Effect Of Cellulose Fibers Research Articles

The Effect of Cellulose Fiber on the Bending Strength of Autoclaved Aerated Concrete

Autoclaved aerated concrete is becoming an increasingly popular building material, and for good reason. It is ecological, energy efficient, strong, and durable. Studies show that the production of autoclaved aerated concrete saves 85% of energy compared to the production of heavy concrete. However, the use of steel reinforcement in large-sized aerated concrete products leads to deterioration of thermal insulation properties, corrosion, and destruction of the material. Replacing steel reinforcement with discrete fiber strands can solve this problem. The fiber does not affect the thermal insulation properties, is not prone to corrosion, and can be evenly distributed over the entire volume of the product.

The effect of cellulose fibres in an epoxy adhesive for bonding wooden load-bearing elements

The work deals with the modification of the properties of epoxy adhesive. The modification consists of reinforcing this adhesive with cellulose fibres. In the field of wood glued elements, the current research focuses on the possibility of increasing the ductile behaviour of the epoxy adhesive, which would significantly increase the ability of the adhesive to transfer the stresses induced by the volumetric changes of the wood adherend. For this purpose, the adhesive was modified with fibres having a reinforcing character, which may include cellulose fibres. Due to the epoxy resin’s non-polar nature and the cellulose fibre's hydrophilic nature, which inhibits the fibre's homogeneous dispersion, the fibres have been modified with silanes. This paper describes the effect of adhesive modification by determination of tensile and shear strength at different amounts of filling and different types of silane pre-treatment of cellulose fibres. The optimum filling amount can be considered as 1.0% filling of nanofibrillated cellulose (NFC) with epoxy-functional silane pre-treatment.

Effect of Cellulose Fiber from Coconut Coir as Filler For Dental Flowable Composite

The composite restorations in posterior teeth have recently received an increasing interest due to the improvement of their physical and mechanical properties. However, compositing by the most common polymerization procedure tends to deform the tooth structure that may cause some damage in the marginal seal due to the imperfect interfacial attachment. Several techniques have been used to overcome this problem, one of them is using a flowable composites on the bottom of the cavity as the first layer. The purpose of this study is to develop fiber-reinforced composite (FRC) material made of coir fiber (Cocos nucifera) with matrix (Bis-GMA, TEGDMA, DGEBA, and camphorquinone). Cellulose fiber was formed by an anti-solvent method from an aqueous NaOH-urea cellulose solution dropped into ethanol-water mixture. The resulting cellulose fibers were then mixed with the matrix using a magnetic stirrer. The composition of nanocellulose in the matrix was varied 10:90 and their characteristics were compared with the commercial nanofiller composite (Z 350 and 3M) as control. The sample was tested for cross-linked using a scanning electron microscope (SEM) and Fourier transform infrared (FTIR). The morphology of nanocellulose look like a fiber as cross-linked with matrix. Therefore, the formation of a crosslink bond between cellulose and matrix C-O-C with a new wavenumber in 890 cm-1. The nanocellulose composite also form fibers that binds the matrix, while flowable composites from manufacturers from fibers and particulates. From this experimental method it can be suggested coconut fiber has high potential as raw material to be filler in a dental flowable composite.

Understanding the Effects of Cellulose Fibers from Various Pre-Treated Barley Straw on Properties of Aerogels

Understanding the Effects of Cellulose Fibers from Various Pre-Treated Barley Straw on Properties of Aerogels

Experimental study on durability of fiber reinforced concrete: Effect of cellulose fiber, polyvinyl alcohol fiber and polyolefin fiber

The durability of concrete reinforced by cellulose fiber (CTF), polyvinyl alcohol fiber (PF) and polyolefin fiber (VS) is comprehensively studied in this paper. Relevant durability tests are conducted to explore the effect of different fiber types and dosages on durability performance demonstrated in the resistance to drying shrinkage, water permeability, crack, carbonization and chloride ion penetration. Besides single fiber reinforced concrete, synergistic effect of hybrid fibers on durability is also studied, and the service life of fiber reinforced concrete in carbonization environment and chloride ion corrosive environment is further predicted. In addition, the structure of fiber reinforced concrete is analyzed from the micro perspective by using the optical and electron microscope. The results showed that: (1) The addition of CTF can effectively enhance the all five aspects of durability performance, including the resistance to drying shrinkage, water permeability, crack, carbonization and chloride ion penetration. The addition of PF can enhance the durability properties except for chloride ion penetration resistance. Generally, though with few exceptions, the increased dosage of CTF or PF would improve the strengthening effect on the durability of single fiber reinforced concrete. The addition of VS can either enhance or weaken the above five aspects of durability properties, and its effect varies much with the fiber dosage. (2) Hybrid fiber is found to have a positive synergistic effect and enhance the above five aspects of durability properties of concrete. The concrete reinforced with the hybrid fiber combination of 1.2 kg/m3 CTF, 2.0 kg/m3 PF and 2.0 kg/m3 VS may achieve the optimal durability properties. (3) CTF, PF and VS, especially their hybrid combinations, are found to effectively prolong the service life of concrete structure in the carbonization and chloride ion corrosive environment. The research findings obtained in this paper can supplement the study on the durability of fiber reinforced concrete, and provide suggestions for suitable fiber type and dosage selection in actual engineering designs of fiber reinforced concrete.

Dielectric properties and thermal stability of cellulose high-density polyethylene bio-based composites

The project aims to develop cellulose in new biocomposites to produce dielectric materials based on thermoplastic matrices. Cellulose fibers bring multiple advantages to thermoplastic matrices in mechanical, physicochemical, thermal, and dielectric properties. Although these biocomposites are known for their advanced mechanical properties, only a few studies investigated their dielectric behavior and the effect of cellulose fibers on these properties. The bio-based composites must have better dielectric properties and excellent ductility to use as insulators in electrical cables. Thus, we investigated the dielectric properties (dielectric constant (ε’), loss factor (ε’’), conductivity (σ) and resistivity (ρ)) of high-density polyethylene (HDPE) and cellulose fibers composites. Results prove that the addition of cellulosic fibers increased the dielectric constant, the loss factor, and the conductivity of the materials compared to the neat polymer. Composites with 50 wt% fiber content showed the highest values. Therefore, the volume resistivity of all the composites studied decreased with frequency and fiber content. In addition, the reinforced polymer exhibited an intermediate thermal behavior between the polymer and the fibers. Thus, they are thermally stable materials up to 320 °C.

Effects of cellulose fibers on the properties of asphalt mixtures

• Mechanical properties were more sensitive to CF addition methods than volumetric. • CF orientation and distribution may affect the variation in measured properties. • No unique CF-asphalt mixture met all the required properties. • The determination of optimum CF content was inconclusive. Various types of additives have been used in asphalt pavement industry to improve the performance. Among these additives, fibers have received increasing attention to achieve the desired improvement. This investigation aims to evaluate the effect of applying dry and wet methods separately to introduce the cellulose fibers (CF) into the local hot mix asphalt (HMA). The evaluation was carried out by measuring the volumetric and mechanical proprieties of conventional (control) and CF-asphalt mixtures. This study also aims to examine the possibility of using the cellulose fiber as a sustainable material in the local asphalt pavement industry. The effect of variations in cellulose fibers content; 2.5%, 5.0%, 7.5%, and 10.0% by the weight of asphalt cement, aggregate source (Al-Nibaay and Al-Suddor aggregates), and two methods (wet and dry) for adding cellulose fibers to asphalt mixtures are evaluated. Marshall methodology and indirect tensile strength test (ITS) were applied to investigate the effects of these variables. The results of this study showed that the difference in mechanical properties of the fiber-reinforced asphalt mixtures was more sensitive to CF application methods in these mixtures than the difference in volumetric properties. In addition, the wet method improved most properties of Al-Nibaay aggregate asphalt mixtures while the dry method improved most properties of Al-Suddor aggregate asphalt mixtures. Determination of optimum CF content was found inconclusive due to the wide variation in the measured properties. CF can be recommended as a promising sustainable additive to improve the properties of local asphalt pavement. However, further investigation remains necessary to precisely determine the optimum CF content in parallel with the optimum asphalt content and it is also important to assess the resistance of CF-asphalt mixtures to moisture damage and aging.

Experimental study on mechanical properties of fiber reinforced concrete: Effect of cellulose fiber, polyvinyl alcohol fiber and polyolefin fiber

Mechanical properties of concrete reinforced with cellulose fiber (CTF), polyvinyl alcohol fiber (PF) and polyolefin fiber suitable for various spray (VS) are experimentally studied. The individual impact of single fiber as well as synergistic effect of hybrid fiber on axial compressive strength, splitting tensile strength and shear strength of concrete are investigated. Microstructures of fiber reinforced concrete specimen as well as its stress–strain relationship is also observed. The results show that CTF alone enhances axial compressive strength of concrete but weakens splitting tensile strength; VS weakens splitting tensile strength as well but has little impact on the other two strength; PF has a negative effect on all the three mechanical strength. Synergistic effect of hybrid fiber varies with dosage, and only with the appropriate fiber dosage can hybrid fiber has positive synergistic effect on mechanical properties. 1.5 kg/m3 cellulose fiber with 1.0 kg/m3 polyvinyl alcohol fiber is found to be optimal combination of CTF-PF hybrid fiber to achieve the best synergistic effect. Practical implications of CTF, PF and VS are also put forward.

Influence of cellulose pulp on the hydration followed by fast carbonation of MgO-based binders

This study aims at assessing the potential use of cellulose pulp in MgO-water slurries with potential for precast composites. These systems for composites applications envisage encapsulating CO2 when exposed to fast carbonation. The effect of cellulose fibers was evaluated on samples after the drainage of MgO-cellulose-water slurries. Different cellulose mass fractions were added into MgO-water suspensions – up to 30 wt% – to study the MgO hydration during the first 96 h. Afterward, the carbonation of the hydrated products for 6 and 12 h was evaluated. The addition of cellulose, after hydration, increases the sample porosity, where Mg(OH)2 is the main crystalline phase and only minor traces of unreacted MgO are found. MgO-H2O systems after hydration do not present any binding capacity given the low density and high apparent porosity of the clusters. However, XRD and TG analyses show that exposing samples to a rich CO2 environment promotes the formation of nesquehonite (MgCO3·3H20), which significantly reduces the porosity induced by the cellulose hygroscopy. This reduction in porosity is greater for samples with cellulose fibers because of the greater content of nesquehonite produced in samples with cellulose. Besides, cellulose fibers are covered with nesquehonite nanocrystals after carbonation. By adding cellulose to water-MgO suspensions yields lighter products with promising potential for fiber-cement applications. Moreover, the addition of cellulose contributes to the encapsulation of CO2 in building materials through the Mg(OH)2 carbonation.

Effect of cellulose fiber from sorghum bagasse on the mechanical properties and biodegradability of polylactic acid

Synthesis of biocomposites using polylactic acid (PLA) as the matrix and cellulose fiber from sorghum bagasse as the reinforcement agent has been carried out in this study. The objective was to improve the mechanical properties and biodegradability of PLA. In this study, cellulose fiber has been extracted from sorghum bagasse. Micro and nano-sized cellulose fiber was then produced by hydrolysis using sulfuric acid. Biocomposite was then made by casting film method using acetone as the solvent. Based on mechanical test, nanocellulose fiber gives better results on mechanical properties. Moreover, the tensile modulus and biodegradability of PLA were increase with the increasing of nanocellulose fiber concentration. Based on results, the addition of 2.5% nanocellulose fiber, improved the maximum strain from 5.19% to 11.59%. Otherwise, the best biodegradability of biocomposite was achieved on the addition of 15% nanocellulose fiber.

Improving properties of thermoplastic starch films by incorporating active extracts and cellulose fibres isolated from rice or coffee husk

Abstract Hydrothermal (60 min, 180 °C) extracts and cellulose fibres from coffee and rice husks were obtained to be incorporated into corn starch films, in order to improve the film functional properties as food packaging material and confer them active properties. Extracts exhibited antioxidant properties (EC50: 5.37–5.29 mg extract solids/mg DPPH) and antibacterial activity against Listeria innocua and Escheriquia coli (MIC values: 35–45 and 34–35 mg extract solids/mL, respectively). The active extracts improved tensile properties of the starch films; elastic modulus increased by about 350% and films become less stretchable. The cellulosic fibres from both residues were more effective as reinforcing agents in films containing extract solids than in net starch films. Extracts also provoked 30% reduction in the WVP of starch films and 50–85 % reduction in the oxygen permeability, depending on their amount in the films, but no effect of cellulose fibres was observed on barrier properties.

The Effect of Cellulose Fibers on the Formation of Petroleum-Based and Bio-Based Polyurethane Foams

We report on the effect of cellulose fibers on the formation of petroleum-based and bio-based polyurethane foams. The fabricated polyurethane foams (PUF) were done by reacting isocyanate with petroleum-based polyol and epoxidized soybean oil (ESBO)-based polyols via hand mixing. The addition of cellulose fibers extracted from pineapple (Ananas comosus) leaf was done to enhance the properties of the fabricated PUF. Experimental results revealed that surface morphology of the fabricated polyurethane foams with addition of cellulose fibers remain the well-defined cell structures as shown in the scanning electron micrographs although few cell ruptures were observed. Likewise, the presence of the vibrational modes of the NCO and OH were confirmed in the Fourier transform infrared (FTIR) spectra suggesting that successful formation of polyurethane foams takes place. The thermogravimetric results revealed that much higher thermal stability for the 100% ESBO-based PUF with cellulose fibers due to the presence of cellulose and triglycerides in the ESBO-based polyols which both degrades at higher temperature. This suggest that 100% ESBO-based PUF with cellulose fiber exhibit higher thermal stability provides promising application for thermal insulations.

Effect of cellulose fiber from sago waste on properties of starch-based films

An increasing interest in developing biodegradable film using natural biopolymers such as polysaccharides is due to concerns on environmental problems caused by non-biodegradable petroleum-based materials. Though the film exhibits low mechanical properties, it can be improved by adding reinforcing agent, for instance, cellulose fiber. The objective of this study is to investigate the effect of adding cellulose fibers extracted from sago waste on the mechanical and thermal properties of sago starch-based films. Cellulose fibers extracted from sago waste showed reuction in size with cleaner surface as shown in FESEM micrographs. Thermal stability also improved indicated that the hemicelluloses and lignin were eliminated. Films were prepared by solution casting with 4 % sago starch and 3 % cellulose (from starch). These films were characterized using several techniques ie. tensile, x-ray diffractometry, TGA analysis, FESEM analysis and hazemeter. The films produced were highly transparent while film reinforced with cellulose fiber was more crystalline. The addition of fibers increased the tensile strength from 38.66 MPa to 40.70 MPa and Young’s Modulus from 1710 MPa to 1713 MPa. The elongation at break also increased from 3.85 % to 4.62 %. On the other hand, the incorporation of cellulose fibers increased the thermal stability of the film. FE-SEM micrographs of the films showed homogenous distribution of the cellulose fibers. The inclusion of cellulose fiber has successfully increased the properties of the sago starch-based film.

Study on the Effect of Cellulose Fiber on the Crack Resistance of High Performance Concrete

Combining the South-to-North Water Diversion Middle Route Project, the effect of cellulose fiber on the mechanical property, ultimate tensile value, compressive elasticity modulus, durability and crack resistance property of high performance concrete was studied. The test results show that mixing with the cellulose fiber in concrete has less effect on the compressive strength, but can improve the splitting tensile strength, the axial tensile strength and ultimate tensile value of concrete, extend the cracking time of concrete, reduce the crack width and the cracking area of concrete and improve the crack resistance of concrete.

Fabrication of water-repellent cellulose fiber coated with magnetic nanoparticles under supercritical carbon dioxide

Hematite nanoparticle-coated magnetic composite fiber was prepared in supercritical carbon dioxide (scCO2). With the help of scCO2, cellulose did not need to be dissolved and regenerated and it could be in any form (e.g., cotton wool, filter paper, textile, etc.). The penetrating and swelling effect of scCO2, the slowing reaction rate of weak alkalis, and the template effect of cellulose fibers were discovered to be the key factors for the fabrication of ordered cellulose/Fe2O3 composite fibers. The structures of the composite fibers as well as the layers of Fe2O3 particles were characterized by means of scanning/transmission electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, and Raman investigation. It was found that α-Fe2O3 granules which ranged from 30 to 85 nm with average diameter around 55 nm would be generated on the surface of cellulose fibers via potassium acetate, while irregular square prisms (ranged from 200 to 600 nm) which were composed of smaller nanoparticles (~10 nm) would be fabricated via urea. And, the obtained composite was highly water repellent with superparamagnetic or ferromagnetic properties.

Effects of cellulose fibers on the physical and chemical properties of glass ionomer dental restorative materials

A dental glass ionomer cement (GIC) was modified with cellulosic fibers. The microstructural analysis and physicochemical properties were evaluated in four groups: GIC (control) and GIC modified with different concentrations of fibers, GICMF1, GICMF2 and GICMF3. Within clinically acceptable limits, composites showed capacity of water absorption and solubility in water similar to GIC and no signs of disintegration were observed. GICMF2 provided greater resistance to compression, wear and adhesion, however it had no effect on the diametral tensile strength. Morphological and chemical element analyses of GICMF2 showed the formation of a new and stable composite with interaction between fiber/ionomer matrix/load particles.

Effect of cellulose fi bers on morphology and pure water permeation of PSf membranes

Chemical and physical changes are necessary to improve the transport properties of polymeric membranes. Cellulose fiber pulp from Pinus taeda was processed in knives and balls mills in order to reduce the dimensions of the fibers for later application in polysulfone (PSf) membranes. By adding cellulosic fibers in PSf membranes, a composite membrane with improved morphological properties, permeate flux and good resistance to pressure was obtained. The fibers as well as the PSf and PSf/cellulose fibers membranes were morphologically characterized by scanning electron microscopy. Tests of pure water permeate flux were performed with pressure up to 20 bar. The addition of 0.2% (wt) of cellulose fibers in the formation of composite membranes resulted in the elimination of macrovoids, causing an increase in pure water flux (50% ±10) when pressure was risen.

Effect of cellulose fibers on the crystallinity and mechanical properties of starch-based films at different relative humidity values

The objective of this study was to investigate the effect of the addition of cellulose fibers on the mechanical and physicochemical properties of starch-based films plasticized with glycerol. Film samples were prepared from solutions with 3% of cassava starch, with the addition of 0, 0.10, 0.30 and 0.50 g of fibers/g of starch. The mechanical properties of samples conditioned at different relative humidity (RH) values were determined through tensile and stress relaxation tests. SEM micrographs of the films showed a homogeneous and random distribution of the cellulose fibers, without pores or cracks. Films with fibers were more crystalline and had higher tensile strength and rigidity, but lower elongation capacity. On the other hand, addition of cellulose fibers increased the stability of starch-based films subjected to RH variations, solving a classical problem encountered with this kind of film. Thus, the addition of cellulose fibers to starch-based films is an effective way to prepare stronger and more stable films.

Effects of cellulose fibers in polypropylene composites

AbstractA systematic study of the effect of surface pretreatment of cellulosic fibers and the processing time and temperature on the mechanical properties of the cellulose‐containing polypropylene was undertaken. Using non‐treated fibers, the elastic modulus increased gradually with the cellulose content, typically doubling its value at 30 phr fiber content. Treatment of fibers with coupling agent improves significantly the interfacial adhesion and therefore the mechanical properties of composite. Scanning electron micrographs reveal that the shear stress is sufficiently high to break and delaminate the cellulosic fibers. Addition of maleic anhydride modified polypropylene also improves the properties of resulting composites.