Papers by Keyword: Cellulose

Abstract: Bioplastic composites of carboxymethyl cellulose (CMC) and N-P-K fertilizer have been prepared at various amount of N-P-K. The bioplastics were prepared by solvent casting the sol precursors containing 10 to 50% (wt.%) commercial N-P-K fertilizer powder in petri dishes. Characterization was done by using infrared spectrophotometer to access the functional groups, XRD to evaluate the crystalline phase, and universal testing machine to determine the mechanical properties. The nitrogen and phosphorus contents were determined by UV-Vis spectrophotometer, while the potassium content was determined by using atomic absorption spectrometer. The results show that the bioplastic composites of CMC/N-P-K fertilizer can be prepared up to 40% (wt.%) of N-P-K powder without losing its plasticity. The mechanical properties of the resulted bioplastic composites decrease at high content of N-P-K powder, with the highest at 25 wt.%. The uptake of nitrogen and phosphorous was not affected by the amount of the N-P-K powders precursor, but the potassium was. Various possible interactions between N-P-K powder and CMC matrix allow the resulting composite to function as a controlled release of N-P-K fertilizer.

Abstract: Empty fruit bunches fibre (EFB) consisting of 44 % cellulose, 16 % lignin and 35 % hemicelluloses component was treated using microwave-alkali (Mw-A) agitated pre-treatment so as to disrupt the recalcitrant structures in the fibre. Morphology and chemical changes of treated EFB were used as indicators to the effectiveness of Mw-A treatment. The results obtained were compared with conventional pre-treatment process. The morphology of the treated fiber was observed using scanning electron microscope. The reduction in the EFB composition during Mw-A treatment was justified by measuring the total extract cellulose; remaining lignin and hemicellulose, and ash content after the process was performed. Results revealed that Mw-A pre-treatment technique exhibited a more effective removal of lignin and hemicelluloses as compared to the conventional or chemical treatment.

Abstract: Lignocellulosic fibers have attracted the attention of researchers, academicians and industries in recent years. These fibers have several advantages as compared to conventionally used fibers such as availability in abundance in nature as it can be extracted from almost every plants, biodegradability, environmental friendliness, high specific strength, etc. Cellulose content of fiber depends on the chemical constituents of the source plant from which it is extracted hence it becomes necessary to understand the constituents of lignocellulosic fibers before its application. In this paper, a new source (Delonix Regia Fruit) of cellulosic fibers has been evaluated and chemical constituents of Delonix Regia fruit fiber has been compared with several lignocellulosic plant fibers. Also, Delonix Regia Fruit fibers are presented as a new source of cellulose and Chemical methods are used for extraction of cellulose from it. Chemically Treated and untreated fibers are characterized by Fourier Transform Infrared Spectroscopy (FT-IR) and Thermo Gravimetric Analysis (TGA) to understand the effect of chemical treatment, properties of the cellulose yield. From the results compositional analysis it can be seen that Delonix Regia fruit fibers have 66.9% cellulose content which is very high as compared to most of the popular sources which makes it suitable and cost effective to extract cellulose from it and can be used in biocomposites and bionanocomposites. Analysis of FT-IR spectra of untreated and chemically treated Delonix Regia Fruit Fibers revealed the removal of hemi-cellulose and lignin by chemical treatments followed. TGA-DTG results proved that highly purified yield of cellulose is successfully extracted by the chemical route followed.

Abstract: This work studied the effects of various types of cellulose fibers on the morphology, mechanical and thermal properties of poly(lactic acid) (PLA)/propylene-ethylene copolymer (PEC) (90/10 w/w) blends. The PLA/PEC blends before and after adding cellulose fibers were prepared by melt blending method in the internal mixer and molded by compression method. The morphological analysis observed that the presence of cellulose in PLA did not change the phase morphology of PLA, and PLA/cellulose composite surfaces were observed the cellulose fibers inserted in PLA matrix and fiber pull-out. The phase morphology of PLA/PEC blends was changed from brittle fracture to ductile fracture behavior and showed the phase separation between PLA and PEC phases. The presence of celluloses did not improve the compatibility between PLA and PEC phases. The tensile stress and strain curves found that the tensile stress of PLA was the highest value. The addition of all celluloses increased Young’s modulus of PLA. The PEC presence increased the tensile strain of PLA over two times when compared with neat PLA and PLA was toughened by PEC. The incorporation of cellulose fibers in PLA/PEC blends could improve Young’s modulus, tensile strength, and stress at break of the blends. The thermal stability showed that the degradation temperatures of all types of cellulose were less than the degradation temperatures of PLA. Thus, the incorporation of cellulose in PLA could not enhance the thermal stability of PLA composites and PLA/PEC composites. The degradation temperature of PEC was the highest value, but it could not improve the thermal stability of PLA. The incorporation of cellulose fibers had no effect on the melting temperature of the PLA blend and composites.

Abstract: Hydrogels are smart materials that have the capability to absorb water by over five hundred times their own weight and showed various applications in biomedical field, including drug delivery systems, tissue engineering and wound healing. In this study, the fabrication of polyvinyl alcohol hydrogels reinforced with cellulose and silica nanoparticles was investigated for possible use in wound healing applications. Synthesis was done through chemical cross-linking of polyvinyl alcohol and sodium borate. Results showed that mechanical properties and thermal stability of the reinforced hydrogels were improved compared to the neat hydrogel. The nanosilica-reinforced hydrogels showed antimicrobial activity and improved degree of swelling compared to the neat PVA hydrogels. Sparse growth was observed in the antimicrobial assay with Pseudomonas aeruginosa and Staphylococcus aureus. Cellulose-reinforced hydrogels showed minimal flexibility characteristic compared to the nanosilica-reinforced hydrogel samples. Moreover, it showed no antimicrobial activity against Pseudomonas aerigunosa.

Abstract: The silica potassium humic substance (Si-K-HAs) composite have been produce by spray drying successfully. In the previous study the preparation of Si-K-HAs gel by precipitation method required the addition of acid so that Si-K-HAs gel product contains acid salts. This study was develope spray drying method in order to eliminate the use of acid. The mixture of potassium silicate, cellulose and humic potassium solution was mixed with varying volume ratios and flowed into a spray dryer to produce Si-K-HAs powder. The used of cellulose (CMC) in this study acts as a homogeneous agent so that silica and humic substance can be completely mixed at controlled viscosity. Si-K-HAs products were characterized by Scanning electron microscopy (SEM), X-ray fluorescence (XRF), X-ray diffraction (XRD), Fourier transform infrared spectrometry (FTIR), and Surface area analytical (SAA). The result showed that the Si-K-HAs composite prepared by spray dryers have spherical particles, SiO₂ in the range of 48-50%, K₂O in the range of 49-50%. The present of cellulose caused the increasing of Si-K-HAs particle size e.g 17.30 μm prepared without CMC to 41.11 μm prepared with addition of 100g of CMC. The presence of cellulose can also increase the surface area of the spray-dried Si-K-HAs particles from 111.92 m²g^-1; 163.241 m²g^-1.

Abstract: This study reports on the development of an iron oxide-cellulose composite material for the controlled removal of 4-hydroxy-3-nitrobenzenearsonic acid (roxarsone), a model organoarsenical. Hematite (He) and a hematite-cellulose (HeCell) composite adsorbents were prepared and characterized by thermal gravimetric analysis (TGA), nitrogen adsorption, and various spectroscopic (IR, Raman, XRD, and TEM) methods. The uptake of roxarsone at ambient conditions of He and HeCell, and goethite-cellulose (GoCell) adsorbent were compared to study the factors that influence adsorption. The monolayer adsorption capacity (mmol/g) of each adsorbent are listed in parentheses, as follows: cellulose (0.028), goethite (0.0730), Hematite (0.155), 10 % Fe coated GoCell (0.0222) and 10% Fe coated HeCell (0.0873). The relatively large surface area of hematite nanoparticles (NPs) and good dispersion of these NPs onto the cellulose supports contribute to their effective adsorption of roxarsone.

Abstract: Recycling of paper materials or other type of cellulose fibres is important regarding saving nature resources and environmental protection. Cellulose dissolution and regenerating from various materials is one of recycling possibilities. Cellulose dissolution by NaOH/urea system has a great potential due to the use of harmless reagents, and at the same time is challenging due to the forming of gel-like substances, when cellulose has degree of polymerization more than 1000. It was found that microcrystalline cellulose and cotton cellulose were dissolved in NaOH/urea, but tissue paper, filter paper and waste paper were not dissolved completely. Additives of Kraft pulp and pulp waste dissolved and regenerated from NaOH/urea and cupriethylendiamine (CuETD) in amount 0-30% from paper composition increased mechanical properties of paper sheet. CuETD additive was more effective than NaOH/urea additive, however latter has potential for further research as environmentally friendlier.

Abstract: Today, due to environmental reasons and limited of fossil resources take many researchers to develop new and renewable materials. Bio-composites which is consisted of synthetic polymers matrix and natural fibres, is one of the alternatives to reducing its problems. Among of natural fibre that has good potential to be used as reinforcement in synthetic polymer matrices is sorghum fibre. However the hydrophilic nature of natural fibers causes it to be incompatible with synthetic polymer matrices which have hydrophobic properties and it’s need to surface modified with particular treatment. The aim of this work was conducted to study the effect of hydrothermal treatment through pressure boiled method by using distilled water in a pressurized stainless steel pan cooking for 5 minutes to defibrillation and hydrophilic properties of stalk sweet sorghum fibres. Evaluation of the experiments was characterized with Field-Emission Scanning Electron microscope (FE-SEM), Fourier Transformation Infra-Red (FTIR) Spectroscopy and sessile drop test instruments, respectively. The experiment was found that using hydrothermal treatments through pressure boiled method led to a removal of binding materials, such as a wax, hemicellulose and lignin, and enhancement the hydrophilic properties of sorghum fibres.

Abstract: Bioplastic composites based on carboxymethyl cellulose (CMC) and urea have been successfully synthesised at various amount of zeolites. Urea inclusion into the bioplastics was supposed to result in nitrogen slow-release composites. The bioplastic composites were prepared by solvent casting the precursor gel containing 0.5 % (w/w) urea in CMC in the petri dishes. The zeolites content was varied at 0.1, 0.5, 1.0, 2.0, and 3.0 % (w/w to CMC). It showed that the addition of zeolites to the bioplastic composites up to 0.5% increased their tensile strength. More addition of zeolites decreased the strain of the bioplastic composite. It could be due to the formation of hydrogen bonds between CMC and zeolites. The amount of urea absorbed in the bioplastics increased as the amount of zeolites increases. It is possibly to be due to the strong interaction between urea and zeolites. The ammonium ions may interact with interchangeable cations in the zeolite. This interaction will also extend the time for the bioplastics to biodegrade. The presence of zeolites in the CMC polymer chains is useful to give nitrogen slow-release composites.