Valorization of Agricultural Residues for Cellulose Nanofibrils Production and Their Use in Nanocomposite Manufacturing

This paper reports the isolation of cellulose nanofibrils (CNFs) from almond stems, available as agricultural residues. The CNF suspensions were prepared by the combination of chemical and mechanical treatment: the microscopic fibres were firstly isolated by the delignification-bleaching process, followed by TEMPO-mediated oxidation to facilitate the further nanofibrillation using high-pressure homogenization process at 600 bar for 10 passes as a mechanical treatment. The ensuing CNFs were characterized by several methods, such as transmission electron microscopy (TEM), degree of fibrillation, and carboxyl content. Different nanocomposites were prepared by casting-evaporation method from the mixture of CNF suspension in the commercial acrylic latex as a matrix. The effect of CNF loading on mechanical and thermal properties of the composites was then studied. The considerable enhancement of both Young’s modulus and tensile strength was observed, which clearly indicates that the nanocomposites reinforced with the nanofibrils from Prunus amygdalus have promising mechanical properties

Cellulosic Fibers from Lignocellulosic Biomass for Papermaking Applications

This chapter gives a brief overview of the cellulose extraction from Opuntia (Cactaceae) fibers. The suitability of this food waste for pulp and paper production was investigated by the determination of the chemical composition and testing two procedures of delignification: chemical and semichemical pulping processes. Chemical pulping procedure was carried out by using soda-anthraquinone (soda-AQ) mixture, and semichemical pulping process was performed by softening the raw material using soda-hydrogen peroxide (soda-HP) mixture; this operation was followed by mechanical grinding. The obtained fibrous suspensions were characterized by measuring their dimension parameters (fiber length, fiber width, and fine elements), polymerization degree, and their retention water capacity. The effect of pulping process on yield and fiber characteristics in each pulp was studied. The surface morphologies of the produced papers were studied using scanning electron microscope (SEM), and results show the good distribution and individuality of fibers. The structural and mechanical properties of the prepared paper were presented and discussed. Mechanical strength results show the good tenacity of papers made from soda-HP pulping process

Novel Trend in the Use of <em>Opuntia</em> (Cactaceae) Fibers as Potential Feedstock for Material Science Applications

Lignocellulosic fibers from Opuntia biomass, family Cactaceae, were mainly studied for their sustainability and cellulose content richness. This chapter highlights the current exploitation of Opuntia (Cactaceae) as potential feedstock for value-added applications such as reinforcement in composites and paper manufacturing. Cellulosic fibrous network fractions were isolated from different plant parts, and their fundamental properties, chemical and structural compositions, were analyzed, and the obtained results were discussed. The obtained fibrous networks were incorporated into two thermoplastic polymers; their enhancement properties and biodegradability have been studied. However, different recent methods of cellulose fiber extractions (pulping) and paper manufacturing have been investigated by testing two procedures of delignification: chemical and semi-chemical pulping process; these operations were followed by fibrous suspension characterizations and paper productions. The obtained results show the suitability of Opuntia (Cactaceae) for the new trend in ecological and green materials

Angiomyolipome épithélioïde rénal mimant un carcinome rénal

L’angiomyolipome épithélioide est une forme rare d’angiomyolipome à potentiel malin, considéré récemment par l’OMS comme une entité à part dans la classification des tumeurs rénales. Cette lésion pose un problème dans le diagnostic différentiel avec les carcinomes à cellules claires. Il n’y a pas de critère spécifique clinique ou radiologique caractérisant cette tumeur. L’immunohistochimie en révélant la positivité des cellules épithélioide au marqueur HMB45 est essentielle au diagnostic. Le traitement doit être discuté en concertation pluridisciplinaire.Pan African Medical Journal 2016; 2

Integral Valorization of Posidonia oceanica Balls: An Abundant and Potential Biomass

Posidonia oceanica balls (POB), a kind of seagrass, are a significant environmental issue since they are annually discharged onto beaches. Their current usefulness limits interest in their management and enhances the environmental problem. Therefore, in this research, the potential of this lignocellulosic biomass was studied from a holistic biorefinery point of view. To this end, an in-depth study was carried out to select the best pathway for the integral valorization of POBs. First, an autohydrolysis process was studied for the recovery of oligosaccharides. Then, a delignification stage was applied, where, in addition to studying different delignification methods, the influence of the autohydrolysis pre-treatment was also investigated. Finally, cellulose nanofibers (CNFs) were obtained through a chemo-mechanical treatment. The results showed that autohydrolysis not only improved the delignification process and its products, but also allowed the hemicelluloses to be valorized. Acetoformosolv delignification proved to be the most successful in terms of lignin and cellulose properties. However, alkaline delignification was able to extract the highest amount of lignin with low purity. CNFs were also successfully produced from bleached solids. Therefore, the potential of POB as a feedstock for a biorefinery was confirmed, and the pathway should be chosen according to the requirements of the desired end products.This research was funded by the Ministry of Higher Education and Scientific Research of Tunisia and Gobierno Vasco/Eusko Jaurlaritza grant number IT-1498-22

Maximum Quasi-Static Indentation Stress Analysis of Flax/Epoxy and Glass/Epoxy Polymer Composites

The use of fibers is growing every day to meet the demands of the industry. Both synthetic and natural fibers offer benefits and drawbacks that are best suited to specific applications. Synthetic fibers are preferable to natural fibers because they have greater mechanical properties. However, in their application, synthetic fibers have a negative influence on the environment as they are not biodegradable. As a result, natural fibers as an alternative will reduce the environmental impact, though their properties are not as good as synthetic fibers. ANSYS APDL, one of the FEA software analysis, is used to perform quasi-static indentation (QSI) tests in this research work. The purpose of this study is to determine the influence of fiber orientations of 0°, 15°, 30°, 45°, 60°, 75°, and 90°, as well as the effect of the supporting ply angle, 0°, on the mechanical properties of Flax FRP composite. For layup sequences of [(+θ,-θ)2]S and [(±θ)2,04]S, it was observed that maximum strength increases from 0° to 90° fiber orientation. Meanwhile, in a QSI test, the highest strength of Flax FRP was found at 45° for both [(+θ,-θ)2]S and [(±θ)2,04]S layup sequences, with 94.20 MPa and 96.80 MPa respectively. The effect of fiber volume fraction, such as Glass FRP composites with fiber volume fractions of 30% and 60% shows that the fiber volume fraction for 60% has a better performance than 30%. Therefore, composites with a higher fiber volume fraction show better maximum strength and lower deformability. The results of modeling and simulation work on Flax FRP composites can aid in the development of new materials that are more sustainable than conventional techniques by anticipating the mechanical behavior of natural FRP composites

Maximum Quasi-Static Indentation Stress Analysis of Flax/Epoxy and Glass/Epoxy Polymer Composites

The use of fibers is growing every day to meet the demands of the industry. Both synthetic and natural fibers offer benefits and drawbacks that are best suited to specific applications. Synthetic fibers are preferable to natural fibers because they have greater mechanical properties. However, in their application, synthetic fibers have a negative influence on the environment as they are not biodegradable. As a result, natural fibers as an alternative will reduce the environmental impact, though their properties are not as good as synthetic fibers. ANSYS APDL, one of the FEA software analysis, is used to perform quasi-static indentation (QSI) tests in this research work. The purpose of this study is to determine the influence of fiber orientations of 0°, 15°, 30°, 45°, 60°, 75°, and 90°, as well as the effect of the supporting ply angle, 0°, on the mechanical properties of Flax FRP composite. For layup sequences of [(+θ,-θ)2]S and [(±θ)2,04]S, it was observed that maximum strength increases from 0° to 90° fiber orientation. Meanwhile, in a QSI test, the highest strength of Flax FRP was found at 45° for both [(+θ,-θ)2]S and [(±θ)2,04]S layup sequences, with 94.20 MPa and 96.80 MPa respectively. The effect of fiber volume fraction, such as Glass FRP composites with fiber volume fractions of 30% and 60% shows that the fiber volume fraction for 60% has a better performance than 30%. Therefore, composites with a higher fiber volume fraction show better maximum strength and lower deformability. The results of modeling and simulation work on Flax FRP composites can aid in the development of new materials that are more sustainable than conventional techniques by anticipating the mechanical behavior of natural FRP composites

Green composites based on wheat gluten matrix and posidonia oceanica waste fibers as reinforcements

[EN] In this work, green composites from renewable resources were manufactured and characterized. A fibrous material derived from Posidonia oceanica wastes with high cellulose content (close to 90 wt% of the total organic component) was used as reinforcing material. The polymeric matrix to bind the fibers was a protein (wheat gluten) type material. Composites were made by hot-press molding by varying the gluten content on composites in the 10¿40 wt% range. Mechanical properties were evaluated by standardized flexural tests. Thermo-mechanical behavior of composites was evaluated with dynamic mechanical analysis (torsion DMA) and determination of heat deflection temperature. Morphology of samples was studied by scanning electronic microscopy and the water uptake in terms of the water submerged time was evaluated to determine the maximum water uptake of the fibers in the composites. Composites with 10¿40 wt% gluten show interesting mechanical performance, similar or even higher to many commodity and technical plastics, such as polypropylene. Water resistance of these composites increases with the amount of gluten. Therefore, the sensitiveness to the water of the composites can be tailored with the amount of gluten in their formulation.The authors would like to acknowledge the Wallenberg and Lars-Erik Thunholms Foundation for the economical support through the concession of a Postdoctoral Fellowship in Forest related. Authors would also like to thank Marcos and Elena for helping in collecting P. oceanica balls.Ferrero Penadés, B.; Boronat Vitoria, T.; Moriana Torró, R.; Fenollar Gimeno, OÁ.; Balart Gimeno, RA. (2013). Green composites based on wheat gluten matrix and posidonia oceanica waste fibers as reinforcements. Polymer Composites. 34(10):1663-1669. doi:10.1002/pc.22567S16631669341

The Effect of Eggshell Fillers on the Physical, Mechanical, and Morphological Properties of Date palm Fibre Reinforced Bio-epoxy Composites

Natural fibres have remained increasingly applied as reinforcement filler in polymer matrix for fabrication of composites for a long time. Environmentally friendly and sustainable fibres offer the possibility of a feasible substitute and alternative materials to synthetic fibres for a diverse range of products from composite materials. In this research, a new bio-composite has been produced by using date palm fibre (DP) and eggshell (ES) wastes into bio matrix. The current work focuses on how ES particles affect the physical, mechanical, and morphological aspects of DP/bio-epoxy composites. Bio-composites was manufactured by using a fibre loading of 40 wt% DP and filler concentrations of 5, 10, 15, and 20 wt% ES by closed mold hot press. A DP/bio-epoxy composite without ES filler was also prepared as control. Characterization of bio-composites was carried out as per ASTM standard. The obtained results indicate that ES can be used as a filler in bio-epoxy with this novel material composition. Mechanical properties results show that 15 wt% by weight of the ES particles filler loading displays good tensile and flexural properties with better impact strength at 5 wt%. The incorporation of ES above 15 wt% in DP/bio-epoxy composite is not remarkable, so 15 wt% filler matrix replacement is recommended. Furthermore, scanning electron microscopy (SEM) reveals fracture in matrix, implying that the bio-epoxy polymer structures are altered by the fillers. We concluded from findings that ES particles can utilize as potential source of green raw material for strengthening in polymer composites and ultimately help to establish its potential in structural applications

Ecofriendly Dyeing of Textile Materials with Natural Colorants from Date Palm Fiber Fibrillium

Natural dyes have become an interesting subject of study because of their superior ecological properties in comparison to their synthetic counterparts. This explains the great amount of research developed in this regard, especially when the dye used was derived from a natural product’s waste. This research aims to evaluate the affinity of the dye extracted from date palm fibrillium to a multifiber fabric. This choice was made to investigate a comparison of the dyeability of many kinds of textile fibers with the obtained colorant from the date palm fibrillium. It was shown that the different types of fibers were well-dyed. The darkest dyes were obtained especially by using wool and nylon fabrics. In view of these results, wool and nylon fibers were selected for developing a dyeing investigation. The effect of the most important operational conditions such as temperature, pH, and dyeing time on the dyeing quality results has been investigated. Color yield (K/S) and CIELab values (L*, a*, b*, C*, h*) were used to evaluate the dyeing properties. The utilization of durable chemicals and bio-mordants both pre and post-dyeing resulted not only in new dyes but also in improved speed rates