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Ouajai, Sirisart, Peerachai Ruangwilairat, Kitti Ongwongsakul, Thanawadee Leejarkpai i Robert A. Shanks. "Morphology and Structure of Modified Oil Palm Empty Fruit Bunch Cellulose Fibre". Advanced Materials Research 93-94 (styczeń 2010): 607–10. http://dx.doi.org/10.4028/www.scientific.net/amr.93-94.607.
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Oil palm empty fruit bunch (OPEFB) cellulose fibre has been widely used as a reinforcing filler in polymer composites. Surface modification of OPEFB fibre was aimed enhancing inter-phase adhesion with a poly(lactic acid) matrix. In this study, the OPEFB fibres were pre-treated in a sodium hydroxide solution. Surface compositions and thermal stability of the fibres were studied using ATR-FTIR and TGA techniques, respectively. The pre-treatment resulted in the removal of non-cellulosic components leaving purer fibres. In addition, an acetylation of OPEFB cellulose fibres by acetic anhydride was conducted under solvent free condition at room temperature (30 °C). The acetylation reaction was catalyzed by iodine. The degree of substitution monitored by solid state 13C NMR depended upon reaction time and molar ratio of OPEFB cellulose and acetic anhydride. Crystalline structure and morphology of the partial acetylated fibres were investigated using WAXD and SEM, respectively.
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Cordin, Michael, i Thomas Bechtold. "Physical properties of lyocell-reinforced polypropylene composites from intermingled fibre with varying fibre volume fractions". Journal of Thermoplastic Composite Materials 31, nr 8 (19.10.2017): 1029–41. http://dx.doi.org/10.1177/0892705717734594.
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Polypropylene (PP)-cellulose fibre blends exhibit substantial potential for the production of high-performance textile fibre–reinforced composites. The production of reinforced parts from PP-cellulose composites through thermal shaping of intermingled fibre blends is a strategy to form parts which exhibit superior mechanical properties. In this study, the use of intermingled fibre slivers with different ratios of lyocell fibres (CLY) and PP fibres as raw materials for thermally formed composites was investigated. Such a concept will maximize the interface between the reinforcement fibres and polymer matrix. The cellulose fibres remain oriented along the direction in which the drawing process was performed, which forms the basis for tailored fibre placement in technical production. Because of good surface contact between the cellulose fibre surface and PP matrix, no special coupling agents were required to improve the interfacial adhesion between the two different polymers. The share of CLY and PP fibres in the composite varied from 50% w/w CLY content, up to 70% w/w CLY. Besides analysis of the mechanical properties, such as tensile strength and E-modulus, attention was directed towards moisture sorption of the composites. The rate of sorption and amount of water bound in the composite were found to be dependent on the cellulose fibre content. Composites with a higher CLY content exhibited a more rapid and higher moisture uptake. In water saturated state, the ultimate tensile strength of composites reduced from 160 MPa to 90 MPa, which is an indicator for a reduced adhesion between the CLY surface and PP matrix. The results indicate the potential of the intermingled fibre concept blend for the efficient manufacturing of composite parts.
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Sobczak, L., A. Limper, H. Keuter, K. Fischer i A. Haider. "Polypropylene-cellulose Innovative Compounding Technology". Polymers from Renewable Resources 3, nr 1 (luty 2012): 27–32. http://dx.doi.org/10.1177/204124791200300103.
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Lightweight construction and recyclability are essential factors when it comes to meeting environmental targets. Natural fibre-reinforced composites (NFCs) have an important role to play here. The density of natural fibre materials is up to 50% lower than that of the reinforcing fibres traditionally used for plastics, such as glass fibres, and as well as being fully recyclable the composites offer 100% thermal energy recovery.
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Sumithra, Murugesan, i Gayathri Murugan. "Extraction and characterization of natural fibres form Elettaria Cardamomum". Tekstilna industrija 69, nr 2 (2021): 30–33. http://dx.doi.org/10.5937/tekstind2102030s.
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Natural fibres are one of the good alternative sources for replacing synthetic fibres and reinforcing polymer matrices because of their eco-friendly nature. The present study was undertaken to investigate the fibres extract from Elettaria Cardamomum plant. The extracted Elettaria Cardamomum fibre was treated with NaOH for softening. Natural cellulose fibres extracted from Elettaria Cardamomum stems (ECS) have been characterized for their chemical composition and physical properties.The chemical composition of Elettaria Cardamomumstems (ECS) fi bres is, cellulose 60.44%, lignin 25.25%, wax 0.53%, ash 5.45%. Regarding physical properties of the fibres, single fibre strength was evaluated and the result was compared with cotton fibre and linen fibre.
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Stevulova, Nadezda, Viola Hospodarova, Vojtech Vaclavik, Tomas Dvorsky i Tomas Danek. "Characterization of cement composites based on recycled cellulosic waste paper fibres". Open Engineering 8, nr 1 (10.11.2018): 363–67. http://dx.doi.org/10.1515/eng-2018-0046.
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AbstractNowadays, there is paying an attention to the utilization of natural, renewable and biodegradable resources of raw materials of lignocellulosic character, residues from agricultural crops and wood processing as well as waste from papermaking industry in building composite materials preparing. Also recycled fibres coming from waste paper are considered as valuable material. The objective of this study is to utilize these recycled cellulosic fibres into cement composites and characterise their impact on resulting physical and mechanical properties of fresh and hardened cement composites. Manufactured cement composites contained 0.2%, 0.3% and 0.5% addition of cellulosic fibres. In fresh fibre cement mixtures reduction in workability with increasing amount of cellulose fibres was noticed. Density as well as compressive and flexural strength of 28 and 90 days hardened fibre cement composites was tested. Distribution of cellulosic fibres with 0.5% addition in hardened fibre cement composites was also observed. The results of density determination of 28 and 90 days hardened fibre cement composites showed reduction in their values related to weight lighter concretes. Compressive strengths of fibre cement composites have shown decreasing character with increasing added amount of cellulosic fibres into the mixture up to 0.5%. Maximal decrease in compressive strength values was observed in composites containing 0.5% of cellulosic fibres. However, obtained strength parameter values of hardened composites had satisfying results for their application in construction as non-load bearing building material.
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Abdullah, ABM, Maruf Abony, MT Islam, MS Hasan, MAK Oyon i Md Bokhtiar Rahman. "Extraction and Proximate Study of Sansevieria Trifasciata L. As Fibre Source for Textile and Other Uses". Journal of the Asiatic Society of Bangladesh, Science 46, nr 2 (29.06.2021): 155–62. http://dx.doi.org/10.3329/jasbs.v46i2.54411.
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Natural fibres are getting importance for their sustainable development in their uses in mitigation of climate change and ecological balance. A fibre extraction retting method is formulated and proximate chemical composition and various physical properties such as tensile strength, elongation, diameter along with fibre, cellulose, lignin and ash content were determined. This preliminary observation indicates its potential to be used as a source of fibre for textile and non-textile uses such as woven, nonwoven, composite, blanded and a good source of α-cellulose, microcrystalline cellulose, nano-cellulose and lignin-based products.
Asiat. Soc. Bangladesh, Sci. 46(2): 155-162, December 2020
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Ardanuy, Mònica, Marcelo Antunes i Jose Ignacio Velasco. "Preparation and Characterization of Cellulosic Fibre-Reinforced Polypropylene Foams". Advanced Materials Research 123-125 (sierpień 2010): 1183–86. http://dx.doi.org/10.4028/www.scientific.net/amr.123-125.1183.
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The preparation and characterization of cellulosic fibre-reinforced polypropylene composite foams is presented. The cellulose fibres were isolated from a barley straw obtained from local sources. They were compounded with the polymer in the melt state to obtain composites with nominal concentrations of 10 and 20% by weight. After compression-moulding the composite samples were foamed in a high-pressure batch-process employing CO2 as foaming agent. The effects of the fibre loading on the basics characteristics of the foams was investigated.
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Schmidt, Vivian Consuelo Reolon, i João Borges Laurindo. "Characterization of foams obtained from cassava starch, cellulose fibres and dolomitic limestone by a thermopressing process". Brazilian Archives of Biology and Technology 53, nr 1 (luty 2010): 185–92. http://dx.doi.org/10.1590/s1516-89132010000100023.
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Cassava starch, dolomitic limestone and eucalypt cellulose fibres were used to prepare foam trays that could be used to pack foodstuffs. The influence of the cellulose fibre concentration in the composite formulation was investigated using 5, 10, 15, 20, 30 and 40% of fibres. The results indicated that an increase in cellulose fibre concentration promoted a decrease in density and tensile strength of the foam samples. The tensile strength at break for foam trays containing 5% of cellulose fibres was 3.03MPa, whilst the commercial trays of expanded polystyrene used to pack foods in supermarkets presented a tensile strength of 1.49 MPa. The elongation at break of the foam trays obtained in this work varied slightly with increase in cellulose fibre concentration, the values being about 20% lower than the elongation at break observed for commercial foam trays of expanded polystyrene. Thus, the materials developed in this work represented a possible alternative to the use of EPS foam trays for packing dry foods. The trays' properties need to be improved for their use with moist foods.
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Ruan, Yong-Ling. "Rapid cell expansion and cellulose synthesis regulated by plasmodesmata and sugar: insights from the single-celled cotton fibre". Functional Plant Biology 34, nr 1 (2007): 1. http://dx.doi.org/10.1071/fp06234.
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Higher plants comprise mixtures of some 40 different cell types, and this often complicates the interpretation of data obtained at the tissue level. Studies for a given cell type may provide novel insights into the mechanisms underlying defined cellular and developmental processes. In this regard, the cotton fibre represents an excellent single-cell model to study the control of rapid cell elongation and cellulose synthesis. These single cells, initiated from the ovule epidermis at anthesis, typically elongate to ~3–5 cm in the tetraploid species before they switch to intensive secondary cell wall cellulose synthesis. By maturity, more than 94% of fibre weight is cellulose. To unravel the mechanisms of fibre elongation and cellulose synthesis, two hypotheses have been examined: (a) that sucrose degradation and utilisation mediated by sucrose synthase (Sus) may play roles in fibre development and (b) that symplastic isolation of the fibre cells may be required for their rapid elongation. Reverse genetic and biochemical analyses have revealed the critical role that Sus plays in fibre initiation and early elongation. Late in development, plasma-membrane and cell wall association of Sus protein seems to be involved in rapid cellulose synthesis. Cell biology and gene expression studies showed a temporary closure of fibre plasmodesmata (PD), probably due to the deposition of callose, at the rapid phase of elongation. The duration of the PD closure correlates positively with the final fibre length attained. These data support the view that PD closure may be required for fibres to achieve extended elongation. The branching of PD towards the secondary cell wall stage is postulated to function as a molecule sieve for tight control of macromolecule trafficking into fibres to sustain intensive cellulose synthesis.
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Auernhammer, Julia, Tom Keil, Binbin Lin, Jan-Lukas Schäfer, Bai-Xiang Xu, Markus Biesalski i Robert W. Stark. "Mapping humidity-dependent mechanical properties of a single cellulose fibre". Cellulose 28, nr 13 (14.07.2021): 8313–32. http://dx.doi.org/10.1007/s10570-021-04058-4.
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AbstractModelling of single cellulose fibres is usually performed by assuming homogenous properties, such as strength and Young’s modulus, for the whole fibre. Additionally, the inhomogeneity in size and swelling behaviour along the fibre is often disregarded. For better numerical models, a more detailed characterisation of the fibre is required. Herein, we report a method based on atomic force microscopy to map these properties along the fibre. A fibre was mechanically characterised by static colloidal probe AFM measurements along the longitudinal direction of the fibre. Thus, the contact stress and strain at each loading point could be extracted. Stress–strain curves were be obtained along the fibre. Additionally, mechanical properties such as adhesion or dissipation were mapped. Local variations of the effective fibre radius were recorded via confocal laser scanning microscopy. Scanning electron microscopy measurements revealed the local macroscopic fibril orientation and provided an overview of the fibre topography. By combining these data, regions along the fibre with higher adhesion, dissipation, bending ability and strain or differences in the contact stress when increasing the relative humidity could be identified. This combined approach allows for one to obtain a detailed picture of the mechanical properties of single fibres. Graphic abstract
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Pan, Yuan Feng, Hui Ning Xiao i Catherine Beh. "Branched and Responsive Antimicrobial Polymers Based on Modified PVA for Functionalizing of Cellulose Fibres". Advanced Materials Research 652-654 (styczeń 2013): 414–17. http://dx.doi.org/10.4028/www.scientific.net/amr.652-654.414.
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In this work polyvinyl alcohol (PVA) was modified via grafting or coupling with the guanidine-based antimicrobial polymer using epichlorohydrin as a crosslinking agent. The resulting polymer was tested for its charge density and inhibition against E.coli. The modified PVA adsorbed onto cellulose fibres via electrostatic association; thus resulting in the hand-sheets (or paper) with improved antimicrobial activity. As a further extension of this work, the temperature-responsive antimicrobial polymers were prepared based on acetalyzed PVA (APVA) grafted with guanidine-based polymer chains. In conjunction with anionic APVA copolymer (APVA copolymerized with sodium acrylate), the cationic and responsive APVA formed a unique antimicrobial polymer system via layer by layer (LbL) assembly, which could adsorb on fibre surfaces and be incorporated into cellulose fibre networks, leading to the functionalizing of cellulose fibres. The lower critical solution temperature (LCST) of APVA copolymer could be tailored by controlling the degrees of acetalysis (DA) and co-monomer ratios. AFM images obtained to reveal the roughness of the surfaces; while the antimicrobial test proved that cellulose fiber assembled with APVA-based multilayers exhibited excellent antimicrobial activity against E.coli.
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Bentchikou, Mohamed, Salah Hanini, Kamel Silhadi i Amor Guidoum. "Élaboration et étude d'un mortier composite à matrice minérale et fibres cellulosiques : application à l'isolation thermique en bâtiment". Canadian Journal of Civil Engineering 34, nr 1 (1.01.2007): 37–45. http://dx.doi.org/10.1139/l06-149.
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This paper presents an experimental study of the effect of adding recycled cellulose fibres on physical, thermal, and mechanical properties of lightweight concrete composites. Results show an important decrease of density and thermal conductivity with an increase of fibre content. Compression and flexural strength decreased with fibre content, but remained within the standard range for hollow non-load-bearing concrete masonry (ASTM C109/C 109-95) for the maximum fibre content (15%).Key words: mortar composite, mineral matrix, cellulose fibre, thermal conductivity, mechanical strengths.
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Beyene, Dawit, Michael Chae, Jing Dai, Christophe Danumah, Frank Tosto, Abayneh Demesa i David Bressler. "Characterization of Cellulase-Treated Fibers and Resulting Cellulose Nanocrystals Generated through Acid Hydrolysis". Materials 11, nr 8 (24.07.2018): 1272. http://dx.doi.org/10.3390/ma11081272.
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Integrating enzymatic treatment and acid hydrolysis potentially improves the economics of cellulose nanocrystal (CNC) production and demonstrates a sustainable cellulosic ethanol co-generation strategy. In this study, the effect of enzymatic treatment on filter paper and wood pulp fibers, and CNCs generated via subsequent acid hydrolysis were assessed. Characterization was performed using a pulp quality monitoring system, scanning and transmission electron microscopies, dynamic light scattering, X-ray diffraction, and thermogravimetric analysis. Enzymatic treatment partially reduced fiber length, but caused swelling, indicating simultaneous fragmentation and layer erosion. Preferential hydrolysis of less ordered cellulose by cellulases slightly improved the crystallinity index of filter paper fiber from 86% to 88%, though no change was observed for wood pulp fibre. All CNC colloids were stable with zeta potential values below −39 mV and hydrodynamic diameters ranging from 205 to 294 nm. Furthermore, the temperature for the peak rate of CNC thermal degradation was generally not affected by enzymatic treatment. These findings demonstrate that CNCs of comparable quality can be produced from an enzymatically-mediated acid hydrolysis biorefining strategy that co-generates fermentable sugars for biofuel production.
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Sirtori, Cesare R., Michela Triolo, Raffaella Bosisio, Alighiero Bondioli, Laura Calabresi, Viviana De Vergori, Monica Gomaraschi i in. "Hypocholesterolaemic effects of lupin protein and pea protein/fibre combinations in moderately hypercholesterolaemic individuals". British Journal of Nutrition 107, nr 8 (28.10.2011): 1176–83. http://dx.doi.org/10.1017/s0007114511004120.
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The present study was aimed to evaluate the effect of plant proteins (lupin protein or pea protein) and their combinations with soluble fibres (oat fibre or apple pectin) on plasma total and LDL-cholesterol levels. A randomised, double-blind, parallel group design was followed: after a 4-week run-in period, participants were randomised into seven treatment groups, each consisting of twenty-five participants. Each group consumed two bars containing specific protein/fibre combinations: the reference group consumed casein+cellulose; the second and third groups consumed bars containing lupin or pea proteins+cellulose; the fourth and fifth groups consumed bars containing casein and oat fibre or apple pectin; the sixth group and seventh group received bars containing combinations of pea protein and oat fibre or apple pectin, respectively. Bars containing lupin protein+cellulose ( − 116 mg/l, − 4·2 %), casein+apple pectin ( − 152 mg/l, − 5·3 %), pea protein+oat fibre ( − 135 mg/l, − 4·7 %) or pea protein+apple pectin ( − 168 mg/l, − 6·4 %) resulted in significant reductions of total cholesterol levels (P < 0·05), whereas no cholesterol changes were observed in the subjects consuming the bars containing casein+cellulose, casein+oat fibre or pea protein+cellulose. The present study shows the hypocholesterolaemic activity and potential clinical benefits of consuming lupin protein or combinations of pea protein and a soluble fibre, such as oat fibre or apple pectin.
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Ullrich, Julia, Martin Eisenreich, Yvonne Zimmermann, Dominik Mayer, Nina Koehne, Jacqueline F. Tschannett, Amalid Mahmud-Ali i Thomas Bechtold. "Piezo-Sensitive Fabrics from Carbon Black Containing Conductive Cellulose Fibres for Flexible Pressure Sensors". Materials 13, nr 22 (16.11.2020): 5150. http://dx.doi.org/10.3390/ma13225150.
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The design of flexible sensors which can be incorporated in textile structures is of decisive importance for the future development of wearables. In addition to their technical functionality, the materials chosen to construct the sensor should be nontoxic, affordable, and compatible with future recycling. Conductive fibres were produced by incorporation of carbon black into regenerated cellulose fibres. By incorporation of 23 wt.% and 27 wt.% carbon black, the surface resistance of the fibres reduced from 1.3 × 1010 Ω·cm for standard viscose fibres to 2.7 × 103 and 475 Ω·cm, respectively. Fibre tenacity reduced to 30–50% of a standard viscose; however, it was sufficient to allow processing of the material in standard textile operations. A fibre blend of the conductive viscose fibres with polyester fibres was used to produce a needle-punched nonwoven material with piezo-electric properties, which was used as a pressure sensor in the very low pressure range of 400–1000 Pa. The durability of the sensor was demonstrated in repetitive load/relaxation cycles. As a regenerated cellulose fibre, the carbon-black-incorporated cellulose fibre is compatible with standard textile processing operations and, thus, will be of high interest as a functional element in future wearables.
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Ismail, Ika, i Mochamad Chalid. "Perilaku Kristalisasi Polipropilena dengan Penambahan Selulosa Mikrofibril Serat Sorgum sebagai Bio-Based Nucleating Agent". SPECTA Journal of Technology 1, nr 1 (27.11.2019): 37–47. http://dx.doi.org/10.35718/specta.v1i1.74.
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Polypropylene with added Microfibrill Cellulosa as additive materials and filler has been investigated. Polypropylene and sorghum fibre has different interface properties, as the result that the compatibility between both are not good. Therefore, modification process for sorghum fibre is needed, the modification process for sorghum surface are alkalinization and bleaching treatment. Alkalinization process is doing with soaking the sorghum fibre in NaOH solution 2% during 2 hours. Bleaching Process used buffer and NaClO2 during 4 hours. Then, polypropylene and microfibrill cellulose mixed with hot melt mixing method. Characterization for this research is how effect from cellulose in sorghum on crystallization of PP. From DSC analysis showed PP with added microfibrill cellulose 1%wt can increase crystallization temperatures up to 126,510C and crstallization time until 8,26 minutes. And the crystallization process may be accelerated 10 seconds.
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Larsson, P. A., i L. Wågberg. "Towards natural-fibre-based thermoplastic films produced by conventional papermaking". Green Chemistry 18, nr 11 (2016): 3324–33. http://dx.doi.org/10.1039/c5gc03068d.
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Strong and ductile barrier materials based on cellulose are predicted to be of great importance in a sustainable society. Such materials can be achieved by partial conversion of the cellulose of wood fibres to dialcohol cellulose. The chemical modification does not compromise the macroscopic fibre structure and still allows for rapid processing by conventional papermaking.
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Bengtsson, Andreas, Jenny Bengtsson, Carina Olsson, Maria Sedin, Kerstin Jedvert, Hans Theliander i Elisabeth Sjöholm. "Improved yield of carbon fibres from cellulose and kraft lignin". Holzforschung 72, nr 12 (19.12.2018): 1007–16. http://dx.doi.org/10.1515/hf-2018-0028.
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AbstractTo meet the demand for carbon-fibre-reinforced composites in lightweight applications, cost-efficient processing and new raw materials are sought for. Cellulose and kraft lignin are each interesting renewables for this purpose due to their high availability. The molecular order of cellulose is an excellent property, as is the high carbon content of lignin. By co-processing cellulose and lignin, the advantages of these macromolecules are synergistic for producing carbon fibre (CF) of commercial grade in high yields. CFs were prepared from precursor fibres (PFs) made from 70:30 blends of softwood kraft lignin (SW-KL) and cellulose by dry-jet wet spinning with the ionic liquid (IL) 1-ethyl-3-methylimidazolium acetate ([EMIm][OAc]) as a solvent. In focus was the impact of the molecular mass of lignin and the type of cellulose source on the CF yield and properties, while membrane-filtrated kraft lignin and cellulose from dissolving kraft pulp and fully bleached paper-grade SW-KP (kraft pulp) served as sources. Under the investigated conditions, the yield increased from around 22% for CF from neat cellulose to about 40% in the presence of lignin, irrespective of the type of SW-KL. The yield increment was also higher relative to the theoretical one for CF made from blends (69%) compared to those made from neat celluloses (48–51%). No difference in the mechanical properties of the produced CF was observed.
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Müssig, J., i N. Graupner. "Test Methods for Fibre/Matrix Adhesion in Cellulose Fibre-Reinforced Thermoplastic Composite Materials: A Critical Review". Reviews of Adhesion and Adhesives 8, nr 2 (30.06.2020): 68–129. http://dx.doi.org/10.7569/raa.2020.097306.
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Due to the increasing discussion about sustainable and CO2-reduced materials, the demand for cellulose-based fibres as a reinforcing component in thermoplastic composites has increased considerably. Knowledge about the possibilities of modifying fibres for improved adhesion to the plastic matrix is essential in this context. The fibre/matrix adhesion in cellulose fibre-reinforced polymers is of considerable importance for the design of composite materials. Unfortunately, there are no standards for many essential methods to determine fibre/matrix adhesion. In this review article, various methods for measuring the interfacial shear strength between fibres and matrix, as an indirect characterisation of adhesion, are presented. Additionally, a brief overview of different methods for surface modification of cellulose fibres to improve the adhesion to a thermoplastic matrix is given. This review focuses on the fact that the parameters for the production of test specimens as well as the test method itself can vary considerably from study to study. Because of this, the comparison of data from different publications is not always possible. Therefore, in this article, the main influencing factors and differences in the methods are presented and discussed. Based on a systematic review and a clear description and discussion of the methods, the reader is given a broad basis for a better understanding of characteristic values for fibre/matrix adhesion.
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Möhl, Claudia, i Andreas Krombholz. "Impact Resistance Bio Compound". Materials Science Forum 825-826 (lipiec 2015): 1047–54. http://dx.doi.org/10.4028/www.scientific.net/msf.825-826.1047.
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Modified wood fibre reinforced polypropylene composites at a wood fibre content of 50 wt. % are prepared using different types of wood fibres (beech wood refiner fibre, mercerised beech wood refiner fibre, mercerised and bleached beech wood refiner fibre as well as beech wood chips, mercerised beech wood chips, mercerised and bleached beech wood chips) to improve the impact resistance of the final composite. Additionally a beech wood refiner fibre-PP composite as well as a beech wood chip-PP composite are mixed with regenerated cellulosic fibres (5 wt. % and 10 wt. %) to further enhance the impact resistance. To increase the interfacial adhesion with the matrix and to improve the dispersion of particles two different coupling agents with contents from 2 wt. % to 8 wt. % are tested with two wood plastic composites (WPC). One is made of beech wood refiner fibres and the other one is produced from beech wood chips.The present study investigated Charpy impact property of wood fibres reinforced polypropylene as a function of fibre modification, content of regenerated cellulosic fibres and coupling agent.From the results it is observed that beech wood refiner fibre-PP composites show better Charpy impact properties than beech wood chips-PP composites. Charpy impact resistance is improved by mixing regenerated cellulose fibres (RCF) and RCF-PP-granule with beech wood refiner fibres and chips. The maximum increase in impact resistance is two times for refiner fibres and 10 % RCF-PP-granule respectively three and a half times for chips and 10 % RCF-PP-granule. By adding coupling agent Charpy impact resistance is nearly doubled for all wood fibre-PP composites.
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Liitiä, T., S. L. Maunu i B. Hortling. "Solid State NMR Studies on Cellulose Crystallinity in Fines and Bulk Fibres Separated from Refined Kraft Pulp". Holzforschung 54, nr 6 (25.10.2000): 618–24. http://dx.doi.org/10.1515/hf.2000.104.
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Summary Solid state NMR spectroscopy has been used in this work to investigate crystallinity of cellulose in spruce wood before and after kraft pulping and TCF bleaching. Effects of refining of the spruce kraft pulp in water and in weak alkali have been studied by determination of the crystallinity of isolated fines and corresponding bulk fibres in order to find out whether the crystallinity in the fibre surface material and inside the fibre wall differ from each other. Also the possible effect of enzymatic endo-1,4-β-galactanase treatment on the crystallinity of some refined pulps has been investigated. It was found that the Iα crystalline form of cellulose predominates over the Iβ form in native spruce and vice versa in all the pulps studied. In pulping part of the cellulose Iα is converted to the more stable Iβ form mainly by heat. Any measurable changes in the degree of crystallinity or in the relative proportions of different crystalline forms of cellulose could not be seen in pulps after refining, TCF-bleaching or galactanase treatment. However, the degree of crystallinity was found to be considerably lower in the fines compared to the corresponding bulk fibres. Therefore it is suggested that the cellulose crystallinity is lower or the size of crystallites smaller on the fibre surface than inside the fibre wall. Slightly higher contents of lignin and hemicelluloses, mainly xylan and mannan, were also found in the fines compared to the bulk fibres.
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Pang, C., R. Shanks, K. Ing i F. Daver. "Plasticised cellulose acetate-natural fibre composite". World Journal of Engineering 10, nr 5 (1.10.2013): 405–10. http://dx.doi.org/10.1260/1708-5284.10.5.405.
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Due to positive impact on the environment, biodegradable composite materials are of growing interest. This study used cellulose acetate, a derivative of cellulose, as the matrix for its solubility and flexibility. Kenaf composites have been used in furniture, ceiling panels, and fences. The aim is to prepare composites with plasticized cellulose acetate and natural fibre. The kenaf fibres were surface treated to remove impurities, in particular, hemicellulose, wax, and lignin. Chopped kenaf was added to dissolve cellulose acetate and cast on a Petri dish. After solvent has evaporated, the composite was compression moulded. The thermal and mechanical properties of the kenaf cellulose acetate composite were characterised. From thermogravimetry, the composites were shown to be stable until moisture began evaporating. As a hydrophilic material, cellulose is sensitive to moisture. The mechanical properties of the composites were analysed under high humidity. Dynamic mechanical analysis showed that these properties changed slightly with humidity.
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Fahlén, Jesper, i Lennart Salmén. "Ultrastructural changes in a holocellulose pulp revealed by enzymes, thermoporosimetry and atomic force microscopy". Holzforschung 59, nr 6 (1.11.2005): 589–97. http://dx.doi.org/10.1515/hf.2005.096.
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Abstract To increase our knowledge of the ultrastructure within softwood fibres, enzymatic treatment, thermoporosimetry, light microscopy, and atomic force microscopy with image analysis were used to investigate the structure of holocellulose softwood pulp fibres. The size of the average cellulose fibril aggregates and the width of pore and matrix lamellae were found to be uniform across the secondary cell-wall layer in the transverse direction of the wood fibre wall. In holocellulose, these dimensions were very similar to those in the native wood, whereas in kraft pulp the cellulose fibril aggregates were larger and the pore and matrix lamellae broader. These differences between holocellulose and kraft pulp fibres suggest that a high temperature is needed for cellulose fibril aggregation to occur. Neither refining nor drying of the holocellulose pulp changed the cellulose fibril aggregate size. Upon drying and enzymatic treatment, a small decrease in the pore and matrix lamella width was evident throughout the fibre wall. This indicated not only uniform distribution of pores throughout the fibre wall, but also enzymatic accessibility to the entire fibre wall. The holocellulose pulp had a somewhat larger pore volume than the kraft pulp. Refining of the holocellulose pulp led to pore closure, probably due to increased mobility of the fibre wall. The enzymatic treatment revealed that during hydrolysis of one hemicellulose, part of the other was also dissolved, indicating that the two hemicelluloses are to some extent linked to each other in the structure.
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Henriksson, Åsa, i Paul Gatenholm. "Controlled Assembly of Glucuronoxylans onto Cellulose Fibres". Holzforschung 55, nr 5 (19.09.2001): 494–502. http://dx.doi.org/10.1515/hf.2001.081.
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Summary In this study we have shown that cellulose fibres can be coated with regular micron-sized particles by controlling the assembly process of xylans on the cellulose surfaces. When cotton linters were exposed to a 5% water solution of xylan from birchwood at 110°C, 2 h, pH 8, the substrates showed an increase in weight of approximately 6.5%, and visualization by AFM revealed regular particles on the fibre surfaces. The surface modification process was optimized using an experimental design where time, temperature, and pH were varied. The experiments showed that the amount of xylan deposited on the fibres could be varied from 2% up to 20% depending on treatment conditions. The temperature and time were the most important parameters, while pH was not important in the investigated region. The morphology of the deposited xylan layer, as shown by SEM, was dependent on the amount of xylan on the fibre surfaces. At low yield the fibres were coated with a homogenous layer, while at higher yields (20%) regular particles of micron size were identified by AFM analysis. The mechanism of this assembly process of xylan on cellulose fibre surfaces is discussed.
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Vicki., W. V., Taness Santhana Rajah i S. Selvakumar. "Synthesis of cellulose from office waste paper and the effect on mechanical properties of cellulose/kenaf/epoxy composite". MATEC Web of Conferences 189 (2018): 05002. http://dx.doi.org/10.1051/matecconf/201818905002.
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Environmental and open public health aspects have an important and increasing role, especially in the exploration of natural fibers from recycle materials. The aim of this study is to synthesis cellulose from office waste paper and use it as a reinforcement filler to develop biocomposites. Epoxy reinforced kenaf fiber and cellulose composite were prepared in this study using polymer casting technique consisting of grinded kenaf fibre (natural fibre) 5% and epoxy 95% as reinforcement element. Cellulose was synthesized from recycled office papers and used as a filler to prepare cellulose/kenaf reinforced epoxy composite. Effect of cellulose to the mechanical properties of the composite were investigated. Samples were fabricated by weight percentage of 0%, 0.5%, 1.0%, 1.5% and 2.0% of cellulose content. For mechanical properties impact test, Rockwell harness and tensile testings were conducted.
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Chang, Sooyoung, Jaedeok Seo, Seokbin Hong, Duck-Gyu Lee i Wonjung Kim. "Dynamics of liquid imbibition through paper with intra-fibre pores". Journal of Fluid Mechanics 845 (20.04.2018): 36–50. http://dx.doi.org/10.1017/jfm.2018.235.
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We present a combined experimental and theoretical investigation of the dynamics of liquid imbibition through paper. The Washburn equation is widely used to describe the dynamics of capillary flow through paper, but this classical model has limited accuracy, which often makes it difficult to use in developing analytic systems such as paper-based microfluidic devices. We here report that the internal cavity of the cellulose fibres composing paper is significantly responsible for the limited accuracy of the Washburn equation. Our experiments demonstrated that liquid can be absorbed in the internal cavity of the cellulose fibres as well as in the inter-fibre pores formed by the fibre network. We developed a mathematical model for liquid imbibition by considering the flow through the intra-fibre pores based on experimental measurements of the intra-structure of cellulose fibres. The model markedly improves the prediction of the liquid absorption length, compared with the results of the Washburn equation, thus revealing the physics behind the limits of the Washburn equation. This study suggests that the accurate description of capillary imbibition through paper require parameters characterizing the internal pores of the cellulose fibres comprising the paper. Our results not only provide a new insight into porous media flows with different sized pores, but also provide a theoretical background for flow control in paper-based microfluidic systems.
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Pang, Chaowei, Robert Shanks i Fugen Daver. "Cellulose fibre-cellulose acetate hybrid composites with nanosilica". Journal of Polymer Engineering 34, nr 2 (1.04.2014): 141–44. http://dx.doi.org/10.1515/polyeng-2013-0168.
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Abstract Biocomposites incorporating cellulose fibres, a renewable resource, have high modulus and strength and flexibility suitable for structural applications. Solution casting, ultrasonication, and compression moulding methods were used to prepare the specimens. Results show that plasticiser indeed improved the flexibility of the composite and adding fillers further enhanced the performance of the composite.
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Ilyas, R. A., S. M. Sapuan, M. R. Ishak i E. S. Zainudin. "Effect of delignification on the physical, thermal, chemical, and structural properties of sugar palm fibre". BioResources 12, nr 4 (4.10.2017): 8734–54. http://dx.doi.org/10.15376/biores.12.4.8734-8754.
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Eco-friendly composites can be prepared by substituting man-made synthetic fibres with various types of cellulosic fibres. Sugar palm-derived nanocrystalline cellulose is a potential substitute. The most important factor in determining a good nanofiller reinforcement agent that can be used in composites is the character of the nanofiller itself, which is affected during a preliminary treatment. Thus, to gain better nanofiller properties, the delignification (NaClO2 and CH3COOH) and mercerization (NaOH) treatments must be optimized. The main objective of this study was to identify the effects of the delignification and mercerization treatments on sugar palm fibre (SPF). In addition, the characteristics of the SPF for the preparation of the hydrolysis treatment to produce nanocrystalline cellulose (NCC) for reinforcement in polymer composites were examined. Sugar palm cellulose (SPC) was extracted from the SPF, and its structural composition, thermal stability, functional groups, and degree of crystallinity were determined via field emission scanning electron microscopy (FESEM), thermogravimetric analysis (TGA), Fourier transform infrared (FTIR) spectroscopy, and X-ray diffraction (XRD), respectively. The density, moisture content, chemical composition, and structure of the SPC were also analysed.
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Janardhnan, Sreekumar, i Mohini Sain. "Isolation of Cellulose Nanofibers: Effect of Biotreatment on Hydrogen Bonding Network in Wood Fibers". International Journal of Polymer Science 2011 (2011): 1–6. http://dx.doi.org/10.1155/2011/279610.
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The use of cellulose nanofibres as high-strength reinforcement in nano-biocomposites is very enthusiastically being explored due to their biodegradability, renewability, and high specific strength properties. Cellulose, through a regular network of inter- and intramolecular hydrogen bonds, is organized into perfect stereoregular configuration called microfibrils which further aggregate to different levels to form the fibre. Intermolecular hydrogen bonding at various levels, especially at the elementary level, is the major binding force that one need to overcome to reverse engineer these fibres into their microfibrillar level. This paper briefly describes a novel enzymatic fibre pretreatment developed to facilitate the isolation of cellulose microfibrils and explores effectiveness of biotreatment on the intermolecular and intramolecular hydrogen bonding in the fiber. Bleached Kraft Softwood Pulp was treated with a fungus (OS1) isolated from elm tree infected with Dutch elm disease. Cellulose microfibrils were isolated from these treated fibers by high-shear refining. The % yield of nanofibres and their diameter distribution (<50 nm) isolated from the bio-treated fibers indicated a substantial increase compared to those isolated from untreated fibers. FT-IR spectral analysis indicated a reduction in the density of intermolecular and intramolecular hydrogen bonding within the fiber. X-ray spectrometry indicated a reduction in the crystallinity. Hydrogen bond-specific enzyme and its application in the isolation of new generation cellulose nano-fibers can be a huge leap forward in the field of nano-biocomposites.
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Norton, Ruth E. "Dyeing cellulose-fibre paper with fibre-reactive dyes". Paper Conservator 26, nr 1 (styczeń 2002): 37–47. http://dx.doi.org/10.1080/03094227.2002.9638621.
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Ruan, Yong-Ling. "Recent advances in understanding cotton fibre and seed development". Seed Science Research 15, nr 4 (grudzień 2005): 269–80. http://dx.doi.org/10.1079/ssr2005217.
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The unique feature of the seed of tetraploid cotton (Gossypium hirsutum and Gossypium barbadense) is that about 30% of the seed coat epidermal cells develop into cellulose-enriched fibres, while the embryos synthesize oils and proteins. Hence, both the maternal and filial tissues of the cotton seed are of significant economic value. After initiation from the ovule epidermis at or just before anthesis, the single-celled fibres elongate to 2.5–6.0 cm long in the tetraploid species before they switch to intensive secondary cell wall cellulose synthesis. Thus, apart from its agronomic importance, the cotton fibre represents a model single-cell system to study the control of cell differentiation and elongation, carbon partitioning to cellulose synthesis and also the interaction between maternal (fibre) and embryonic tissues in seeds. Over the past decade or so, significant effort has been made to understand the cellular and molecular basis of cotton fibre development and oil biosynthesis in the embryo. Metabolic engineering of the oil biosynthetic pathway in cotton seed has successfully produced healthier and stable oils. A number of candidate genes and cellular processes that potentially regulate various aspects of fibre development have been identified. Further elucidation of the in vivo functions of those candidate genes could significantly deepen our understanding of fibre development and offer potential for improvement of fibre quality through genetic engineering or marker-assisted breeding approaches.
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Arnoul-Jarriault, Benoît, Raphaël Passas, Dominique Lachenal i Christine Chirat. "Characterization of dissolving pulp by fibre swelling in dilute cupriethylenediamine (CUEN) solution in a MorFi analyser". Holzforschung 70, nr 7 (1.07.2016): 611–17. http://dx.doi.org/10.1515/hf-2015-0167.
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Abstract The swelling of dissolving pulps has been investigated by a new method based on the MorfiR analyser, which is measuring the width variation of thousands of fibres in a cupriethylenediamine (CUEN) solution in a few minutes. Pulps from various origins were analysed coming from softwood, birch wood, eucalyptus wood, kraft pulps, sulphite pulps and ECF and TCF bleached pulps, which were modified by several treatments including chemical (cold caustic extraction, hypochlorite) or enzymatic (cellulase) methods. The swelling was much affected by the crystalline form of cellulose and the hemicellulose content but did not depend neither on the cellulose DP nor on the fibre structure (hardwood vs. softwood). The dissolving pulp reactivity in the viscose process was also assessed by swelling in dilute solutions of cupriethylenediamine (CUEN) instead of the Fock’s method.
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Balázs, György L., i Olivér Czoboly. "Fibre Cocktail to Improve Fire Resistance". Key Engineering Materials 711 (wrzesień 2016): 480–87. http://dx.doi.org/10.4028/www.scientific.net/kem.711.480.
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Favourable experience with fibre reinforced concrete (FRC) resulted in its increasing use worldwide. The properties of fibre reinforced concrete are mostly influenced by the type and the amount of fibres. Our experimental study was directed to the possible improvements of the residual flexural strength and the properties of concrete exposed to high temperatures with different fibre cocktails including steel, micro polymer or cellulose fibres. The influence of type and amount of fibres on residual flexural strength in cold state were tested after 300, 500 or 800 °C temperature loading.
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K, Divyashree, Amar Sankar, R. C. Chandni i A. V. Raghu. "DIETARY FIBER IMPORTANCE IN FOOD AND IMPACT ON HEALTH". International Journal of Research -GRANTHAALAYAH 5, nr 4RAST (30.04.2017): 17–21. http://dx.doi.org/10.29121/granthaalayah.v5.i4rast.2017.3297.
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Dietary fibre is a non-digestable part of plant material in the diet which is resistant to enzymatic digestion in humans which includes cellulose, non-cellulosic polysaccharides such as hemicellulose, pectic substances, gums, mucilages and a non-carbohydrate component lignin. The diet rich in fibre such as cereals, nuts, fruits and vegetables have a positive effect on health since their consumption has been related to decreased incidence of several diseases. Higher intakes of dietary fiber are linked to less cardiovascular disease, diabetes, obesity, intestinal cancer, constipation, and other disorders that have serious adverse effects on the health of human beings and also higher intakes of fiber are linked to lower body weights. So improvement of diet with high fiber will help in maintaining good health when consumed in the required amount.
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Bergeret, Anne, i Jean Charles Benezet. "Natural Fibre-Reinforced Biofoams". International Journal of Polymer Science 2011 (2011): 1–14. http://dx.doi.org/10.1155/2011/569871.
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Starches and polylactic acids (PLAs) represent the main biobased and biodegradable polymers with potential industrial availability in the next decades for “bio” foams applications. This paper investigates the improvement of their morphology and properties through processing and materials parameters. Starch foams were obtained by melt extrusion in which water is used as blowing agent. The incorporation of natural fibres (hemp, cellulose, cotton linter, sugarcane, coconut) in the starch foam induced a density reduction up to 33%, a decrease in water absorption, and an increase in mechanical properties according to the fibre content and nature. PLA foams were obtained through single-screw extrusion using of a chemical blowing agent that decomposed at the PLA melting temperature. A void content of 48% for PLA and 25% for cellulose fibre-reinforced PLA foams and an improvement in mechanical properties were achieved. The influence of a fibre surface treatment was investigated for both foams.
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Radosavljevic, Milica, Marija Milasinovic-Seremesic, Dusanka Terzic, Goran Todorovic, Zorica Pajic, Milomir Filipovic, Zeljko Kaitovic i Snezana Mladenovic-Drinic. "Effects of hybrid on maize grain and plant carbohydrates". Genetika 44, nr 3 (2012): 649–59. http://dx.doi.org/10.2298/gensr1203649r.
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Maize is one of the most important naturally renewable carbohydrate raw materials. The basic chemical composition (content of starch, protein, oil, crude fibre and ash) and the content of lignocellulose fibres (content of NDF, ADF, ADL, hemicelullose and cellulose) were determined for grain and the whole maize plant of the seven ZP maize hybrids. The negative very significant correlation between protein and starch content (r=-0.78) and significant correlation between oil and starch content (r=-0.65) was obtained in grain. The hybrid ZP 666 had the highest starch, crude fibre, ADF and cellulose content, high NDF content, the lowest ADL and low protein content in grain. The lowest starch, crude fibre, ADF, cellulose content and the highest protein and oil content in grain was determined in hybrid ZP 158. The hybrid ZP 730 had the highest and hybrid ZP158 the lowest dry matter yield of whole plant, whole plant without ear, ear and yield of digestible dry matter of whole plant. The differences in the contents of NDF, ADF, ADL, hemicelluloses, cellulose and digestibility of the whole maize plant among observed ZP hybrids were 6.21%, 4.01%, 0.79%, 5.65%, 3.88% and 6.79%, respectively. Obtained values for the content of lignocellulose fibres differed significantly among hybrids and were closely related to digestibility.
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Hrabalova, Marta, Manfred Schwanninger, Rupert Wimmer, Adriana Gregorova, Tanja Zimmermann i Norbert Mundigler. "Fibrillation of flax and wheat straw cellulose: Effects on thermal, morphological, and viscoelastic properties of poly(vinylalcohol)/fibre composites". BioResources 6, nr 2 (23.03.2011): 1631–47. http://dx.doi.org/10.15376/biores.6.2.1631-1647.
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Nano-fibrillated cellulose was produced from flax and wheat straw cellulose pulps by high pressure disintegration. The reinforcing potential of both disintegrated nano-celluloses in a polyvinyl-alcohol matrix was evaluated. Disintegration of wheat straw was significantly more time and energy consuming. Disintegration did not lead to distinct changes in the degree of polymerization; however, the fibre diameter reduction was more than a hundredfold, creating a nano-fibrillated cellulose network, as shown through field-emission-scanning electron microscopy. Composite films were prepared from polyvinyl alcohol and filled with nano-fibrillated celluloses up to 40% mass fractions. Nano-fibrillated flax showed better dispersion in the polyvinyl alcohol matrix, compared to nano-fibrillated wheat straw. Dynamic mechanical analysis of composites revealed that the glass transition and rubbery region increased more strongly with included flax nano-fibrils. Intermolecular interactions between cellulose fibrils and polyvinyl alcohol matrix were shown through differential scanning calorimetry and attenuated total reflection-Fourier transform infrared spectroscopy. The selection of appropriate raw cellulose material for high pressure disintegration was an indispensable factor for the processing of nano-fibrillated cellulose, which is essential for the functional optimization of products.
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Panthapulakkal, S., i M. Sain. "Preparation and Characterization of Cellulose Nanofibril Films from Wood Fibre and Their Thermoplastic Polycarbonate Composites". International Journal of Polymer Science 2012 (2012): 1–6. http://dx.doi.org/10.1155/2012/381342.
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The aim of this study was to develop cellulose-nanofibril-film-reinforced polycarbonate composites by compression molding. Nano fibres were prepared from wood pulp fibres by mechanical defibrillation, and diameter distribution of the fibres produced was in the range of 1–100 nm. Nanofibre films were prepared from the nanofibre suspensions and were characterized in terms of strength properties, crystallinity, and thermal properties. Strength and modulus of the nano fibre films prepared were 240 MPa and 11 GPa, respectively. Thermal properties of the sheets demonstrated the suitability of processing fibre sheets at high temperature. Tensile properties of the films subjected to composite-processing conditions demonstrated the thermal stability of the fibre films during the compression molding process. Nanocomposites of different fibre loads were prepared by press-molding nano fibre sheets with different thickness in between polycarbonate sheet at 205°C under pressure. The tensile modulus and strength of the polycarbonate increased with the incorporation of the fibres. The strength of the thermoplastic increased 24% with 10% of the fibres and is increased up to 30% with 18% of the fibres. Tensile modulus of the polycarbonate demonstrated significant enhancement (about 100%).
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Castellano, Jessica, María D. Marrero, Zaida Ortega, Francisco Romero, Antonio N. Benitez i Myriam R. Ventura. "Opuntia spp. Fibre Characterisation to Obtain Sustainable Materials in the Composites Field". Polymers 13, nr 13 (24.06.2021): 2085. http://dx.doi.org/10.3390/polym13132085.
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Some studies have evaluated the use of Opuntia as reinforcement for polymeric matrices, obtaining good results in energy absorption tests and increasing the tensile elastic modulus. However, no studies focusing on the previous characterisation of the fibres and their treatment to improve compatibility with polymeric matrices have been found. This work analyses the chemical composition of Opuntia maxima (OM) and Opuntia dillenii (OD) cladodes and fibre, studying how different treatments influence it. AOAC 2000 methods were used to determine non-structural components and the Van Soest method was used to estimate structural components. Surface characteristics of the samples were also evaluated by Fourier Transform Infrared Spectroscopy (FTIR). Opuntia fibre presented higher cellulose (50–66%) and lignin (6–14%) content and lower hemicellulose (8–13%) content than Opuntia cladodes (9–14% cellulose, 20–50% hemicellulose, 1–4% lignin). Despite the variability of lignocellulosic materials, OD cladodes treated with water and acetic acid achieved an increase in the structural components. Alkaline fibre treatment removed pectin and hemicellulose from the fibre surface, slightly increasing the cellulose content. Future research should evaluate whether the treated Opuntia fibre can improve the mechanical properties of reinforced polymer.
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Tonoli, Gustavo Henrique Denzin, M. N. Belgacem, G. Siqueira, J. Bras, Lourival M. Mendes, F. A. Rocco Lahr i H. Savastano Jr. "Processing Changes of Cement Based Composites Reinforced with Silane and Isocyanate Eucalyptus Modified Fibres". Key Engineering Materials 517 (czerwiec 2012): 437–49. http://dx.doi.org/10.4028/www.scientific.net/kem.517.437.
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Fibre-cement products had been widely used in the world due to their versatility as corrugated and flat roofing materials, cladding panels and water containers presented in large number of building and agriculture applications. The main reason for incorporating fibres into the cement matrix is to improve the toughness, tensile strength, and the cracking deformation characteristics of the resultant composite. One of the drawbacks associated with cellulose fibres in cement application is their dimensional instability in the presence of changing relative humidity. The objective of the present work is to evaluate the effect of surface treatment of eucalyptus cellulose pulp fibres on the processing and dimensional changes of fibre-cement composites. Surface modification of the cellulose pulps was performed with methacryloxypropyltri-methoxysilane (MPTS), aminopropyltri-ethoxysilane (APTS) and n-octadecyl isocyanate, an aliphatic isocyanate (AI), in an attempt to improve their dimensional instability into fibre-cement composites. X-ray photoelectron spectroscopy (XPS) showed the chemical changes occurred at the surface, and contact angle measurements showed the changes in the surface energy. MPTS-and AI-treated fibres presented lower hydrophilic character than untreated fibres, which led to lower water retention values (WRV). APTS increased the water retention value of the pulp and improved the capacity of hydrogen bonding of the fibres. MPTS-and AI-treated fibres led to low final water/cement ratios and reduced volume changes after pressing. MPTS-treated fibres decreased the water and dimensional instability of the fibre-cement composites, while the contrary occurred with APTS-modified and AI-modified fibres.These results are promising and contribute for new strategy to improve processing and stability of natural fibres-reinforced cement products.
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Szabó, László, Sari Imanishi, Naohiro Kawashima, Rina Hoshino, Kenji Takada, Daisuke Hirose, Takayuki Tsukegi, Kazuaki Ninomiya i Kenji Takahashi. "Carbon fibre reinforced cellulose-based polymers: intensifying interfacial adhesion between the fibre and the matrix". RSC Advances 8, nr 40 (2018): 22729–36. http://dx.doi.org/10.1039/c8ra04299c.
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Liitiä, Tiina, Sirkka L. Maunu i Bo Hortling. "Solid State NMR Studies on Inhomogeneous Structure of Fibre Wall in Kraft Pulp". Holzforschung 55, nr 5 (19.09.2001): 503–10. http://dx.doi.org/10.1515/hf.2001.082.
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Summary Solid state NMR spectroscopy was used to analyse the inhomogeneous structure of kraft fibre. Primary fines, isolated from the original kraft pulp, and secondary fines, isolated after refining, were compared with the corresponding long fibres. To fractionate fibre wall surface material, the kraft pulp was refined in stages. After each stage, the secondary fines and long fibres were separated and the long fibres refined again to peel off the surface material. It was found that the crystallinity of cellulose is lower in fines compared with the corresponding long fibres. When the fines fractions were compared with each other, the cellulose crystallinity was observed to increase towards the inner parts of the fibre surface. A very clear gradient was also seen in the amount of extractives, which was highest in the primary fines rich in ray cells. The contents of lignin and some hemicelluloses, mainly xylan and glucomannan, were also higher in fines. Residual lignin isolated from the fines was found to be slightly more condensed than residual lignin from long fibres.
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Lertngim, Anantaya, Manisara Phiriyawirut, Jatuphorn Wootthikanokkhan, Kitti Yuwawech, Weradesh Sangkhun, Pisist Kumnorkaew i Tanyakorn Muangnapoh. "Preparation of Surlyn films reinforced with cellulose nanofibres and feasibility of applying the transparent composite films for organic photovoltaic encapsulation". Royal Society Open Science 4, nr 10 (październik 2017): 170792. http://dx.doi.org/10.1098/rsos.170792.
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This research concerns the development of Surlyn film reinforced with micro-/nanofibrillated celluloses (MFC) for use as an encapsulant in organic photovoltaic (OPV) cells. The aim of this work was to investigate the effects of fibre types and the mixing methods on the structure–properties of the composite films. Three types of cellulose micro/nanofibrils were prepared: the as-received MFC, the dispersed MFC and the esterified MFC. The fibres were mixed with Surlyn via an extrusion process, using two different mixing methods. It was found that the extent of fibre disintegration and tensile modulus of the composite films prepared by the master-batching process was superior to that of the composite system prepared by the direct mixing method. Using the esterified MFC as a reinforcement, compatibility between polymer and the fibre increased, accompanied with the improvement of the percentage elongation of the Surlyn composite film. The percentage of light transmittance of the Surlyn/MFC films was above 88, regardless of the fibre types and fibre concentrations. The water vapour transmission rate of the Surlyn/esterified MFC film was 65% lower than that of the neat Surlyn film. This contributed to the longer lifetime of the OPV encapsulated with the Surlyn/esterified MFC film.
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Wang, Xiaoqing, Haiqing Ren, Bo Zhang, Benhua Fei i Ingo Burgert. "Cell wall structure and formation of maturing fibres of moso bamboo ( Phyllostachys pubescens ) increase buckling resistance". Journal of The Royal Society Interface 9, nr 70 (14.09.2011): 988–96. http://dx.doi.org/10.1098/rsif.2011.0462.
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The mechanical stability of the culms of monocotyledonous bamboos is highly attributed to the proper embedding of the stiff fibre caps of the vascular bundles into the soft parenchymatous matrix. Owing to lack of a vascular cambium, bamboos show no secondary thickening growth that impedes geometrical adaptations to mechanical loads and increases the necessity of structural optimization at the material level. Here, we investigate the fine structure and mechanical properties of fibres within a maturing vascular bundle of moso bamboo, Phyllostachys pubescens , with a high spatial resolution. The fibre cell walls were found to show almost axially oriented cellulose fibrils, and the stiffness and hardness of the central part of the cell wall remained basically consistent for the fibres at different regions across the fibre cap. A stiffness gradient across the fibre cap is developed by differential cell wall thickening which affects tissue density and thereby axial tissue stiffness in the different regions of the cap. The almost axially oriented cellulose fibrils in the fibre walls maximize the longitudinal elastic modulus of the fibres and their lignification increases the transverse rigidity. This is interpreted as a structural and mechanical optimization that contributes to the high buckling resistance of the slender bamboo culms.
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Pöhler, Tiina, Jukka A. Ketoja, Timo Lappalainen, Veli-Matti Luukkainen, Ilkka Nurminen, Panu Lahtinen i Katariina Torvinen. "On the strength improvement of lightweight fibre networks by polymers, fibrils and fines". Cellulose 27, nr 12 (28.05.2020): 6961–76. http://dx.doi.org/10.1007/s10570-020-03263-x.
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Abstract Novel lightweight cellulose fibre materials containing various strength enhancing polymeric and fibrillar components were formed with the help of foam technology. Increasing inter-fibre bond strength and local material density was attempted with unique lignin-containing wood fines (V-fines), cellulose microfibrils (CMF), TEMPO-oxidized cellulose nanofibrils (TCNF), and macromolecules such as cationic starch, polyvinyl alcohol (PVA), and locust bean gum (LBG). The investigated fibres included both long hemp bast fibres and northern bleached softwood Kraft pulp. In the low-density range of 38–52 kg/m3, the compression stress and modulus were highly sensitive to inter-fibre bond properties, the multi-scale features of the fibre network, and the foaming agent employed. Still, the compression-stress behaviour in most cases approached the same theoretical curve, derived earlier by using a mean-field theory to describe the deformation behaviour. At 10% addition level of fine components, the specific compression stress and compression modulus increased in the order of V-fines < CMF < TCNF. A tremendous increase in the compression modulus was obtained with LBG, leading to a material surface that was very hard. In general, the foams made with PVA, which acts both as foaming agent and reinforcing macromolecule, led to better strength than what was obtained with a typical anionic sodium dodecyl sulphate surfactant. Strength could be also improved by refining the softwood pulp. Graphic abstract
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Jahan, M. Sarwar, D. Alam, M. Mostafzur Rahman i MA Quaiyyum. "Isolation and characterization of lignin from okra (Abelmoschus esculentus) fibre and stick". Bangladesh Journal of Scientific and Industrial Research 50, nr 4 (11.12.2015): 257–62. http://dx.doi.org/10.3329/bjsir.v50i4.25834.
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The okra (Abelmoschus esculentus) plant consists of bast fiber and core (stick). The bast fibre of okra plant was characterized with high ?-cellulose (56.7%) and low lignin (12.6%) and stick withlow ?-cellulose (34.3%) and high lignin (25.2%) content. Lignin was isolated from the fiber and stick by acidolytic dioxane method and characterized for elemental analysis, methoxyl analysis and FTIR and 1H-NMR spectroscopy. The C9 formulas for okra stick and fibre lignin were C9H9.61O4.63(OCH3)1.24 and C9H8.61O4.66(OCH3)1.49, respectively. Both of the lignins were of the guaiacyl-syringyl type. The bands of FT-IR spectrum at 1327 cm-1, 1122 cm-1 and 837 cm-1 associated with syringyl unit was higher in okra fibre lignin than in the okra stick lignin. The structural analysis revealed that the average numbers of proton of ?-O-4 (H? & H?) per C9 unit in okra stick and fibre lignin were 1.53 and 1.20, respectively. The ?-O-4 units in these lignins had predominately erythro stereochemistry type.Bangladesh J. Sci. Ind. Res. 50(4), 257-262, 2015
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Ghorani, B., P. Goswami i S. J. Russell. "Parametric Study of Electrospun Cellulose Acetate in Relation to Fibre Diameter". Research Journal of Textile and Apparel 19, nr 4 (1.11.2015): 24–40. http://dx.doi.org/10.1108/rjta-19-04-2015-b003.
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The objective was to identify the main factors and interactions influencing the fibre diameter in the production of electrospun cellulose acetate (CA) webs. A systematic parameter study was completed for producing electrospun CA fibres that were substantially free of bead defects and the effect of different process parameters during electrospinning CA were evaluated in respect of mean fibre diameter. The experiments were planned using factorial designs. Altogether three parameters, each at three levels, were selected for this study. The results indicate that polymer concentration, voltage and flow rate interact so that the magnitude of any change in the mean fibre diameter is dependent upon the level of the other factors. Furthermore, stable electrospinning conditions for CA were confirmed using an acetone: N, N-dimethylacetamide (DMAc) (2:1) solvent system that minimised the presence of structural defects in the web and promoted uniform fibre diameters.
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Kim, Min-Jun, Bum-Sik Lee, Hyeong-Gook Kim, Sang-Woo Kim i Kil-Hee Kim. "Crack Properties of Press Concrete for Varying Types of Fibre Reinforcement". Advanced Composites Letters 26, nr 3 (maj 2017): 096369351702600. http://dx.doi.org/10.1177/096369351702600302.
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This study evaluates the crack control capacity of press concrete with fibre reinforcement used in underground parking lot. The primary test variable is the types of fibre reinforcement. The mock-up specimens are targeted at the floor of an underground parking lot in subjective to a frequent traffic load, and designed to be 4,000mm long and 3,250 mm wide. Cellulose and nylon fibres are used as fibre reinforcement. The test results showed that the fibre reinforcement used in the study effectively controlled the cracks of specimens due to the increased split tensile strength of specimens and the enhanced adhesion performance between fibres and cement mortar.
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Kesavelu, Dr Dhanasekhar, i Dr Nithya Franklyn. "Review on the role and recommendation for dietary fibers in Childhood constipation". International Journal of Medical Science and Clinical Invention 8, nr 01 (27.01.2021): 5214–18. http://dx.doi.org/10.18535/ijmsci/v8i01.06.
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The plant material in the diet that is resistant to enzymatic digestion is defined as “dietary fibre”. The primary ingredients that are classified as dietary fibres are cellulose, hemicellulose, pectic substances, gums, mucilages and lignin etc. Dietary fibre naturally exist in foods that are consumed daily viz.,cereals, fruits, vegetables and nuts. The diets with high content of fibre have shown benefits in multiple areas and systems in maintaining a mileu’-interior. Processing of foods leads to various changes in physical, chemical, enzymatic and thermal treatments, which may affect the composition of total fiber present in the diet.Fibres included in the diet leads to various changes in the qualitative aspects of the food that is processed. Favourable outcomes have been reported in various commodities such as cereals,bread,yoghurt and beverages. The importance and the uses of fibres in diet is an area of constant interest which needs to be explored further and our paper reviews and explains the relation between dietary fibres and their benefits, primarily in children [1]
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Šutka, Anna, Silvija Kukle, Janis Gravitis i Laima Grave. "Characterization of Cellulose Microfibrils Obtained from Hemp". Conference Papers in Materials Science 2013 (10.12.2013): 1–5. http://dx.doi.org/10.1155/2013/171867.
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Microfibrillated cellulose was extracted from hemp fibres using steam explosion pretreatment and high-intensity ultrasonic treatment (HIUS). The acquired results after steam explosion treatment and water and alkali treatments are discussed and interpreted by Fourier transform infrared spectroscopy (FTIR). Scanning electron microscopy (SEM) was used to examine the microstructure of hemp fibres before and after each treatment. A fibre size analyser was used to analyse the dimensions of the untreated and treated cellulose fibrils. SEM observations show that the sizes of the different treated fibrils have a diameter range of several micrometres, but after HIUS treatment fibres are separate from microfibrils, nanofibres, and their agglomerates.