Effects of electron beam irradiation on the properties of recycled polypropylene/microcrystalline cellulose composites /

The poor compatibility between a thermoplastic matrix and natural fibre reinforcement has been a limitation to develop high performance natural fibre-filled composites. Electron beam irradiation is employed to modify the structure of materials. However, most researches have focused on the effect of...

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Bibliographic Details
Main Author: Nurul Hakimah binti Mohd Lazim (Author)
Format: Thesis
Language:English
Published: Kuala Lumpur : Kulliyyah of Engineering, International Islamic University Malaysia, 2017
Subjects:
Online Access:http://studentrepo.iium.edu.my/handle/123456789/4732
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Summary:The poor compatibility between a thermoplastic matrix and natural fibre reinforcement has been a limitation to develop high performance natural fibre-filled composites. Electron beam irradiation is employed to modify the structure of materials. However, most researches have focused on the effect of irradiation after the fabrication of composites. Hence, this study was aimed at investigating the effect of irradiated recycled polypropylene (i-rPP) as a compatibilizer in recycled polypropylene composites. The rPP were irradiated at different doses before the compounding process. The rPP matrices were prepared by mixing the unirradiated and irradiated rPP (10, 20, 30 and 50 kGy) at ratios of 90:10 and 50:50, before being compounded with different amounts of microcrystalline cellulose (MCC) fibres (5, 20 and 40 wt%) by using twin screw extruder and injection moulding. The effectiveness of EB irradiation was analyzed based on the mechanical, thermal, and structural tests of the fabricated composites. It was found that the i-rPP compatibilizer caused an increase in the degree of crosslinking, storage modulus, glass transition temperature and crystallinity of rPP. The addition of i-rPP and MCC fibres significantly improved the tensile and flexural modulus of rPP. Nevertheless, the tensile and flexural strength of rPP: i-rPP/MCC composites showed slight improvement. The thermal stability was acceptable. The formation of carbonyl groups and high peroxy radical concentration in 90:10/40MCC samples caused a decrease in the impact strength. A compatibilizing effect of i-rPP was evident by good interfacial adhesion between MCC fibres and rPP matrix in FESEM morphology. The fractography analysis revealed the crack blunting effect that contributed to a significant increase in the impact strength of 50:50/40MCC-10kGy sample.
Item Description:Abstracts in English and Arabic.
"A dissertation submitted in fulfilment of the requirement for the degree of Master of Science (Materials Engineering)." --On title page.
Physical Description:xvi, 109 leaves : illustrations ; 30cm.
Bibliography:Includes bibliographical references (leaves 98-108).