Study on the 3D printability of poly(3-hydroxybutyrate-co-3-hydroxyvalerate)/poly(lactic acid) blends with chain extender using fused filament fabrication

Abstract Composite filaments consisting of poly(lactic acid) (PLA) and micro crystalline cellulose (MCC) were successfully used for additive manufacturing (AM) by fused filament fabrication (FFF). PLA and MCC bio-composites were obtained by direct mixing in a melt compounder; maleic anhydride (MAH) was also grafted onto PLA in reactive mixing stage to evaluate its effect on the final properties of the printed material. Filaments with various concentrations of MCC (up to a maximum content of 10 wt%) were produced with a single screw extruder and used to feed a commercial desktop FFF printer. Upon grafting of PLA with MAH, a more coherent interfacial morphology between PLA and MCC was detected by electron microscopy analysis. The thermal degradation of the PLA was unaffected by the presence of MCC and MAH. According to differential scanning calorimetry and dynamic mechanical analysis results, micro-cellulose acted as nucleating agent for PLA. In fact, the crystallization peak shifted towards lowers temperature and a synergistic effect when MCC was added to PLA grafted with MAH was observed possibly due to the increase of the chain mobility. Micro cellulose led to an increase in the stiffness of the material in both filaments and 3D printed specimen, however, a different fracture behavior was observed due to the peculiar structure of printed samples.

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Evaluation of the Deterioration of the Mechanical Properties of Poly(lactic acid) Structures Fabricated by a Fused Filament Fabrication 3D Printer

Inventions ◽

10.3390/inventions4010021 ◽

2019 ◽

Vol 4 (1) ◽

pp. 21 ◽

Cited By ~ 3

Author(s):

Miho Suzuki ◽

Asahi Yonezawa ◽

Kohei Takeda ◽

Akira Yamada

Keyword(s):

Mechanical Properties ◽

Lactic Acid ◽

Tensile Tests ◽

Poly Lactic Acid ◽

3D Printer ◽

Fused Filament Fabrication ◽

Tensile Direction ◽

Test Pieces ◽

3D Printers ◽

Scan Pattern

A fused filament fabrication (FFF) 3D printer is a simple device capable of manufacturing three-dimensional structures in a series of easy steps. Commercial-level FFF 3D printers have spread rapidly in many fields in recent years. Poly(lactic acid) (PLA) is a biodegradable thermoplastic polymer used as a typical printing medium for FFF 3D printers. The FFF printer constructs an object with melted polymer extruded from a tiny scanning nozzle. The mechanical properties of FFF 3D structures printed with different scan patterns can therefore vary in accordance with the directions from which forces act upon them. The nozzle scan pattern also influences the deterioration of the mechanical properties of the structures in accordance with the degradation caused by the hydrolysis of PLA. In this study we conducted tensile tests to evaluate the strength characteristics of 3D printed test pieces formed from PLA using four different scan patterns: parallel, vertical, parallel-and-vertical, and cross-hatched at opposing diagonal angles to the tensile direction. We also formed test pieces by an injection molding method using the same material, for further comparison. We evaluated the deterioration of the test pieces after immersing them in saline for certain periods. After the test pieces formed by different nozzle scan patterns were immersed, they exhibited differences in the rates by which their maximum tensile stresses deteriorated and their masses increased through water uptake. The influences of the scan patterns could be classified into two types: the unidirectional scan pattern influence and bidirectional scan pattern influence. The data obtained in this research will be applied to structural design when the FFF 3D printer is employed for the fabrication of structures with PLA filament.

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Effect of a chain extender on the rheological and mechanical properties of biodegradable poly(lactic acid)/poly[(butylene succinate)-co-adipate] blends

Journal of Applied Polymer Science ◽

10.1002/app.38449 ◽

2013 ◽

Vol 129 (5) ◽

pp. 2418-2428 ◽

Cited By ~ 46

Author(s):

Hassan Eslami ◽

Musa R. Kamal

Keyword(s):

Mechanical Properties ◽

Lactic Acid ◽

Chain Extender ◽

Poly Lactic Acid ◽

Butylene Succinate ◽

Biodegradable Poly ◽

A Chain

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Effects of the chain-extender content on the structure and performance of poly(lactic acid)-poly(butylene succinate)-microcrystalline cellulose composites

Journal of Applied Polymer Science ◽

10.1002/app.44895 ◽

2017 ◽

Vol 134 (22) ◽

Cited By ~ 6

Author(s):

Zheng Cao ◽

Ying Lu ◽

Cheng Zhang ◽

Qian Zhang ◽

An Zhou ◽

...

Keyword(s):

Lactic Acid ◽

Microcrystalline Cellulose ◽

Chain Extender ◽

Poly Lactic Acid ◽

Butylene Succinate ◽

Cellulose Composites ◽

And Performance

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Valorization of poly(lactic acid) wastes via mechanical recycling: Improvement of the properties of the recycled polymer

Waste Management & Research ◽

10.1177/0734242x18798448 ◽

2018 ◽

Vol 37 (2) ◽

pp. 135-141 ◽

Cited By ~ 2

Author(s):

F.R. Beltrán ◽

I. Barrio ◽

V. Lorenzo ◽

B. del Río ◽

J. Martínez Urreaga ◽

...

Keyword(s):

Lactic Acid ◽

Food Packaging ◽

Fossil Fuel ◽

Chain Extender ◽

Poly Lactic Acid ◽

Recycling Process ◽

Mechanical Recycling ◽

Improved Performance ◽

Recycled Polymer ◽

Recycled Material

Poly(lactic acid) (PLA) is a biobased polymer that represents one of the most interesting alternatives to fossil-fuel based polymers in food packaging applications. Most of the PLA used in food packaging is used only once and then discarded, even though the PLA types used in packaging have good properties and stability. Therefore, it seems reasonable to consider the possibility of recycling the used polymer through a mechanical recycling process. The main aims of this work are to study the effect of the mechanical recycling on the properties of PLA and the usefulness of different upgrading methods to obtain recycled PLA with improved properties. A commercial type of PLA was subjected to accelerated thermal, photochemical and hydrolytic aging and then reprocessed. During reprocessing, aged PLA was blended with virgin PLA and a commercial chain extender was added. Results point out that recycling causes the degradation of PLA, and negatively affects the thermal stability and mechanical properties. However, addition of virgin PLA, and the chain extender, led to an increase of up to 9% in the intrinsic viscosity and 8% in the Vickers hardness of the recycled material. These results suggest that mechanically recycled PLA with improved performance can be obtained, a fact which might improve the recyclability of PLA and thus the environmental impact of this material.

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Effect of chain extender on morphologies and properties of PBAT/PLA composites

Journal of Thermoplastic Composite Materials ◽

10.1177/08927057211051415 ◽

2021 ◽

pp. 089270572110514

Author(s):

Jing Sun ◽

Anrong Huang ◽

Shanshan Luo ◽

Min Shi ◽

Jiling Song ◽

...

Keyword(s):

Mechanical Properties ◽

Lactic Acid ◽

Rheological Properties ◽

Chain Extender ◽

Poly Lactic Acid ◽

Melt Blending ◽

Elongation At Break ◽

Increasing Trend ◽

Biodegradable Poly ◽

Interfacial Compatibility

Biodegradable poly(butylene adipate-co-terephthalate)/poly(lactic acid) (PBAT/PLA) composites were prepared by melt blending, and chain extender was used to improve the compatibility of PBAT/PLA blends through the chemical reaction. The influence of PLA and chain extender contents on mechanical properties, morphology, and rheological properties of PBAT/PLA composites was systematically investigated. The results revealed that the Young’s modulus and stress values gradually increased under the same strain, whereas the elongation at break decreased with the increase of chain extender content for PBAT/PLA (80/20) composites. Noteworthy, the presence of chain extender improves the interfacial compatibility between PLA and PBAT phases. At the chain extender content of 0.4, 0.6, and 0.8 wt.%, the extensional viscosity of the composites exhibited an increasing trend, whereas an obvious strain-hardening phenomenon emerged in the uniaxial extensional curves.

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