Characterization of kenaf bast fibre filled poly (butylene succinate) composites: mechanical, water absorption and weathering properties.
| dc.contributor.author | Ahmad Thirmizir, Mohd Zharif | |
| dc.date.accessioned | 2015-09-03T08:24:59Z | |
| dc.date.available | 2015-09-03T08:24:59Z | |
| dc.date.issued | 2011 | |
| dc.description.abstract | Characterization of kenaf bast fibre (KBF) filled poly(butylene succinate) (PBS) composites in this study involved several stages. Firstly, the effect of KBF loadings (l0 - 40 wt. %) on flexural and impact properties were investigated. The flexural strength of the composites increased with increasing fibre loadings up to 30 wt. % with the highest value of about 9.4 % before decreasing with a further increase in fibre loading. The flexural modulus of the composites increased about 87.1 - 424 % with increasing KBF loadings from 10 to 40 wt. %. This indicates that the addition of KBF at 30 wt. % loading had resulted in a balance of performance and processability of the composites. However, the stiff nature of the KBF resulted in the reduction of the composites' impact strengtll. Secondly, the effect of fibre length (5, 10, 15 and 20 mm KBF) on the mechanical properties was investigated at fibre loading of 30 wt. %. Composite with 10 mm KBF length showed the highest increment in flexural strength and modulus of about 16.7 and 3.6%, respectively. The inferior flexural and impact strength of the composites with 15 rom and 20 mm KBF length could be due to the relatively longer fibres that underwent severe fibre attrition as a result of high mechanical shearing during the compounding. This was proven by analysis of the fibre length, diameter and aspect ratio. Third stage focused on the improvement of fibre-matrix interfacial adhesion by an introduction of unpurified and purified maleated PBS compatibilisers. For preparation of PBSgMA, DCP initiator concentration was kept constant at 1 phr while MA concentration was varied from 3 - 10 phr. The optimum enhancements in flexural and impact strength were observed in both composites with addition of 5 wt. % unpurified and purified compatibilisers at 5 phr MA concentration. The inferior mechanical properties of the composites with unpurified compatibilisers to those with purified compatibilisers probably due to the presence of unreacted MA in the unpurified compatibilisers which could restrict the formation of complete bridging between matrix and fibres. The last stage involved evaluation of water absorption and natural weathering performance on both the uncompatibilised and compatibilised PBSIKBF composites. Increment about 2.49 to 12.5 wt.% in equilibrium water content (Mm) were observed for uncompatibilised composites with increasing fibre loading from 10 to 40 wt. %. This was attributed to the presence of more hydrophilic KBF in the composites. On the contrary, the Mm for the composites with purified compatibilisers at concentrations of MA 3 - 7 phr were lower than that of uncompatibilised composite. This may be due to the formation of a good fibre-matrix interfacial adhesion with the presence of purified compatibiliser. The deteriorating impact of water on the composites was proven by reduction in the flexural properties and degradation of the composites' structure after exposed to 90 days water immersion. Exposure of both uncompatibilised and compatibilised composites to natural weathering for a period of 6 months resulted in a decrease of the flexural properties due to severe photo- and thermal-oxidation degradation during the exposure. However, the reduction in flexural properties upon natural weathering observed for the composites with purified compatibilisers was higher than the uncompatibilised composites due to the higher content of chemical groups of the former, which were more susceptible to undergo oxidation during weathering. The degradation of specimens upon weathering was also proven by FTIR analysis, SEM examination and colour change analysis. | en_US |
| dc.identifier.uri | http://hdl.handle.net/123456789/1172 | |
| dc.language.iso | en | en_US |
| dc.title | Characterization of kenaf bast fibre filled poly (butylene succinate) composites: mechanical, water absorption and weathering properties. | en_US |
| dc.type | Thesis | en_US |
Files
License bundle
1 - 1 of 1
Loading...
- Name:
- license.txt
- Size:
- 1.71 KB
- Format:
- Item-specific license agreed upon to submission
- Description: