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.

An Experimental and Analytical Study on the Bending Performance of CFRP-Reinforced Glulam Beams

The fiber-reinforced polymer is one kind of composite material made of synthetic fiber and resin, which has attracted research interests for the reinforcement of timber elements. In this study, 18 glued-laminated (glulam) beams, unreinforced or reinforced with internally embedded carbon fiber–reinforced polymer (CFRP) sheets, were tested under four-point bending loads. For the reinforced glulam beams, the influences of the strengthening ratio, the modulus of elasticity of the CFRP, and the CFRP arrangement on their bending performance were experimentally investigated. Subsequently, a finite element model developed was verified with the experimental results; furthermore, a general theoretical model considering the typical tensile failure mode was employed to predict the bending–resisting capacities of the reinforced glulam beams. It is found that the reinforced glulam beams are featured with relatively ductile bending failure, compared to the brittle tensile failure of the unreinforced ones. Besides, the compressive properties of the uppermost grain of the glulam can be fully utilized in the CFRP-reinforced beams. For the beams with a 0.040% strengthening ratio, the bending–resisting capacity and the maximum deflection can be enhanced approximately by 6.51 and 12.02%, respectively. The difference between the experimental results and the numerical results and that between the experimental results and analytical results are within 20 and 10%, respectively.

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.

A Study on the Conservation and Management of the Painting of Shamanistic Spirits in Chiseonggwang Buddha

This study presents a method for conserving shamanistic spirits in Chiseonggwang Buddha. Scientific investigation has revealed that these spirits have been subject to degeneration as a result of severe exfoliation and pollution. The materials and preservation treatment techniques used in create these shamanistic spirits were identified through visual inspection and using appropriate scientific equipment. The different types of background paper, background material, and color pigments used in create the shamanistic spirits were analyzed using a colorimeter, stereoscopic microscope, and SEM-EDS techniques. The analysis revealed that the pulp paper was used as the background and synthetic fiber polyester as the background material. In addition, the study of the pigment revealed that the color components were all synthetic, except for red lead [Pb3O4] and oyster shell white [CaCO3]. Moreover, it was confirmed that the green pigment, identified as emerald green [Cu(C2H3O2)2.3Cu(AsO2)2], was a major component of shamanistic spirits in the late 19th century. The shamanistic spirits in Chiseonggwang Buddha were conserved by identifying raw materials and pigments through this detailed analysis.

Influence of Volume Percentage and Fibers Alignments of Banana Fiber on Impact Strength of Epoxy Banana Composite

The world that is evolving at a very fast pace, the anxiety of the environment pollutions increasing has tip the necessity for new eco-friendly materials, researchers have started to develop sustainable materials that are renewable as well as biodegradable in nature. The natural fibers have certain advantages above synthetic fiber materials, they are lower in cost and density with comparable strength. In the present study, banana fiber is reinforced in the epoxy matrix and a composite material is prepared and impact strength of these composites are estimated. This composite samples are prepared by Wet lay-up method with varying banana fibers volume percentages by (10%, 20%, 30%, 40%) and by changing the fibers orientation in the epoxy matrix by (00 ,900 , woven Bi-directional). The results shows that there is gradual increase in the impact strength of the epoxy for 900 banana fiber orientation, the optimum results were found for 40% banana fiber and 60% epoxy resin, as for woven BD there was an increase in the impact strength up to 20% banana fiber reinforcement, as for 00 orientation the strength increases up to 10% fiber reinforcement above this there was a drastic reduction in the impact strength. Keywords: Banana Fiber, Epoxy Resin, Volume percent, Fiber Orientation, Impact Strength

Characterization of a New Fiber From Cyperus Dichrostachus A.Rich Plant

Natural fibers are of the good substitute sources for swapping synthetic fibers and reinforcing polymer matrices because of their contributions in maintaining of ecology, low energy requirement for processing and sustainability. The aim of this study is to characterize new fiber from Cyperus Dichrostachus A.Rich (CDA) plant. The CDA plant is a perennial non woody grass found in Ethiopian high lands and river basins. The fiber from this plant has good chemical composition of Cellulose (60.27%), hemicellulose (22.72%), lignin (16.59%) contents. It is light fiber having a density of 1010kg/m3 and good tenacity behaviour of 105.76cN/Tex with low elongation of 4.88%. The thermal stability of Cyperus Dicrostachys A,Rich fiber (CDAF) was studied using TGA and DTG analysis and revealed that the cellulose degraded at a temperature of 377.1°C. Fourier transform-infrared spectroscopy analysis confirmed that CDAF is rich in cellulose content. Furthermore, the properties of CDAF ensured that it can play a vital role as new reinforcement material and best alternative in bio composite industries. This will give competitive advantages when evaluated with other natural fibers reveals that there are significant potential benefits in implementation of “cleaner production” in textile material production industries. Specifically, replacement of synthetic fiber source with renewable biomass will reduce the environmental impact of these fibers. The future study will entail on investigating the possible valorization route especially in paper board, composite reinforcement and bio composite applications.

Two Stages Thermal and Catalytic Cracking of Polyethylene Terephthalate to Fuel Production

PET (polyethylene terephthalate) is made up of polymerized repeating units of the ethylene terephthalate monomer (C10H8O4). PET is a recyclable plastic with the number 1 as its identification code. PET, which has a molecular weight of 192 gm/mole and contains 62.5 percent carbon, 33.3 percent oxygen, and 4.2 percent hydrogen, is utilized as synthetic fiber, polyester, plastic packaging, and soft drink containers all over the world. The main purpose of this study is to convert PET waste into liquid hydrocarbon fuel. Because PET use has risen significantly over the world, and the bulk of garbage is thrown into the soil rather than recycled, posing an environmental risk. During the heat breakdown phase, PET decomposes. It creates very strong and solid non-biodegradable terephthalic acid and benzoic acid complexes. To obtain liquid hydrocarbon fuel from PET, at 250-300℃, calcium hydroxide Ca(OH)2 is used as a catalyst in this study.