid Reinforced with Alkaline Lignin Biocomposites Prepared by Thermal Extrusion for Sustainable 3D Printing Process

2021 ◽  
Vol 2129 (1) ◽  
pp. 012003
Author(s):  
Nurul Amirah Abd Rahman ◽  
Hazleen Anuar ◽  
Fathilah Ali ◽  
Jonghwan Suhr
Keyword(s):  
Mechanical Properties ◽  
Lactic Acid ◽  
3D Printing ◽  
Natural Fiber ◽  
Tensile Tests ◽  
Poly Lactic Acid ◽  
Fused Filament Fabrication ◽  
3D Printed ◽  
Functional Components ◽  
Thermal Extrusion

Abstract The focus of this work is the mechanical characterization of biomaterials produced by 3D printing based on fused filament fabrication (FFF) process that has been mainly used for prototype rather than functional components due to the limited mechanical properties of pure thermoplastics parts. Addition of reinforcements from natural fiber has been adopted to improve the mechanical properties of the 3D printed parts. In this study, alkaline lignin powder that has been extracted from oil palm empty fruit bunches (OPEFB) via alkaline extraction process were used as filler in the production of biocomposites with poly(lactic) acid (PLA). Poly(lactic) acid filaments filled with 1% of alkaline lignin powder and has been compared with the presence of 5% of epoxidized palm oil (EPO) by means of thermal extrusion and further proceed with 3D printing. The samples were mechanically characterized using tensile tests and the fractography were observed. Tensile test that has been done on the filaments reveal that the filament with addition of lignin and EPO shows improved mechanical properties with higher tensile strength as well as lower stiffness. The 3D printed samples of the filament compositions also exhibit similar trend where the said filament has the best mechanical properties when the EPO is incorporated in the filament.

scholarly journals Deterioration of the Mechanical Properties of FFF 3D-Printed PLA Structures

Inventions ◽  
2020 ◽  
Vol 6 (1) ◽  
pp. 1
Author(s):  
Asahi Yonezawa ◽  
Akira Yamada
Keyword(s):  
Mechanical Properties ◽  
3D Printing ◽  
Test Piece ◽  
Tensile Tests ◽  
Poly Lactic Acid ◽  
Uniaxial Tensile ◽  
Layer By Layer ◽  
Fused Filament Fabrication ◽  
Test Pieces ◽  
3D Printed

Poly(lactic acid) (PLA) is a biodegradable polymer material used for the fabrication of objects by fused filament fabrication (FFF) 3D printing. FFF 3D printing technology has been quickly spreading over the past few years. An FFF-3D-printed object is formed from melted polymer extruded from a nozzle layer-by-layer. The mechanical properties of the object, and the changes in those properties as the object degrades, differ from the properties and changes observed in bulk objects. In this study we evaluated FFF-3D-printed objects by uniaxial tensile tests and four-point flexural tests to characterize the changes of three mechanical properties, namely, the maximum stress, elastic modulus, and breaking energy. Eight types of test pieces printed directly by an FFF 3D printer using two scan patterns and two interior fill percentages (IFPs) were tested by the aforesaid methods. The test pieces were immersed in saline and kept in an incubator at 37 °C for 30, 60, or 90 days before the mechanical testing. The changes in the mechanical properties differed largely between the test piece types. In some of the test pieces, transient increases in strength were observed before the immersion degraded the strength. Several of the test piece types were found to have superior specific strength in the tests. The results obtained in this research will be helpful for the design of PLA structures fabricated by FFF 3D printing.

scholarly journals Antioxidant PLA Composites Containing Lignin for 3D Printing Applications: A Potential Material for Healthcare Applications

Pharmaceutics ◽  
2019 ◽  
Vol 11 (4) ◽  
pp. 165 ◽  
Author(s):  
Juan Domínguez-Robles ◽  
Niamh Martin ◽  
Mun Fong ◽  
Sarah Stewart ◽  
Nicola Irwin ◽  
...  
Keyword(s):  
Wound Care ◽  
Radical Scavenging Activity ◽  
Radical Scavenging ◽  
Poly Lactic Acid ◽  
Fused Filament Fabrication ◽  
Healthcare Applications ◽  
Dpph Method ◽  
3D Printed ◽  
Wound Healing Model ◽  
Printed Materials

Lignin (LIG) is a natural biopolymer with well-known antioxidant capabilities. Accordingly, in the present work, a method to combine LIG with poly(lactic acid) (PLA) for fused filament fabrication applications (FFF) is proposed. For this purpose, PLA pellets were successfully coated with LIG powder and a biocompatible oil (castor oil). The resulting pellets were placed into an extruder at 200 °C. The resulting PLA filaments contained LIG loadings ranging from 0% to 3% (w/w). The obtained filaments were successfully used for FFF applications. The LIG content affected the mechanical and surface properties of the overall material. The inclusion of LIG yielded materials with lower resistance to fracture and higher wettabilities. Moreover, the resulting 3D printed materials showed antioxidant capabilities. By using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) method, the materials were capable of reducing the concentration of this compound up to ca. 80% in 5 h. This radical scavenging activity could be potentially beneficial for healthcare applications, especially for wound care. Accordingly, PLA/LIG were used to design meshes with different designs for wound dressing purposes. A wound healing model compound, curcumin (CUR), was applied in the surface of the mesh and its diffusion was studied. It was observed that the dimensions of the meshes affected the permeation rate of CUR. Accordingly, the design of the mesh could be modified according to the patient’s needs.

scholarly journals Influence of Internal Innovative Architecture on the Mechanical Properties of 3D Polymer Printed Parts

Polymers ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 1129 ◽  
Author(s):  
Mihai Alin Pop ◽  
Cătălin Croitoru ◽  
Tibor Bedo ◽  
Virgil Geamăn ◽  
Irinel Radomir ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Lactic Acid ◽  
Wood Flour ◽  
Poly Lactic Acid ◽  
Fused Filament Fabrication ◽  
Strength Performance ◽  
Simple Support ◽  
3D Printed ◽  
Internal Architecture

The utilization of polymer-based materials is quickly expanding. The enterprises of today are progressively seeking techniques to supplant metal parts with polymer-based materials as a result of their light weight, simple support and modest costs. The ceaselessly developing requirement for composite materials with new or enhanced properties brings about the preparation of different polymer mixes with various arrangements, morphologies and properties. Fused filament fabrication processes such as 3D-printing are nowadays shaping the actual pathway to a full pallet of materials, from art–craft to biomaterials. In this study, the structural and mechanical behavior of three types of commercially available filaments comprised of synthetic poly(acrylonitrile-co-butadiene-co-styrene) (ABS), poly(lactic acid) (PLA) and poly(lactic acid)/polyhydroxyalkanoate reinforced with bamboo wood flour composite (PLA/PHA BambooFill) were assessed through mechanical testing and optical microscopy, aiming to understand how the modifications that occur in the printed models with internal architecture are influencing the mechanical properties of the 3D-printed material. It has been determined that the material printed from PLA presents the highest compression strength, three-point bending and shock resistance, while the ABS shows the best tensile strength performance. A probability plot was used to verify the normality hypothesis of data for the tensile strength, in conjunction with the Anderson–Darling statistic test. The results of the statistic indicated that the data were normally distributed and that there is a marked influence of the internal architecture of the 3D-printed models on the mechanical properties of the printed material.

scholarly journals Preparation of Porous Poly(Lactic Acid)/Tricalcium Phosphate Composite Scaffolds for Tissue Engineering

2021 ◽  
Vol 12 (4) ◽  
pp. 5610-5624
Keyword(s):  
Tissue Engineering ◽  
Tricalcium Phosphate ◽  
Glass Ceramics ◽  
Chloroform Solution ◽  
Xrd Analysis ◽  
Poly Lactic Acid ◽  
Absorption Bands ◽  
Composite Scaffolds ◽  
Resorbable Polymers ◽  
Composite Foams

The development of bioactive and composite materials for tissue engineering applications is being investigated worldwide. Many approaches have been published by including combinations of resorbable polymers with hydroxyapatite (HA), tricalcium phosphate (TCP), bioactive glasses and glass-ceramics in different scaffolds architectures. Taking into account these antecedents, porous polylactic acid (PLA)/TCP composites were fabricated by employing dissolution-leaching technic from PLA/chloroform solution (10, 15, and 20 wt % of TCP). Composite scaffolds exhibited porosity values 1.3 times higher when compared to PLA foams. Their bioactive response of the composite foams after immersion in a simulated body fluid (SBF) was studied by X-Ray Diffraction (XRD) and Fourier Transform Infrared Spectroscopy (FTIR-ATR). By XRD analysis, diffraction peaks attributed to hydroxyapatite deposition were observed; and by FTIR-ATR, new absorption bands corresponding to HA were detected. Regarding mechanical properties, an increasing tendency on elastic Young's modulus values was observed at higher TCP concentrations. These results envision the feasibility of using these composites as precursors for bone tissue materials engineering.

scholarly journals Surface modification of fused filament fabrication (FFF) 3D printed substrates by inkjet printing polyimide for printed electronics

2020 ◽  
Vol 36 ◽  
pp. 101544
Author(s):  
Devin J. Roach ◽  
Christopher Roberts ◽  
Janet Wong ◽  
Xiao Kuang ◽  
Joshua Kovitz ◽  
...  
Keyword(s):  
Surface Modification ◽  
Inkjet Printing ◽  
Printed Electronics ◽  
Fused Filament Fabrication ◽  
3D Printed

scholarly journals Evaluation of the Circularity of Recycled PLA Filaments for 3D Printers

2020 ◽  
Vol 10 (24) ◽  
pp. 8967
Author(s):  
Victor Gil Muñoz ◽  
Luisa M. Muneta ◽  
Ruth Carrasco-Gallego ◽  
Juan de Juanes Marquez ◽  
David Hidalgo-Carvajal
Keyword(s):  
Circular Economy ◽  
Protective Equipment ◽  
Fused Filament Fabrication ◽  
Circular Loop ◽  
Material Supply ◽  
3D Printers ◽  
3D Printed ◽  
Circular Economics ◽  
High Level ◽  
Additional Value

The circular economy model offers great opportunities to companies, as it not only allows them to capture additional value from their products and materials, but also reduce the fluctuations of price-related risks and material supply. These risks are present in all kind of businesses not based on the circular economy. The circular economy also enables economic growth without the need for more resources. This is because each unit has a higher value as a result of recycling and reuse of products and materials after use. Following this circular economics framework, the Polytechnic University of Madrid (Universidad Politécnica de Madrid, UPM) has adopted strategies aimed at improving the circularity of products. In particular, this article provides the result of obtaining recycled PLA filament from waste originating from university 3D FFF (fused filament fabrication) printers and waste generated by “Coronamakers” in the production of visors and parts for PPEs (Personal Protective Equipment) during the lockdown period of COVID-19 in Spain. This filament is used in the production of 3D printed parts that university students use in their classes, so the circular loop is closed. The obtained score of Material Circularity Indicator (MCI) of this material has been calculated, indicating its high level of circularity.

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