Natural fibers based ecofriendly composites for lightweight and 3D printing applications

Name: Vinod Ayyappan

keyword: Bioepoxy

LCSH: Three-dimensional printing

; Ecofriendly composites

LCSH: Plant fibers

; Natural fibers composite

LCSH: Fibrous composites

LCSH: Agricultural wastes

LCSH: Morinda Citrifolia

Abstract: Over the recent decades, rapid industrialization resulted in the abundant utilization of plastics and manmade synthetic materials. This created hazardous effects on the environment during their disposal by polluting the land, water, and air. To resolve this issue, researchers and industries had come up with the idea of utilizing plant fibers as a replacement for synthetic materials. The use of eco-friendly products from natural fibers significantly reduces the carbon footprint. Despite their excellent properties, there are some limitations like compatibility, low strength, hydrophobicity, and irregular structural gradation. Additionally, there are other shortcomings like limited geographical location, and demand for the sustainability of raw material supplies. These limitations can be overcome by chemical modification techniques and by identifying new resources. In the first two phases of the current research, novel natural plant fibers were identified from the agro-wastes to support sustainability, and their composites were developed through the mold casting method. In the third phase, natural fiber composites reinforced with thermally stable fibers were developed using 3D printing process. Finally, a few prototypes were 3D printed using the developed 3D printing natural fiber feedstock filament. In the first phase of research, the agro-waste Soy stem after the harvest is identified as a sustainable resource of raw material. The Soy fibers were extracted, cleaned, and subjected to chemical treatment. The chemical analysis revealed an increase in cellulose content up to 26% and 39% for the oxalic acid and silane-treated Soy fibers, respectively. The silane treatment further improved the thermal stability of Soy fibers up to 352.56°C and reduced the coefficient of thermal expansion of its composites up to 82.03ppm(˚C-1). The composites with silane-treated fibers showed better mechanical performance when compared to untreated and other chemical-treated FRC (Fiber Reinforced Composites). However, the oxalic acid treatment showed better mechanical performance when compared to traditional NaOH treatment. From the results, it is observed that Soy stem fiber is a sustainable and renewable resource of raw material that can be used as reinforcements in polymer matrices for lightweight structural applications. In the second phase, another new novel resource of natural fiber is identified from the Agro-waste of Morinda Citrifolia (MC), and attempts were made to bridge the gap between the materials and sustainability. The fibers were subjected to chemical treatments like NaOH, silane, and nitric acid to improve their compatibility. The thermal stability of silane-treated MC was increased up to 362.73°C. From the results, it was noted that the MC fibers were more thermally stable when compared to the Soy stem fibers. The mechanical lifetime of the best-performed composite under dynamic loading is analyzed and studied through a fatigue test. Finally, from the results, it is found that MC fiber is a novel potential resource of sustainable raw material for reinforcement in polymer composites. Due to good thermal stability, the MC fiber is found to be suitable for 3D printing lightweight FRC products. In the third phase, attempts were made to 3D print the Morinda Citrifolia fiber-reinforced PLA composite. The applications of natural fibers in fused deposition modeling (FDM) are very limited and needed to be explored more. The reinforcement with natural fibers enhances the mechanical strength of the 3D printing filaments and their 3D printed specimens. Eco-friendly materials aid to overcome environmental concerns like emission and pollution by replacing synthetic materials. Polylactic acid (PLA) 3D printing filaments were developed with 1.75mm diameter by varying the volume % of Morinda Citrifolia bark fibers (MCBF). The 3D-printed FRC specimens are subjected to mechanical, thermo-mechanical, and visco-elastic analysis. The test results revealed that the filaments with 6 volumes % of MCBF, showed 15% improvement in tensile strength, and 25% in flexural strength. Finally, from the results, it was confirmed that the developed MCBF reinforced filaments could be used as a potential feedstock filament material. Additionally, it could be used to manufacture various customized lightweight products in the automotive and sports industries (customized cycling helmets, protective/knee guards, and prototypes).

King Mongkut's University of Technology North Bangkok. Central Library

Address: BANGKOK

Email: library@kmutnb.ac.th

Name: Suchart Siengchin

Role: dissert advisor

Email : suchart.s.pe@tggs-bangkok.org

Name: Sanjay Mavinkere Rangappa

Role: dissert advisor.

Email : mavinkere.r.s@op.kmutnb.ac.th

Created: 2022

Modified: 2567-09-02

Issued: 2024-09-02

วิทยานิพนธ์/Thesis

application/pdf

eng

DegreeName: Doctor of Engineering

Level: Doctoral Degree

Descipline: Materials and Production Engineering (International Program)

Grantor: King Mongkut's University of Technology North Bangkok

©copyrights King Mongkut's University of Technology North Bangkok

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