Characterization of new natural cellulosic fiber from kusha grass

The present research work aimed to characterize new natural cellulosic kusha fibers extracted from the kusha grass plants. The physical and chemical properties of kusha fibers such as cellulose content (70.58%), lignin (14.35%), wax content (1.52%), ash content (2.46%), moisture content (8.01%), and density (1.1025 g cc^?1) were identified. An X-ray diffraction of kusha fibers confirms the presence of cellulose with a crystalline index of 55.4%. Fourier transform infrared spectroscopy analysis was carried out to establish the certainty of using them as reinforcement fiber. Thermogravimetric analysis ensures thermal stability up to 357°C which is within the polymerization process temperature.     

Extraction and characterization of alkali-treated red coconut empty fruit bunch fiber

This article discusses the extraction and characterization of new natural fiber extracted from red coconut empty fruit bunch. The physicochemical, mechanical, and thermal properties of alkali-treated red coconut empty fruit bunch fibers (ARCEFBFs) were reported and compared with other natural fibers for the first time. Cellulose content (65.02 wt%), wax (0.32 wt%), density (1.421 g/cc), and tensile strength (1299.49 MPa) were identified in ARCEFBFs. Fourier transform infrared spectroscopy and X-ray diffraction analysis confirmed that ARCEFBFs are rich in cellulose content with crystallinity index of 53.6%. Thermogravimetric analysis revealed that these fibers are thermally stable until 270.48°C.     

Effect of wood sawdust filler on the mechanical properties of Indian mallow fiber yarn mat reinforced with polyester composites

The research article focused on the effect of wood sawdust as secondary filler reinforcement in Indian mallow fiber yarn mat reinforced with polyester composites. Composites were fabricated along the transverse and longitudinal orientation in six different combinations by compression molding machine. The mechanical properties of composites by single and double layer yarn mat with and without wood sawdust filler were evaluated while loading composites specimen on warp and weft direction at the first time in this research paper. The Indian mallow fiber double layer longitudinal orientation yarn mat/wood sawdust filler/polyester composite specimen along the warp direction was found to exhibit optimum mechanical properties compared to other composites. Furthermore, the Indian mallow fiber yarn mat composites were fabricated with helmet and civil construction pipes at first time in this work to replace the synthetic fiber through natural fiber. Scanning electron microscopy was performed to study the morphologies of internal crack and fractured surface of composites.     

Extraction and characterization of new natural lignocellulosic fiber Cyperus pangorei

This research is focused on the study of the physical, chemical, mechanical, and thermal properties of a newly identified natural stem fiber, Cyperus pangorei. The chemical composition of Cyperus pangorei fibers (CPF) such as cellulose, lignin, ash, moisture, and wax contents was evaluated. Besides these, the fiber density was determined and the apparent diameter was measured using an optical microscope. Further, tensile, thermal, XRD, and FT-IR studies were performed to evaluate the suitability of the fiber as a reinforcement. The surface topography of CPF was analyzed using scanning electron microscopy (SEM). Encouraging properties such as increased stiffness, fiber texture, and higher thermal stability suggest the suitability of CPF as reinforcement in polymer matrices.     

Extraction and characterization of lignocellulosic fibers from Luffa cylindrica fruit

The need for recyclable, renewable materials has resulted in an increased use of natural fibers for reinforcing polymers to suit a wide variety of applications. This study is mainly focused on the extraction and characterization of the lignocellulosic fibers derived from the ripened, dried Luffa cylindrica L. fruit. Characterization studies such as Fourier transform infrared spectroscopy, X-ray diffraction, and thermogravimetric analysis are conducted and reported. Composite samples prepared using unsaturated polyester resin show an increasing impact strength on fiber loading. Fractured surface of the composites are examined using scanning electron microscope. Results show the feasibility of fibers for reinforcement in polymers.     

Preparation and adsorption of novel cellulosic fibers modified by β‐cyclodextrin

Novel cellulosic fibers modified by β‐cyclodextrin (CFEC) were prepared for adsorption for heavy metal ions like copper (II) and organic dye like neutral red from their aqueous solutions. The modified cellulosic fibers gave higher copper ion adsorption, and showed copper ion uptake values of 6.24 mg/g at 293°C, as against no adsorption for unmodified cellulosic fibers. Adsorption isotherm model indicated the adsorption of the novel modified fibers for heavy metal ions best fitted for Langmiur model. The adsorption was an exothermic reaction, and the reaction caloric was 6.295 kJ/mol. Copper ions could form a 7:4 complex with β‐cyclodextrin (β‐CD). The novel modified cellulosic fibers could also form inclusion complexes with neutral red via β‐CD molecules. In addition, it was found that the novel modified cellulosic fibers had nearly the same mechanical and thermal properties as the unmodified cellulosic fibers because the modification did not destroy the main chain of cellulose molecules. Copyright © 2008 John Wiley & Sons, Ltd.     

Extraction and characterization of natural cellulosic fiber from Passiflora foetida stem

This article presents a comprehensive characterization study of natural cellulosic fiber extracted from Passiflora foetida vine stem. The chemical composition of the obtained P. foetida fibers (PFFs) comprised high cellulose (77.9 wt%) and low lignin (10.47 wt%) content and had distinctly higher crystallinity (67.36%) of cellulose, which was determined by an X-ray diffractometer. The PFFs exhibited good tensile strength of 248?942 MPa associated with elongation (1.38?4.67%) during tensile testing. Thermogravimetric analysis revealed that the PFFs are thermally stable up to 320°C with kinetic activation energy of 85.46 kJ mol^?1; hence they ensure their suitability as a reinforcing phase in composites for potential applications.     

Characterization of new cellulosic fiber from the stem of Sida rhombifolia

Natural fibers play a vital role in the field of composites mainly due to their environmental friendliness, the nature of their disposal, and low energy requirement for processing. Recently, research ideas have focused on exploration of promising natural fibers with superior mechanical properties. Sida rhombifolia is one such perennial shrub from which high stiffness natural fibers can be extracted. The physico-chemical properties of Sida rhombifolia fibers (SRFs), crystallinity index (56.6%), higher cellulose (75.09 wt.%) content, and lower density (1320.7 kg/m³) were revealed and compared to those properties of other natural fibers.     

Physico-chemical properties of new cellulosic fibers from the bark of Acacia planifrons

Identification of new natural fibers is growing due to their superior properties and the impetus for researchers to develop high-performance composites. This investigation was aimed at understanding the physico-chemical properties of Acacia planifrons fibers (APFs). The crystalline structure of APFs was analyzed by X-ray diffraction, and the crystallinity index (65.38%) was calculated. The chemical functional group of APFs was confirmed by Fourier transform-infrared spectroscopy, the thermal stability measured by thermogravimetric analysis, and surface characterization established by atomic force microscopy. Taken together, all the properties of APFs can play a vital role in establishing APFs as new reinforcement in polymer composites.     

Ecofriendly Biocomposites from Natural fibers: Mechanical and Weathering study

Increasing environmental concerns and depletion of petroleum resources has forced researchers around the globe to find new green materials. In the present research work, a particular interest was focused on the effective use of lignocellulosic natural fibers as reinforcement using polymer resin as a novel matrix. Green composites were prepared using the compression molding technique with different fiber contents. The physicomechanical and thermal characteristics of the different composite samples were investigated as a function of fiber contents. The results obtained suggest that the properties of the polymer matrix are positively affected by the incorporation of natural cellulosic fibers.     

Facile extraction,processing and characterization of biorenewable sisal fibers for multifunctional applications

Synthetic fibers based materials have replaced most of the traditional metallic/ceramic materials for a number of applications owing to their enormous properties such as light weight, specific strength and modulus to name a few. Unfortunately, the traditional synthetic fibers are not desired from the health and environmental point of view. So, in this work, we have carried out the isolation, processing and characterization of cellulosic sisal fibers. These fibers were extracted for the first time by a simple and new unique mechanical extraction technique without affecting the quality of fibers. Subsequently these cellulosic sisal fibers were thoroughly characterized for their physicochemical, microstructure and mechanical properties. These fibers were then converted into fine textured sisal textile yarn made out of 3–6 sisal fibers in continuous operation and used for the preparation of new green materials. Different properties of fine textured sisal textile and the impact of sisal fine textile on the physical, microstructural, thermal and mechanical characteristics of the green materials were studied and discussed in detail.     

A new study on effect of various chemical treatments on Agave Americana fiber for composite reinforcement: Physico-chemical,thermal, mechanical and morphological properties

This research is focused to fundamentally understand the benefits of using Agave Americana C. plant as potential reinforcement in polymeric composites. The fibers were extracted from the external part of the bark of the plant, which grows worldwide in pastures, grasslands, open woodlands, coastal and riparian zones. In order to use the natural fiber as reinforcement it is paramount important to probe their chemical composition, microstructural behavior and mechanical properties. Hence, firstly the extracted fibers were chemically treated with NaOH, stearic acid, benzoyl peroxide and potassium permanganate. The chemical composition in terms of cellulose, hemicellulose, lignin and other waxy substances were determined using a standard TAPPI method. FT-IR technique was used to understand the character of molecular bonds, crystallinity and their correlations with various bonds in fiber structure. The thermal stability was investigated through thermogravimetric and differential scanning calorimetric analysis, and the mechanical characterization was performed by applying standard tensile test. The surface morphology of fibers was examined through scanning electron microscopy (SEM) and finally reliability scrutiny of all the analysis was carried out. The results of chemical modification techniques applied on the surfaces of natural fibers allows to produce superior fibers used to form the novel composite materials for light-weight application.     

Fibers and 3D mesh scaffolds from biodegradable starch-based blends: production and characterization

The aim of this work is the production of fibers from biodegradable polymers to obtain 3D scaffolds for tissue engineering of hard tissues. The scaffolds required for this highly demanding application need to have, as well as the biological and mechanical characteristics, a high degree of porosity with suitable dimensions for cell seeding and proliferation. Furthermore, the open cell porosity should have adequate interconnectivity for a continuous flow of nutrients and outflow of cell metabolic residues as well as to allow cell growth into confluent layers. Blends of corn starch, a natural biodegradable polymer, with other synthetic polymers (poly(ethylene vinyl alcohol), poly(epsilon-caprolactone), poly(lactic acid)) were selected for this work because of their good balance of properties, namely biocompatibility, processability and mechanical properties. Melt spinning was used to produce fibers from all the blends and 3D meshes from one of the starch-poly(lactic acid) blends. The experimental characterization included the evaluation of the tensile mechanical properties and thermal properties of the fibers and the compression stiffness, porosity and degradation behavior of the 3D meshes. Light microscopy picture of 3D meshes.     

Novel polyurethanes from xylan and TDI: Preparation and characterization

Xylan is a hemicellulose, which is found abundantly in nature. In this work, a novel polyurethane was developed involving xylan and tolylene-2,4-diisocyanate (TDI). Polymer synthesis was achieved through conventional heat or microwave-assisted reaction in dimethyl sulfoxide. Because xylan has multiple OH groups on each polymer chain, the TDI/xylan molar ratio had to be adjusted to produce a soluble polymeric product. The reaction products were characterized by ¹³C NMR, FTIR, thermogravimetric analysis, and differential scanning calorimetry. The xylan polyurethane was shown to exhibit improved thermal stability over xylan.     

Preparation of starch-based biocomposites reinforced with mercerized lignocellulosic fibers: Evaluation of their thermal,morphological, mechanical,and biodegradable properties

In the present paper, starch-based biocomposites have been prepared by reinforcing corn starch matrix with mercerized Abelmoschus esculentus lignocellulosic fibers. The effect of fiber content on mechanical properties of composite was investigated and found that tensile strength, compressive strength, and flexural strength at optimum fiber content were 69.1%, 93.7% and 105.1% increased to that of cross-linked corn starch matrix, respectively. The corn starch matrix and its composites were characterized by Fourier transform infrared spectroscopy (FT-IR), Scanning electron microscopy (SEM), X-ray diffraction (XRD) and thermogravimetric (TGA) analysis. The fiber reinforced composites were found to be highly thermal stable as compared to natural corn starch and cross-linked corn starch matrix. Further, water uptake and biodegradation studies of matrix and composites have also been studied.     

Isolation and characterization of nanocrystalline cellulose from flaxseed Hull: A future onco-drug delivery agent

Cellulose is a polysaccharide composed of D-glucopyranose linked by 1,4 β-glycoside bond with three hydroxyl groups. These hydroxyl groups in cellulose have an important role in the compactness of crystalline structure and in determining the physical properties of cellulose. Cellulose in nanometers size range from 10 nm to 350 nm is known as nano cellulose, which has a variety of applications due to the unique properties such as low density, biodegradable, and good mechanical properties. In the present study, we present the isolation of the nano cellulose from flaxseed hull for the first time. The isolated nano cellulose was characterized by techniques such as UV–Vis, FT-IR, BET, XRD SEM, and TEM. The nano cellulose obtained was found to be crystalline in nature with a crystallinity index of 46% and the surface area of 5 cm²/g with excellent thermal stability.     

Reorientation of crystalline and noncrystalline regions in regenerated cellulose fibers and films tested in uniaxial tension

The orientation of molecular chains in regenerated cellulose films and fibers was characterized using in situ wide‐angle X‐ray diffraction and birefringence measurements coupled with tensile tests. Generally, an increase in the degree of preferred orientation in the direction of applied strain was observed during testing. For both types of specimen this relationship was clearly linear, irrespective of whether the volume‐averaged preferred orientation or the orientation in the crystalline and noncrystalline regions was considered. Interestingly, the rate of change in orientation induced by external strain was significantly higher for noncrystalline regions when compared with that of crystalline regions. This difference was more pronounced for cellulose fibers when compared with films. Upon the reversal of straining in cellulose films until zero stress, the degree of orientation diminished in a linear fashion. However, a large part of the orientation, both crystalline and noncrystalline, induced by tensile straining remained permanent and increased further when straining was resumed. © 2007 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 46: 297–304, 2008     

Structural and optical characterization of pyrolytic carbon derived from novolac resin

The structural and optical properties of technologically interesting pyrolytic carbons formed from cured novolac resin and cured novolac/biomass composites were studied by X-Ray Diffraction Analysis (XRD), and Fourier Transform Infrared (FTIR), Raman and Photoluminescence (PL) spectroscopy. Pyrolysis of the cured materials took place at temperatures in the range 400–1000 °C. The most important weight loss, shrinkage and structural changes of pyrolyzed composites are observed at temperatures up to 600 °C due to the olive stone component. In the same temperature range, the changes in pyrolyzed novolac are smaller. The spectroscopic analysis shows that novolac pyrolyzed up to 900 ^°C has less defects and disorder than the composites. However, above 900 ^°C, pyrolyzed novolac becomes more disordered compared to the pyrolyzed composites. It is concluded that partial replacement of novolac by olive stone in the composite materials leads to the formation of a low cost, good quality product.     

Correlation between hydrogen‐bonding interaction and mechanical properties of polyimide fibers

Novel co‐polymerization polyimide (PI) fibers based on 4,4′‐oxydianiline (ODA)‐pyromellitic dianhydride (PMDA) were prepared. 2‐(4‐Aminophenyl)‐5‐aminobenzimidazole (PABZ) containing the N? H group was introduced into the structure of the fibers as the proton donor. The results of Fourier transform infrared (FTIR) and dynamic mechanical analysis (DMA) showed that hydrogen bonding occured between the N? H group and chains, which strongly enhanced interchain interaction. This hydrogen bonding interaction increased the tensile strength and initial modulus of the PI fibers up to 2.5 times and 26 times, respectively, compared to those of homo‐PI PMDA‐ODA fibers with no hydrogen‐bonding interaction because of the absence of proton donors after the imidization process. In the mean time, glass transition temperature (T_g) of the modified PI fibers was found to be 410–440°C, which was higher than that of the homo‐PI PMDA‐ODA fibers. From the result, a novel access to molecular design and manufacture of high performance PI fibers with good properties could be provided. Copyright © 2009 John Wiley & Sons, Ltd.     

Strength and toughness of carbon fibers reinforced rigid polyurethane composites by adsorbing tannic acid and refining Ni grains on carbon fibers surface

In this article, short carbon fibers (CFs) reinforced rigid polyurethane (RPU) composites were prepared with the aim of improving both strength and toughness. A tannic acid (TA)‐nickel (Ni) composite coating was spontaneously co‐deposited onto CFs surface by a one‐step electrodeposition method to strengthen the interface bonding of the composites. The satisfactory mechanical properties of the composites were mainly attributed to the superior interfacial adhesion. On the one hand, TA could play a role in refining Ni grain during electrodeposition. On the other hand, the hydroxyl groups attached to composite coating, which were introduced by TA, could react with the RPU matrix to form chemical bonds. When the composites were under stress, the chemical bonds could effectively transfer the stress from matrix to the interface, while the refined Ni crystals could greatly increase the stress transfer path, and thus improve the strength and toughness of the material. Compared with pure RPU, the tensile strength, bending strength,interlaminar shear strength, and impact strength of TA‐Ni‐coated CFs/RPU composites were improved by 14.8%, 83.1%, 28.7%, and 121.4%, respectively.