scholarly journals Mechanical, Thermal and Microstructural Characteristic of 3D Printed Polylactide Composites with Natural Fibers: Wood, Bamboo and Cork

2021 ◽  
Author(s):  
Karolina E. Mazur ◽  
Aleksandra Borucka ◽  
Paulina Kaczor ◽  
Szymon Gądek ◽  
Rafał Bogucki ◽  
...  
Keyword(s):  
Fused Deposition Modeling ◽  
Elevated Temperatures ◽  
Fiber Type ◽  
Mechanical Tests ◽  
Degree Of Crystallinity ◽  
Scanning Calorimetry ◽  
Fused Deposition ◽  
The Impact ◽  
Different Levels ◽  
Natural Fillers

AbstractIn the study, polylactide-based (PLA) composites modified with natural particles (wood, bamboo, and cork) and with different levels of infilling (100%, 80%, and 60%) obtained by fused deposition modeling were tested. The effect of fiber type, infill level and crystallization rate on the mechanical properties were investigated by using tensile, flexural, and impact tests. The materials were subjected to mechanical tests carried out at 23 and 80 °C. Differential scanning calorimetry were employed to analyze crystallization behavior of composite. Furthermore, hydrothermal degradation was performed, and its effect on the properties was analyzed. The addition of natural fillers and different levels of infilling result in a similar level of reduction in the properties. However, the addition of natural fillers resulted in a slightly lower drop than the lowered infilling rate − 40% and 50% for tensile strength, respectively. Moreover, it was found that, composites made of PLA are more sensitive to high temperatures than to water. The decrease in Young's modulus of PLA at 80 °C was 90%, while after 28 days of hydrodegradation ~ 9%. The addition of fibers reduced this decrease at elevated temperatures. Importantly, in the case of a brittle material such as PLA, the impact strength has been improved by 50% for composites with cork particles and other lignocellulosic composites remained at the same level as for resin. Generally, the thermal treatment of composites increased the degree of crystallinity of the materials, as reflected in the higher results of mechanical tests.

scholarly journals Mechanical Performance Under Various Conditions of 3D Printed Polylactide Composites With Natural Fibers

2021 ◽  
Author(s):  
Karolina E. Mazur ◽  
Aleksandra Borucka ◽  
Paulina Kaczor ◽  
Szymon Gądek ◽  
Stanislaw Kuciel
Keyword(s):  
Elevated Temperatures ◽  
Mechanical Performance ◽  
Natural Fibers ◽  
Crystallization Rate ◽  
Mechanical Tests ◽  
Hydrothermal Degradation ◽  
3D Printed ◽  
The Impact ◽  
Different Levels ◽  
Additive Methods

Abstract In the study, polylactide-based (PLA) composites modified with natural particles (wood, bamboo, and cork) and with different levels of infilling (100%, 80%, and 60%) obtained by additive methods were tested. The effect of type fiber, infill level and crystallization rate on the mechanical properties were investigated by using tensile, flexural, and impact tests. The materials were subjected to mechanical tests carried out at 23 and 80 °C. Furthermore, hydrothermal degradation was performed, and its effect on the properties was analyzed. The addition of natural fillers and different level of infilling result in a similar level of reduction in the properties. Composites made of PLA are more sensitive to high temperature than to water. The decrease in Young's modulus of PLA at 80 °C was 90%, while after 28 days of hydrodegradation ~ 9%. The addition of fibers reduced this decrease at elevated temperatures. Moreover, the impact strength has been improved by 50% for composites with cork particles and for other lignocellulosic composites remained at the same level as for resin.

scholarly journals Fused Deposition Modeling of Polyamides: Crystallization and Weld Formation

Polymers ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 2980
Author(s):  
Andrea Costanzo ◽  
Umberto Croce ◽  
Roberto Spotorno ◽  
Seif Eddine Fenni ◽  
Dario Cavallo
Keyword(s):  
3D Printing ◽  
Crystallization Kinetics ◽  
Fused Deposition Modeling ◽  
Degree Of Crystallinity ◽  
Temperature History ◽  
Weld Strength ◽  
Processing Conditions ◽  
Scanning Calorimetry ◽  
Fused Deposition ◽  
Deposition Modeling

International newspapers and experts have called 3D printing the industrial revolution of this century. Among all its available variants, the fused deposition modeling (FDM) technique is of greater interest since its application is possible using simple desktop printers. FDM is a complex process, characterized by a large number of parameters that influence the quality and final properties of the product. In particular, in the case of semicrystalline polymers, which afford better mechanical properties than amorphous ones, it is necessary to understand the crystallization kinetics as the processing conditions vary, in order to be able to develop models that allow having a better control over the process and consequently on the final properties of the material. In this work it was proposed to study the crystallization kinetics of two different polyamides used for FDM 3D printing and to link it to the microstructure and properties obtained during FDM. The kinetics are studied both in isothermal and fast cooling conditions, thanks to a home-built device which allows mimicking the quenching experienced during filament deposition. The temperature history of a single filament is then determined by mean of a micro-thermocouple and the final crystallinity of the sample printed in a variety of conditions is assessed by differential scanning calorimetry. It is found that the applied processing conditions always allowed for the achievement of the maximum crystallinity, although in one condition the polyamide mesomorphic phase possibly develops. Despite the degree of crystallinity is not a strong function of printing variables, the weld strength of adjacent layers shows remarkable variations. In particular, a decrease of its value with printing speed is observed, linked to the probable development of molecular anisotropy under the more extreme printing conditions.

scholarly journals Reinforcing polypropylene with calcium carbonate of different morphologies and polymorphs

2018 ◽  
Vol 25 (4) ◽  
pp. 745-751 ◽  
Author(s):  
Yanwei Jing ◽  
Xueying Nai ◽  
Li Dang ◽  
Donghai Zhu ◽  
Yabin Wang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Calcium Carbonate ◽  
Mechanical Tests ◽  
Degree Of Crystallinity ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Crystallization Property ◽  
Reinforced Composite ◽  
Treated Sample ◽  
The Impact

Abstract The influence of calcium carbonate (CaCO3) with different polymorphs (calcite and aragonite) and morphologies (granular and rod-like) on mechanical and crystallization properties of polypropylene (PP) was investigated. Meanwhile, these CaCO3 fillers coated with oleic acid were added in different contents to PP. The results indicate that the tensile strength, flexural strength, modulus, and crystallization property of the filler-treated samples are improved, but the impact strength decreased. The crystallinity of the composites is higher than that of neat PP. Moreover, in the rod shape filler-treated sample, in both whisker species, the mechanical properties of composites are superior to the particles filled. Differential scanning calorimetry, X-ray diffraction, and mechanical tests display that calcite whisker-reinforced composite has higher crystallization enthalpy, melting enthalpy, degree of crystallinity, and mechanical properties than aragonite whiskers and calcite particles filled composites.

scholarly journals Mechanical and Physicochemical Properties of 3D-Printed Agave Fibers/Poly(lactic) Acid Biocomposites

Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3111
Author(s):  
Valeria Figueroa-Velarde ◽  
Tania Diaz-Vidal ◽  
Erick Omar Cisneros-López ◽  
Jorge Ramón Robledo-Ortiz ◽  
Edgar J. López-Naranjo ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Fused Deposition Modeling ◽  
Charpy Impact ◽  
Density Variation ◽  
Economic Life ◽  
Poly Lactic Acid ◽  
Scanning Calorimetry ◽  
Fused Deposition ◽  
The Impact ◽  
Agave Fibers

In order to provide a second economic life to agave fibers, an important waste material from the production of tequila, filaments based on polylactic acid (PLA) were filled with agave fibers (0, 3, 5, 10 wt%), and further utilized to produce biocomposites by fused deposition modeling (FDM)-based 3D printing at two raster angles (−45°/45° and 0/90°). Differential scanning calorimetry, water uptake, density variation, morphology, and composting of the biocomposites were studied. The mechanical properties of the biocomposites (tensile, flexural, and Charpy impact properties) were determined following ASTM international norms. The addition of agave fibers to the filaments increased the crystallinity value from 23.7 to 44.1%. However, the fibers generated porous structures with a higher content of open cells and lower apparent densities than neat PLA pieces. The printing angle had a low significant effect on flexural and tensile properties, but directly affected the morphology of the printed biocomposites, positively influenced the impact strength, and slightly improved the absorption values for biocomposites printed at −45°/45°. Overall, increasing the concentrations of agave fibers had a detrimental effect on the mechanical properties of the biocomposites. The disintegration of the biocomposites under simulated composting conditions was slowed 1.6-fold with the addition of agave fibers, compared to neat PLA.

scholarly journals Influence of Controlled Cooling on Crystallinity of Poly(L-Lactic Acid) Scaffolds after Hydrolytic Degradation

Materials ◽  
2020 ◽  
Vol 13 (13) ◽  
pp. 2943
Author(s):  
Javier Vazquez-Armendariz ◽  
Raquel Tejeda-Alejandre ◽  
Aida Rodriguez-Garcia ◽  
Yadira I. Vega-Cantu ◽  
Christian Mendoza-Buenrostro ◽  
...  
Keyword(s):  
Fused Deposition Modeling ◽  
Cooling System ◽  
Thermo Gravimetric Analysis ◽  
Hydrolytic Degradation ◽  
Degree Of Crystallinity ◽  
Gravimetric Analysis ◽  
Controlled Cooling ◽  
Scanning Calorimetry ◽  
Fused Deposition ◽  
Deposition Modeling

The use of hybrid manufacturing to produce bimodal scaffolds has represented a great advancement in tissue engineering. These scaffolds provide a favorable environment in which cells can adhere and produce new tissue. However, there are several areas of opportunity to manufacture structures that provide enough strength and rigidity, while also improving chemical integrity. As an advancement in the manufacturing process of scaffolds, a cooling system was introduced in a fused deposition modeling (FDM) machine to vary the temperature on the printing bed. Two groups of polylactic acid (PLA) scaffolds were then printed at two different bed temperatures. The rate of degradation was evaluated during eight weeks in Hank’s Balanced Salt Solution (HBSS) in a controlled environment (37 °C–120 rpm) to assess crystallinity. Results showed the influence of the cooling system on the degradation rate of printed scaffolds after the immersion period. This phenomenon was attributable to the mechanism associated with alkaline hydrolysis, where a higher degree of crystallinity obtained in one group induced greater rates of mass loss. The overall crystallinity was observed, through differential scanning calorimetry (DSC), thermo gravimetric analysis (TGA), and Fourier transformed infrared spectroscopy (FTIR) analysis, to increase with time because of the erosion of some amorphous parts after immersion.

Development of three-dimensional printing filaments based on poly(lactic acid)/hydroxyapatite composites with potential for tissue engineering

2021 ◽  
pp. 002199832098856
Author(s):  
Marcela Piassi Bernardo ◽  
Bruna Cristina Rodrigues da Silva ◽  
Luiz Henrique Capparelli Mattoso
Keyword(s):  
Tissue Engineering ◽  
Lactic Acid ◽  
Fused Deposition Modeling ◽  
Three Dimensional ◽  
Poly Lactic Acid ◽  
Scanning Calorimetry ◽  
Three Dimensional Printing ◽  
Fused Deposition ◽  
Deposition Modeling ◽  
3D Printed

Injured bone tissues can be healed with scaffolds, which could be manufactured using the fused deposition modeling (FDM) strategy. Poly(lactic acid) (PLA) is one of the most biocompatible polymers suitable for FDM, while hydroxyapatite (HA) could improve the bioactivity of scaffold due to its chemical composition. Therefore, the combination of PLA/HA can create composite filaments adequate for FDM and with high osteoconductive and osteointegration potentials. In this work, we proposed a different approache to improve the potential bioactivity of 3D printed scaffolds for bone tissue engineering by increasing the HA loading (20-30%) in the PLA composite filaments. Two routes were investigated regarding the use of solvents in the filament production. To assess the suitability of the FDM-3D printing process, and the influence of the HA content on the polymer matrix, thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) and scanning electron microscopy (SEM) were performed. The HA phase content of the composite filaments agreed with the initial composite proportions. The wettability of the 3D printed scaffolds was also increased. It was shown a greener route for obtaining composite filaments that generate scaffolds with properties similar to those obtained by the solvent casting, with high HA content and great potential to be used as a bone graft.

scholarly journals Analysis of the surface quality of polycaprolactam 3D prints enriched with carbon and glass fiber

2021 ◽  
Vol 338 ◽  
pp. 01005
Author(s):  
Damian Dzienniak ◽  
Jan Pawlik
Keyword(s):  
Glass Fiber ◽  
Surface Quality ◽  
Fused Deposition Modeling ◽  
Polyamide 6 ◽  
Fiber Glass ◽  
Fused Deposition ◽  
Deposition Modeling ◽  
The Impact ◽  
The Relationship

Additive manufacturing has been gaining popularity and availability year by year, which has resulted in its dynamic development. The most common 3D printing method as of today, FDM (Fused Deposition Modeling), owing to its peculiarity, does not always guarantee producing objects with low surface roughness. The authors of the present article have taken on the analysis of the impact of FDM printing on the roughness of the filament thus processed. They also investigate the relationship between the roughness of the unprocessed filament (made of polycaprolactam, that is, polyamide 6 or PA6) with admixtures of other materials (carbon fiber, glass fiber) and the surface quality of the manufactured object. The main subject of the analysis is the side surfaces of 3D prints, as it is their quality that is usually directly dependent on many factors connected with the process of the laying of the consecutive layers. The authors check step by step whether there exists a pronounced relationship between the roughness of the original filament material and the roughness of the obtained surface.

scholarly journals Semi-Interpenetrating Polymer Networks Based on Cyanate Ester and Highly Soluble Thermoplastic Polyimide

Polymers ◽  
2019 ◽  
Vol 11 (5) ◽  
pp. 862 ◽  
Author(s):  
Jingfeng Liu ◽  
Weifeng Fan ◽  
Gewu Lu ◽  
Defeng Zhou ◽  
Zhen Wang ◽  
...  
Keyword(s):  
High Performance ◽  
Elevated Temperatures ◽  
Polymer Networks ◽  
Gelation Time ◽  
Interpenetrating Polymer Networks ◽  
Step Method ◽  
Scanning Calorimetry ◽  
Sem Images ◽  
Biphenyltetracarboxylic Dianhydride ◽  
The Impact

Thermoplastic polyimide (TPI) was synthesized via a traditional one-step method using 2,3,3′,4′-biphenyltetracarboxylic dianhydride (3,4′-BPDA), 4,4′-oxydianiline (4,4′-ODA), and 2,2′-bis(trifluoromethyl)benzidine (TFMB) as the monomers. A series of semi-interpenetrating polymer networks (semi-IPNs) were produced by dissolving TPI in bisphenol A dicyanate (BADCy), followed by curing at elevated temperatures. The curing reactions of BADCy were accelerated by TPI in the blends, reflected by lower curing temperatures and shorter gelation time determined by differential scanning calorimetry (DSC) and rheological measurements. As evidenced by scanning electron microscopy (SEM) images, phase separation occurred and continuous TPI phases were formed in semi-IPNs with a TPI content of 15% and 20%. The properties of semi-IPNs were systematically investigated according to their glass transition temperatures (Tg), thermo-oxidative stability, and dielectric and mechanical properties. The results revealed that these semi-IPNs possessed improved mechanical and dielectric properties compared with pure polycyanurate. Notably, the impact strength of semi-IPNs was 47%–320% greater than that of polycyanurate. Meanwhile, semi-IPNs maintained comparable or even slightly higher thermal resistance in comparison with polycyanurate. The favorable processability and material properties make TPI/BADCy blends promising matrix resins for high-performance composites and adhesives.

scholarly journals The Effect of Crystallinity on the Toughness of Cast Polyamide 6 Rods with Different Diameters

Polymers ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 293
Author(s):  
Miklós Odrobina ◽  
Tamás Deák ◽  
László Székely ◽  
Tamás Mankovits ◽  
Róbert Zsolt Keresztes ◽  
...  
Keyword(s):  
Impact Strength ◽  
Impact Test ◽  
Charpy Impact ◽  
Polyamide 6 ◽  
Degree Of Crystallinity ◽  
Scanning Calorimetry ◽  
Tensile Impact ◽  
Different Diameters ◽  
The Impact ◽  
The Degree Of Crystallinity

The present paper concentrates on the toughness and the degree of crystallinity of the magnesium-catalyzed polyamide 6 rods cast in different diametres, which are commonly used for gear manufacturing. Its toughness cannot be regarded as a constant feature due to the casting technology. The mechanical properties of the semi-finished products are sensitive to the manufactured dimension, e.g., cast diameter, which are investigated by the Charpy impact test and tensile impact test. It is generally accepted that the impact strength and tensile-impact strength correlate with the degree of crystallinity beside many other material’s feature. Crystallinity is evaluated by Differential Scanning Calorimetry. The aim of this study is to determine the relationship between toughness and crystallinity of the magnesium-catalyzed cast PA6 rods with different diameters. For the research cast rods between 40 and 300 mm diameter were selected in seven-dimensional steps. Based on the results, it was found that the toughness depends strongly on the diameter size. Furthermore, it is proved that the crystallinity explains 62.3% of the variation of the Charpy’s impact strengths, while the tensile impact method was not suitable to detect the difference between the test samples.

scholarly journals The impact of 3D-printed LAY-FOMM 40 and LAY-FOMM 60 on L929 cells and human oral fibroblasts

2020 ◽  
Author(s):  
Gunpreet Oberoi ◽  
Sophie Nitsch ◽  
Klara Janjić ◽  
Hassan Shokoohi-Tabrizi ◽  
Andreas Moritz ◽  
...  
Keyword(s):  
Fused Deposition Modeling ◽  
Cell Activity ◽  
Toxicity Assay ◽  
L929 Cells ◽  
Fused Deposition ◽  
Direct Model ◽  
Culture Models ◽  
3D Printed ◽  
The Impact ◽  
Oral Cells

Abstract Objectives LAY-FOMM is a promising material for FDA-approved Fused Deposition Modeling (FDM) applications in drug delivery. Here we investigated the impact on oral cells. Materials and methods We evaluated the impact of 3D-printed LAY-FOMM 40, LAY-FOMM 60, and biocompatible polylactic acid (PLA) on the activity of murine L929 cells, gingival fibroblasts (GF), and periodontal ligament fibroblasts (PDLF) using indirect (samples on cells), direct monolayer culture models (cells on samples), and direct spheroid cultures with resazurin-based toxicity assay, confirmed by MTT and Live-dead staining. The surface topography was evaluated with scanning electron microscopy. Results The materials LAY-FOMM 40 and LAY-FOMM 60 led to a reduction in resazurin conversion in L929 cells, GF, and PDLF, higher than the impact of PLA in indirect and direct culture models. Fewer vital cells were found in the presence of LAY-FOMM 40 and 60 than PLA, in the staining in both models. In the direct model, LAY-FOMM 40 and PLA showed less impact on viability in the resazurin-based toxicity assay than in the indirect model. Spheroid microtissues showed a reduction of cell activity of GF and PDLF with LAY-FOMM 40 and 60. Conclusion Overall, we found that LAY-FOMM 40 and LAY-FOMM 60 can reduce the activity of L292 and oral cells. Based on the results from the PLA samples, the direct model seems more reliable than the indirect model. Clinical relevance A material modification is desired in terms of biocompatibility as it can mask the effect of drugs and interfere with the function of the 3D-printed device.

Sign in / Sign up

Export Citation Format

Share Document