Biochar Based Composite Material: Study of Mechanical and Physicochemical Properties
Date
2025-03-10
Authors
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ORCID
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Thesis
Degree Level
Masters
Abstract
This research explores the development of sustainable polymer composites by using carbon-based materials to reinforce them and assess their mechanical and thermal properties. With the growing need for eco-friendly materials, biochar a renewable material derived from agricultural or organic waste emerges as a promising candidate to enhance polymer composites' performance, providing a sustainable alternative to traditional materials.
In this study, polymer composites were created by incorporating various amounts of carbon-based reinforcements. The main polymers investigated were polylactic acid (PLA), low-density polyethylene (LDPE), and linear low-density polyethylene (LLDPE). To determine the effects of biochar, mechanical properties such as TS, YM, and EB were measured. Additionally, changes in the composites' density with increasing biochar content were evaluated. A comparative analysis was also conducted with carbon black, a known filler, to see how different carbon-based materials perform.
Results showed that increasing biochar content led to higher composite density, attributed to the greater mass and packing density of biochar particles within the polymer matrix. However, the mechanical properties did not follow a consistent pattern of improvement with higher biochar content. Instead, the impact on these properties varied depending on the polymer matrix and the amount of biochar used. Although biochar increased the material’s density effectively, its influence on mechanical behavior was complex and multifaceted. The inclusion of carbon reinforcement typically reduced the composites' plastic properties but adding 10% polyethylene glycol (PEG) helped restore these properties closer to those of the original polymer.
Thermal properties were examined using Differential Scanning Calorimetry (DSC). The analysis revealed that the heat flow and melting points of biocomposites increased with higher biochar content. For PLA-based composites, the melting point increased by 11°C with 40% biochar, while for LDPE and LLDPE, the melting point rose by 25°C with the same reinforcement percentage. These findings indicate that biochar enhances the density and thermal stability of polymer composites, while its impact on mechanical properties remains
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variable. The decrease in Melt Flow Index (MFI) was linked to the composites' elevated melting points, affecting their flow properties during processing. Moisture absorption tests demonstrated that composites with carbon reinforcement had notable water uptake due to pore formation and increased surface area, with LDPE and LLDPE composites showing about 0.6% absorption, while PLA composites reached 1.6%.
This research supports the ongoing efforts to develop more sustainable composite materials, with potential applications across various industrial sectors.
Description
Keywords
Biochar, extruder
Citation
Degree
Master of Science (M.Sc.)
Department
Chemical and Biological Engineering
Program
Chemical Engineering