The mechanical, physical and thermal characterization of a composite made from woven raffia fiber vinifiera molded in epoxy resin intended for shipbuilding shows that the density (0.5 g/cm3 with a relative error of 0....The mechanical, physical and thermal characterization of a composite made from woven raffia fiber vinifiera molded in epoxy resin intended for shipbuilding shows that the density (0.5 g/cm3 with a relative error of 0.05 g/cm3) of the composite produced is lower than that of wood used in this field. The material has low porosity (9.8%) and is less absorbent (12.61%) than wood. The result of the thermal conductivity test by the hot plane method shows that this composite can contribute to the internal thermal insulation (an example of thermal conductivity is 0.32W/m.K) of floating boats. The mechanical tests of compression (young modulus is 22.86 GPa), resilience (1.238 J/Cm2) and hardness (233.04 BH30-2.5/187.5-15s) show that this composite is much harder and more absorbent than many wood and bio-composite materials used in the construction of pleasure boats. The abrasion test (0.005349) shows that this composite could well resist friction with the beach.展开更多
This article contributes to the development of the new class of fully biodegradable “green” composites by combining fibers (natural/bio) with biodegradable resin. The vegetable fibers (Triumfetta cordifolia and suga...This article contributes to the development of the new class of fully biodegradable “green” composites by combining fibers (natural/bio) with biodegradable resin. The vegetable fibers (Triumfetta cordifolia and sugarcane bagasse) treated with NaOH and bleached were incorporated into a natural rubber matrix. The influence of the fiber ratio on the physical properties, tensile strength and surface hardness of the hybrid composites was analyzed. The results show that the addition of fibers in the natural rubber matrix increases the water absorption capacity but gradually reduces it with increasing fiber ratio. The hybrid composites of the NRT50-50B proportions show the best tensile strengths at 20 phr and a shore A hardness of 43.7 at 30 phr. The combination of two fibers has improved the physical and mechanical properties of the hybrid composites which can be used in engineering applications.展开更多
This work aims to characterize the physical,chemical,and thermal properties of hazelnut shells of the“Coula edulis”variety,originating from the south of Cameroon.The samples were divided into two zones(polar and equ...This work aims to characterize the physical,chemical,and thermal properties of hazelnut shells of the“Coula edulis”variety,originating from the south of Cameroon.The samples were divided into two zones(polar and equatorial)to study absorption and drying under four isotherms.The analyses allowed for the determination of the diffusion coefficient,the corrected diffusion coefficient,the relative humidity rate(RHR),and the activation energy using the gravimetric method.The results show that the relative humidity rate(RHR),of the polar region is higher than that of the equatorial region,while the diffusion coe-fficients and corrected diffusion gradually decrease.Among the models tested,the Page model best predicts humidity variations,while the Newton and Lewis models stand out for describing the drying phenomenon.“Coula edulis”has a dense structure with low porosity and limited water absorption,demonstrating their mechanical strength and dimensional stability.FTIR analysis highlights the presence of major lignocellulosic compounds(cellulose,hemicellulose,and lignin),while XRD reveals moderate crystallinity associated with mineral phases.ATG/DTG confirms good thermal stability up to high temperatures.These properties position the“Coula edulis”shells as a promising material for appli-cations in bio-composites,thermal and acoustic insulation,or even as sustaina-ble materials with a view to a circular economy.展开更多
文摘The mechanical, physical and thermal characterization of a composite made from woven raffia fiber vinifiera molded in epoxy resin intended for shipbuilding shows that the density (0.5 g/cm3 with a relative error of 0.05 g/cm3) of the composite produced is lower than that of wood used in this field. The material has low porosity (9.8%) and is less absorbent (12.61%) than wood. The result of the thermal conductivity test by the hot plane method shows that this composite can contribute to the internal thermal insulation (an example of thermal conductivity is 0.32W/m.K) of floating boats. The mechanical tests of compression (young modulus is 22.86 GPa), resilience (1.238 J/Cm2) and hardness (233.04 BH30-2.5/187.5-15s) show that this composite is much harder and more absorbent than many wood and bio-composite materials used in the construction of pleasure boats. The abrasion test (0.005349) shows that this composite could well resist friction with the beach.
文摘This article contributes to the development of the new class of fully biodegradable “green” composites by combining fibers (natural/bio) with biodegradable resin. The vegetable fibers (Triumfetta cordifolia and sugarcane bagasse) treated with NaOH and bleached were incorporated into a natural rubber matrix. The influence of the fiber ratio on the physical properties, tensile strength and surface hardness of the hybrid composites was analyzed. The results show that the addition of fibers in the natural rubber matrix increases the water absorption capacity but gradually reduces it with increasing fiber ratio. The hybrid composites of the NRT50-50B proportions show the best tensile strengths at 20 phr and a shore A hardness of 43.7 at 30 phr. The combination of two fibers has improved the physical and mechanical properties of the hybrid composites which can be used in engineering applications.
文摘This work aims to characterize the physical,chemical,and thermal properties of hazelnut shells of the“Coula edulis”variety,originating from the south of Cameroon.The samples were divided into two zones(polar and equatorial)to study absorption and drying under four isotherms.The analyses allowed for the determination of the diffusion coefficient,the corrected diffusion coefficient,the relative humidity rate(RHR),and the activation energy using the gravimetric method.The results show that the relative humidity rate(RHR),of the polar region is higher than that of the equatorial region,while the diffusion coe-fficients and corrected diffusion gradually decrease.Among the models tested,the Page model best predicts humidity variations,while the Newton and Lewis models stand out for describing the drying phenomenon.“Coula edulis”has a dense structure with low porosity and limited water absorption,demonstrating their mechanical strength and dimensional stability.FTIR analysis highlights the presence of major lignocellulosic compounds(cellulose,hemicellulose,and lignin),while XRD reveals moderate crystallinity associated with mineral phases.ATG/DTG confirms good thermal stability up to high temperatures.These properties position the“Coula edulis”shells as a promising material for appli-cations in bio-composites,thermal and acoustic insulation,or even as sustaina-ble materials with a view to a circular economy.
