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- Sundar, Smith T., et al.
(författare)
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Characterization of microcrystalline cellulose and cellulose long fiber modified by iron salt
- 2010
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Ingår i: Carbohydrate Polymers. - : Elsevier BV. - 0144-8617 .- 1879-1344. ; 80:1, s. 35-43
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Tidskriftsartikel (refereegranskat)abstract
- Microcrystalline cellulose (MCC) and cellulose long fiber (CLF) were treated with iron (Fe) based salt and the samples were characterized to study the coordination complexes formed between cellulose and iron. The Fe-modified MCC and CLF were characterized by spectroscopic, thermal and morphological methods. MCC and CLF were oxidized and further treated with iron (Fe) based salt in a high pH medium to form coordination complexes. Both MCC and CLF were then analyzed using Scanning electron microscopy (SEM) to examine their surface morphology. The results have shown that there was no major change in morphology for MCC and CLF upon modification. The functional groups formed by modifying cellulose by iron salt were investigated using FTIR-ATR spectroscopy and the nature of the coordination bonds formed between cellulose and Fe ions were examined by X-ray photo electron spectroscopy (XPS). The results agree that coordination bonds were formed between de-protonated and or oxidized hydroxyl group and Fe ions. Powder XRD (PXRD) was resourceful to compare the crystallinity of unmodified and Fe-modified samples of MCC and CLF. Thermal stability of modified cellulose was studied using thermo gravimetric analysis (TGA). The results showed that there was an increase in percentage of residual mass and higher thermal stability for the Fe-modified MCC and CLF compared to unmodified samples due to the presence of iron.
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- Sundar, Smith, et al.
(författare)
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Thermal characterization and electrical properties of Fe-modified cellulose long fibers and micro crystalline cellulose
- 2011
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Ingår i: Journal of thermal analysis and calorimetry (Print). - : Springer Science and Business Media LLC. - 1388-6150 .- 1588-2926 .- 1572-8943. ; 104:3, s. 841-847
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Tidskriftsartikel (refereegranskat)abstract
- Thermal properties of polylactic acid (PLA) filled with Fe-modified cellulose long fibers (CLF) and microcrystalline cellulose (MCC) were studied using thermo gravimetric analysis (TG), differential scanning calorimetry, and dynamic mechanical analysis (DMA). The Fe-modified CLFs and MCCs were compared with unmodified samples to study the effect of modification with Fe on electrical conductivity. Results from TG showed that the degradation temperature was higher for all composites when compared to the pure PLA and that the PLA composites filled with unmodified celluloses resulted in the best thermal stability. No comparable difference was found in glass transition temperature (Tg) and melting temperature (Tm) between pure PLA and Fe-modified and unmodified CLF- and MCC-based PLA biocomposites. DMA results showed that the storage modulus in glassy state was increased for the biocomposites when compared to pure PLA. The results obtained from a femtostat showed that electrical conductivity of Fe-modified CLF and MCC samples were higher than that of unmodified samples, thus indicating that the prepared biocomposites have potential uses where conductive biopolymers are needed. These modified fibers can also be tailored for fiber orientation in a matrix when subjected to a magnetic field
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