- Title
- Reducing the brittleness of poly-furfuryl alcohol resin used in composites
- Creator
- Pillay, Princeton
- Subject
- Textile chemistry
- Subject
- Textile chemicals
- Date Issued
- 2018
- Date
- 2018
- Type
- Thesis
- Type
- Masters
- Type
- MSc
- Identifier
- http://hdl.handle.net/10948/34350
- Identifier
- vital:33339
- Description
- The thermoset market is dominated with petroleum-based products. The rising concerns on depletion of non-renewable resources and climate change has motivated researches and industries to find green alternatives for petroleum based materials. The thermoset polymer poly-furfuryl alcohol (PFA) displays good chemical, viscoelastic and moisture stability properties and importantly is bio-based, however, the cured PFA resin is very brittle. The approach of incorporating different types of particulate fillers into the PFA matrix and reinforcing the PFA matrix with flax fabric was used to address the brittleness issue associated with PFA. In the first study, flax fabric was treated with a diammonium phosphate based flame-retardant to reduce the flammability. Compression moulding was used to produce PFA biocomposites and PFA laminates. The effect of the flame-retardant was investigated using Scanning electron microscope (SEM), x-ray diffraction (XRD), fourier transform infrared (FTIR), and cone calorimeter, flexural and tensile tests. The flame-retardant treatment significantly improved the flammability properties, however, decreased the flexural and tensile properties. In the second study, 10 different fillers were selected, these being; ZnO, Clay, montmorillonite (MMT), Rubber, Chitin, Starch, CaCO3, Chitosan, Lignin and TiO2. These fillers were incorporated into the PFA resin at 2% and 5% concentration and reinforced with untreated (UT) flax fabric and flame-retardant (FR) treated flax fabric. Flexural, tensile and izod impact tests were performed on the cured laminates. Thermogravimetric analysis (TGA), SEM and micro x-ray computed tomography scan (CT scan) analysis was performed on selected samples. The inclusion of MMT and Rubber significantly increased the strength and the stiffness of the PFA/UT-Flax laminate while Clay and ZnO reduced the brittleness of the PFA/UT-Flax laminate. FR laminates generally exhibited poor mechanical properties regardless of the type of filler. This was the result of FR damaging the flax fibres during the compression moulding process and hindered the interaction between the PFA matrix and flax fabric. TGA results showed that FR treatment increased the thermal stability of the PFA laminate. SEM and CT scan analysis illustrated the large amount of voids between fabric layers, especially for UT-Flax laminates. The fillers MMT, Rubber and ZnO had a positive effect on the mechanical properties of UT-Flax laminates and therefore were used in the third study. A Box Behnken design of experiment was developed in which the concentration of MMT, Rubber and ZnO was varied between 0 – 5%. Multiple linear regression was used to model the mechanical properties of the PFA/UT-Flax laminates based on a full quadratic model. An optimized filler combination was determined with Solver ®. The experimental results of the optimised PFA/UT-Flax laminate were compared to the values predicted with the statistical model.
- Format
- xviii, 238 leaves
- Format
- Publisher
- Nelson Mandela University
- Publisher
- Faculty of Science
- Language
- English
- Rights
- Nelson Mandela University
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