Optimization of extraction techniques for processing and utilization of Cyperus Dichrostachus A. Rich Plant as fiber

The Textile industry is an important contributor to the GDP of countries worldwide. Both natural and synthetic fibers are the main raw materials for this sector. Environmental concerns, depletion of non-renewable resources, the high price of oil and limited oil reserves with consumer demand is driving research into cheap, biodegradable, sustainable, renewable and abundantly available green materials. Natural fibers are of the good substitute sources for swapping synthetic fibers and reinforcing polymer matrices because of their contributions in maintaining of ecology, nature of disposal, low energy requirement for processing and sustainability. The current research emphases on evaluating and determining the best extraction methods to process and treat cyperus Dichrostachus A.Rich plant in order to make the fiber suitable for variety of applications. Cyperus Dichrostachus A.Rich plant was treated with two conditions (cold and warm conditions) using statistically planned tests. Process conditions were optimised using central composite design methodology with the experimental design. Under optimised conditions, the strength and fiber yield of CDA fibers were significantly compared. The strength and fiber yield of the fiber was at maximized with optimized conditions and use for valorisation applications.

A modified resistance to compression (RtC) test for evaluation of natural fiber softness

Comfort is a key feature of any clothing that relates significantly to softness of the fiber, yarn and fabric from which is it constructed. A known softness assessment method for fibers is the resistance to compression test. This traditional test only provides a single force value for the resistance of a loose fiber sample using a fixed mass under compression. In this research, a modified resistance to compression test was introduced to show the effects of repeated compression, providing more information about the softness and resilience of selected fibers. Three different natural fiber types, including wool, cotton and alpaca were compared using this new approach. The results showed compression profiles were quite different for different fiber types as well as for the same fibers with different diameters. While the diameters of the wool and alpaca samples were similar (18.5 μm), the modified resistance to compression values were significantly higher for wool (with a peak value at 9.5 kPa compared to 2.1 kPa for alpaca). Cotton was different from wool and alpaca but showed a similar modified resistance to compression value (10.4 kPa) to wool. During cycles of compression, modified resistance to compression peak values decreased slightly and then tended to be constant. Even though the structures of wool, cotton and alpaca were quite different, there was no significant difference in the magnitude of decline in modified resistance to compression peak values. This means that the modified resistance to compression test is able to provide additional information on the resilience characteristics of different natural fibers, and can reveal the resistance behavior of fiber samples during cyclic compression.

Natural Fillers as Potential Modifying Agents for Epoxy Composition: A Review

Epoxy resins as important organic matrices, thanks to their chemical structure and the possibility of modification, have unique properties, which contribute to the fact that these materials have been used in many composite industries for many years. Epoxy resins are repeatedly used in exacting applications due to their exquisite mechanical properties, thermal stability, scratch resistance, and chemical resistance. Moreover, epoxy materials also have really strong resistance to solvents, chemical attacks, and climatic aging. The presented features confirm the fact that there is a constant interest of scientists in the modification of resins and understanding its mechanisms, as well as in the development of these materials to obtain systems with the required properties. Most of the recent studies in the literature are focused on green fillers such as post-agricultural waste powder (cashew nuts powder, coconut shell powder, rice husks, date seed), grass fiber (bamboo fibers), bast/leaf fiber (hemp fibers, banana bark fibers, pineapple leaf), and other natural fibers (waste tea fibers, palm ash) as reinforcement for epoxy resins rather than traditional non-biodegradable fillers due to their sustainability, low cost, wide availability, and the use of waste, which is environmentally friendly. Furthermore, the advantages of natural fillers over traditional fillers are acceptable specific strength and modulus, lightweight, and good biodegradability, which is very desirable nowadays. Therefore, the development and progress of “green products” based on epoxy resin and natural fillers as reinforcements have been increasing. Many uses of natural plant-derived fillers include many plant wastes, such as banana bark, coconut shell, and waste peanut shell, can be found in the literature. Partially biodegradable polymers obtained by using natural fillers and epoxy polymers can successfully reduce the undesirable epoxy and synthetic fiber waste. Additionally, partially biopolymers based on epoxy resins, which will be presented in the paper, are more useful than commercial polymers due to the low cost and improved good thermomechanical properties.

A Review on Synthesis and Characterization of Activated Carbon from Natural Fibers for Supercapacitor Application

Supercapacitors have gained much attention in recent years due to their promising characteristics, such as high specific capacitance, high power density, long cycle life, and environment-friendly nature. Usage of natural sources for activated carbon synthesis is a major focus by many researchers worldwide for discovering a replacement of existing supercapacitors. This review summarizes the methods used to synthesize activated carbon (AC) from various natural fiber, their physical and electrochemical characteristics, and the improvement of supercapacitor electrode performance. Previous research studies indicate the practicability of activated carbon derived from various natural fibers with superior electrochemical properties. The effect of activating reagents and temperature on the electrochemical performance for supercapacitor applications are also highlighted in this paper. Since the nature of activated carbon from fibers and its synthesizing methods would result in different properties, the Cyclic Voltammetry (CV) study is also thoroughly discussed on the specific capacitance together with charge/discharge test to observe the capacitance retention after several cycles. Finally, a detailed approach of converting biowaste materials to activated carbon for energy storage applications with environmental concerns is explored.

Mechanics of Materials Natural Fibers Technology on Thermal Properties of Polymer

The thermal characteristics of polymathic methacrylate combined with unsaturated polyester were determined by numerical and experimental research. Models for numerically investigating the parameters of thermal conductivity, specific heat capacity, and thermal diffusivity were developed using COMSOL Multiphysics. The numerical data were then compared to experimental results for the same material using the same measurements to ensure that they were correct. By comparing the thermal conductivity data to two sets of theoretical data, the results were confirmed. The COMSOL models were quite close to the experimental data, with just minor differences between the three models. One set of theoretical data coincided with the mean of the other data, while the second set revealed a significant departure below the other data.

Influence of Palm Oil Fibers Length Variation on Mechanical Properties of Reinforced Crude Bricks

Crude bricks are composite materials manufactured with sediments and natural fibers. Natural fibers are waste materials and used in construction materials for reinforcement. Their reuse in manufacturing reinforced crude bricks is eco-friendly and improves mechanical and thermal characteristics of crude bricks. Factors such as type of fibers, percentage of fibers, length of fibers and distribution of fibers inside the bricks have significant effect on mechanical, physical and thermal properties of biobased composite materials. It can be observed by tests such as indirect tensile strength, compressive strength for mechanical characteristics, density, shrinkage, color for physical properties, thermal conductivity and resistivity for thermal properties, and inundation test for durability of crude bricks. In this study, mechanical and physical characteristics of crude bricks reinforced with palm oil fibers are investigated and effect of change in percentage and length of fibers is observed. Crude bricks of size 4*4*16 cm3 are manufactured with dredged sediments from Usumacinta River, Mexico and reinforced with palm oil fibers at laboratory scale. For this purpose, sediments and palm oil fibers characteristics were studied. Length of fibers used is 2cm and 3cm. Bricks manufacturing steps such as sediments fibers mixing, moulding, compaction and drying are elaborated. Dynamic compaction is opted for compaction of crude bricks due to energy control. Indirect tensile strength and compressive strength tests are conducted to identify the mechanical characteristics of crude bricks. Physical properties of bricks are studied through density and shrinkage. Durability of crude bricks is observed with inundation test. Thermal properties are studied with thermal conductivity and resistivity test. Distribution and orientation of fibers and fibers counting are done to observe the homogeneity of fibers inside the crude bricks. Finally, comparison between the mechanical characteristics of crude bricks manufactured with 2cm and 3cm length with control specimen was made.

Substitution of Synthetic Fibers by Bio-Based Fibers in a Structural Mortar

The use of bio-based material is now widespread in insulation concrete, for example hemp concrete. The bio-based materials in concrete provide many advantages: lightness, sound and thermal insulation, hydrothermal regulation while contributing to a reduction in the environmental impact due to the carbon capture during the plant growth. The development of materials incorporating plant is therefore an important objective for the construction. The next step will be to introduce bio-based materials in structural mortars and concretes. The project FIBRABETON proposes to substitute synthetic or metallic fibers by natural fibers in screed and slab. After a selection of biomass on the resources availability, separation and fractionation are the key step in processing to obtain technical natural fibers. Bulk fiber shaping and packaging methods for easy handling and transportation are tested. Then, functionalization of technical natural fibers by physical & chemical treatments to improve the durability with cement paste is carried out. The second step concerns the introduction of treated or not treated fibers in mortar and concrete formulations. The variation of the nature of the biomass, fibers shape and dosage in concrete are studied. The workability, the compressive strength and withdrawal resistance are measured in order to obtain the best formulation parameters. The evolution of properties over time is also evaluated. The project FIBRABETON is carried out with ESTP, FRD and Vicat and is subsidized by ADEME, Grand Est region and FEDER.

Valorization of Vegetal Fibers in Anti-Fissuration Screed Mortar Formulation

This work, which is part of the FIBRABETON project, aims to anti-fissuration screed formulations proposition based on natural fibers and comparing these formulations to a synthetic fiber-screed formulation. Different natural fiber (hemp, flax, miscanthus and bamboo) with contents rangingfrom 0.4% to 0.8% were tested. The spread (slump), the shrinkage and mechanical strength (flexural and compressive) studies were carried out. SEM images of natural fibers and natural fibers screed formulation were analyzed. Overall, it is found that all natural fibers screed formulations tested, have shown better behaviour than the synthetic fibers screed formulation in point of view workability, shrinkage and mechanical properties. The lowest shrinkage value is found in the case of the H5 (5 mm long hemp fibers) screed formulation. Generally speaking, the mechanical strength values (flexural and compressive) are more or less similar between natural soft fibers (hemp and flax) and rigid fibers (miscanthus and bamboo). Taking in account slump, shrinkage and mechanical behavior, the proposed good compromise in this work is the H5 screed formulation.

Mechanical Properties and Durability of Bamboo Fibers/Bamboo-Fiber-Mixed Spray Mortar for Slope Protection

Conventionally, short fibers such as steel and synthetic fibers have been mixed into spray mortar used for slope protection to enhance resistance against cracking and durability. However, in the quest of higher performance fiber-reinforced mortar with reduced impact on the environment, natural fibers such as bamboo fibers may play a vital role. Thus, the tensile strength and the bond strength of bamboo fibers used for spray mortar were examined by laboratory tests. The mechanical properties of bamboo-fiber-reinforced spray mortar were examined under cyclic wet and dry conditions along with its resistance against freezing and thawing by a spray test. It was confirmed that 0.75% mixture of bamboo fibers in spray mortar successfully improved mechanical properties and durability. These include adhesion strength to the base surface following exposure to cyclic wet/dry conditions and overall resistance against freezing/thawing. Moreover, higher compressive strength, flexural toughness and adhesion strength to the base surface were achieved by further mixing in vinylon fibers or fly ash in addition to bamboo fibers.