- Title
- Effect of single-walled carbon nanotubes on various properties of reclaimed rubber/natural rubber blends
- Creator
- Gumede, Jabulani Innocent
- Subject
- Carbon nanotubes
- Subject
- Nanotubes Nanostructured materials Polymers
- Date Issued
- 2019
- Date
- 2019
- Type
- Thesis
- Type
- Masters
- Type
- MSc
- Identifier
- http://hdl.handle.net/10948/39675
- Identifier
- vital:35347
- Description
- Mechanical and thermal processes are the preferred methods used to reclaim rubber from waste tyres. However, these methods produce reclaimed rubber (RR) with poor quality and lowered properties compared to virgin rubber. As a result, RR is commonly blended with virgin natural rubber (NR) in order to enhance its quality and properties to widen its application scope. The use of RR in the production of new rubber products is however limited to only about 1-10%. This is because the amounts of RR above this percentage negatively affect the properties of the resultant RR/NR blends. Researchers have used various conventional and nonconventional fillers such as carbon black and maize stalk fibres, respectively, in an attempt to enhance the properties of RR/NR blends. One main disadvantage with the use of these fillers is the need for high quantities to achieve desired properties. Several researchers have therefore focused on developing other reinforcing fillers. The fillers that have recently attracted a lot of attention of the present researchers include single-walled carbon nanotubes (SWCNTs), which are very small tubes solely made up of carbon molecules. This is because SWCNTs offer many impressive properties, and even small quantity of these nanofillers is sufficient to achieve desired properties due to their small size, large surface area and high aspect ratio. The main challenge with the use of SWCNTs however is getting them to disperse well in the rubber matrix. Therefore, their surface is either modified and then mixed with rubber or a dispersant is used to disperse them in the rubber matrix, forming a masterbatch. The common nanomaterial masterbatch product for applications in rubber is the TUBALLTM RUBBER (TR), which is a masterbatch product consisting of 1 wt. % TUBALL™ SWCNTs dispersed, using 1.5 wt.% sulfonol as a dispersant, in 97.5 wt.% NR (from latex Taytex FA). This product is a versatile masterbatch designed to enhance the mechanical, chemical, electrical and thermal properties of rubbers since it contains SWCNTs. However, the performance of this product has not been explored in the cases where recycled/reclaimed rubber is used. The main aim of this project was therefore to explore the effect of SWCNTs (via using TR) in the formulations of RR/virgin NR blends. This project was divided into two parts; (i) optimisation of SWCNTs based on tensile properties of specific formulations of compounds. These compounds were prepared by mixing various amounts of TR and NR using a Banbury internal mixer and two-roll mill. (ii) the effect of the addition of SWCNTs from the optimum SWCNTs/NR masterbatch compound on curing, mechanical, aging, dynamic mechanical and thermal properties of RR/NR blends was studied. Curing properties explored include minimum torque (ML), maximum torque (MH), scorch time (ts0.5), curing time (t90) and cure rate. Mechanical properties studied are tensile strength, modulus at 100%, 200%, 300% and 500% elongation, elongation at break, hardness and resilience. Dynamic mechanical properties include stiffness, storage modulus (E'), loss modulus (E''), loss tangent delta (tanδ) and glass transition temperature (Tg). Thermal degradation (stability) was studied by means of thermogravimetric analysis (TGA) for analysing the effect of SWCNTs inclusion on RR/NR blends. The optimum SWCNTs/NR masterbatch compound contained 0.1 wt. % of SWCNTs. The results obtained for various properties indicate that SWCNTs from the optimum SWCNTs/NR masterbatch compound enhanced the curing, mechanical, aging and dynamic mechanical properties of RR/NR blends with lower RR loading. Thermal properties of RR/NR blends were found to be unaffected by the addition of SWCNTs. However, owing to their impressive properties, the use of SWCNTs as nanofillers in RR/NR blends have the greatest potential for extending the applications of RR/NR blends.
- Format
- xvii, 122 leaves
- Format
- Publisher
- Nelson Mandela University
- Publisher
- Faculty of Science
- Language
- English
- Rights
- Nelson Mandela University
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NMU School of BioMolecular and Chemical Sciences
| Thumbnail | File | Description | Size | Format | |||
|---|---|---|---|---|---|---|---|
| View Details Download | SOURCE1 | JABULANI INNOCENT GUMEDE.pdf | 3 MB | Adobe Acrobat PDF | View Details Download |