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https://ptsldigital.ukm.my/jspui/handle/123456789/499622| Title: | Extraction of cellulose nanocrystal from mengkuang leaf (pandanus tectorius) and its application as nanofiller in polyvinyl chloride and polyvinyl chloride/epoxidized natural rubber composites |
| Authors: | Rasha Mohamed Farhat El. Sheltami (P48793) |
| Supervisor: | Ibrahim Abdullah, Prof. Dr. |
| Keywords: | Cellulose nanocrystals Pandanus tectorius Mengkuang leaves Bleaching treatments Dissertations, Academic -- Malaysia Universiti Kebangsaan Malaysia -- Dissertations |
| Issue Date: | 18-Nov-2015 |
| Description: | The aims of this study were to produce cellulose nanocrystals (CNC) from local plant for use as nanoreinforcement in a polymer matrix and its blends. The CNC was isolated from mengkuang leaves (Pandanus tectorius) by carrying out alkali and bleaching treatments followed by concentrated sulphuric acid hydrolysis. The mengkuang leaf extract consisted of about 10.4 wt.% of cellulose nanocrystals with diameters in the range of 5-25 nm and crystallinity percentage of 74%. The thermal stability of the leaf extract increased at various purification stages. Surface modification of CNC with silane as the coupling agent [N-(β-aminoethyl)-γ-aminopropyl-trimethoxysilane (AEAPTMS)] was conducted to improve its adhesion to the polymer matrices. The nanocrystals, CNC and silane modified CNC (SCNC), were applied as nanoreinforcement filler in polyvinyl chloride (PVC) and oly(vinyl chloride)/epoxidized natural rubber (PVC/ENR) blend. The nanocomposites were prepared via solution casting technique. The morphological observation showed uniform distribution of CNC in the PVC and PVC/ENR matrices which was attributed to the good compatibility between the nanofiller and the polymer matrices. The tensile strength had increased after incorporation of CNC from about 29 MPa to 32 MPa for PVC, 21 MPa to 22 MPa for 50/50 PVC/ENR blend and 13 MPa to 14 MPa for 30/70 PVC/ENR blend, at the optimum loading of CNC (2 wt.%). The improvement in tensile strength showed the reinforcement effect of CNC in both PVC and PVC/ENR matrices. The use of SCNC in PVC nanocomposites enhanced the tensile strength as compared to the neat PVC and CNC in PVC. At the optimum loading of SCNC (4 wt.%), the tensile strength was 39 MPa, which showed an improvement of 35% over the matrix. In nanocomposites of PVC/ENR, the tensile strength reduced upon addition of SCNC. On the other hand, thermogravimetric analysis (TGA) showed that both nanofillers (CNC and SCNC) had no significant effect on the thermal stability of the nanocomposites. Dynamic mechanical thermal analysis (DMTA) showed an improvement in storage modulus of the nanocomposites in the rubbery region, but no major improvement in the glassy state. The nanofillers had different effects on the water absorption at equilibrium of the matrices. The incorporation of both nanofillers into PVC showed a slight increment in the maximum water absorption but drastically reduced for PVC/ENR. The study demonstrated the potential of extracting CNC from mengkuang leaves and to apply it as nanofiller in both PVC and PVC/ENR systems. In addition, AEAPTMS was effective in surface modification of CNC in enhancing the inter-facial interaction in the PVC/CNC nanocomposites.,Ph.D. |
| Pages: | 186 |
| Publisher: | UKM, Bangi |
| Appears in Collections: | Faculty of Science and Technology / Fakulti Sains dan Teknologi |
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|---|---|---|---|---|
| ukmvital_80364+SOURCE1+SOURCE1.0.PDF Restricted Access | 382.29 kB | Adobe PDF |  View/Open |
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