Ply-stacking effects on mechanical properties of Kevlar-29/banana woven mats reinforced epoxy hybrid composites

© The Author(s) 2022. This is an open access article distributed under the Creative Commons Attribution License, to view a copy of the license, https://creativecommons.org/licenses/by-nc/4.0/Development of new hybrid laminated composites of Kevlar-29 (K-29)/banana fiber (Musa acuminata) mats to meet future demand for fiber reinforced polymer (FRP) composites has been investigated. The different ply-stacking sequenced Kevlar (K)/natural (N) banana reinforced epoxy polymeric hybrid composite samples were designated as KN1, KN2, KN3, KN4, KN5 and KN6, in addition to NN7 and KK8 for single or non-hybrid FRP (control) composite samples. The ply-stacking effects on mechanical properties of all the laminated composite were investigated. The maximum tensile, flexural, impact and interlaminar shear strengths (ILSS) were obtained with sample KN4, because of the stacking of its Kevlar and natural banana mats, which was K2/N4/K2 of 8 layers and different from other stacking sequences. The percentage improvements on tensile strength of sample KN4 when compared with other hybrid composite samples KN1, KN2, KN3, KN5 and KN6 were 6.3, 4.4, 3.6, 13.1 and 11.3%, respectively. While, same optimum sample KN4 recorded highest flexural strength among hybrid samples with percentage improvements of 122.19, 70.97, 31.03 and 83.68% when compared with other hybrid samples KN2, KN3, KN5 and KN6, respectively. Similar trend of results was obtained for their tensile and flexural moduli. But, both hybrid composite samples KN3 and KN4 recorded higher impact strengths of 3.0 and 2.8 J, respectively, when compared with other hybrid counterparts. The tensile and flexural strengths of sample KN4 were 147.48 and 223.69 MPa, respectively. The tensile properties of various theoretical model were compared with experimental values.Peer reviewe

Investigation of chemically treated longitudinally oriented snake grass fiber-reinforced isophthallic polyester composites

Snake grass fibers are subjected to various chemical surface modifications such as alkali, benzoyl peroxide, benzoyl chloride, potassium permanganate and stearic acid. These fibers are utilized to fabricate the longitudinal oriented fiber-reinforced composites at 40% weight fraction of fiber. The mechanical properties of treated fiber composites are found to be higher than those of raw ones. Potassium permanganate treated fiber composites has optimum mechanical properties than other chemicals treated snake grass fibers composites. The scanning electron microscopic images of the tensile and impact fractured composites containing treated and untreated fibers have been examined. The fiber pull-out from the specimen has been found low for the treated fibers compared to untreated fiber composites. The kinetics of water absorption of the composites studied at various time intervals and temperature reveals that the treated fiber-reinforced composites has less water uptake compared to untreated one. </jats:p

Investigation of chemically treated randomly oriented sansevieria ehrenbergii fiber reinforced isophthallic polyester composites

Surface treatment of sansevieria ehrenbergii fibers were carried out using various chemicals like alkali, benzoyl peroxide, benzoyl chloride, permanganate and stearic acid in order to improve the interfacial bonding between the fiber and matrix. Polyester composites were prepared using raw and surface-treated fibers. Morphology and physico-mechanical properties of the prepared composites are analyzed and compared with pure resin. Fourier transform infra-red spectroscopic analysis examined for the chemically treated fibers affirm the removal of moisture, hemicellulose, lignin and wax content. Scanning electron microscopic images prove the formation of rough surface on the fiber after chemical treatment due to the removal of lignocellulose content. The physico-mechanical properties of the treated fiber reinforced polyester composites are enhanced due to good physical interaction between the fiber and polymer matrix. The chemically treated fiber shows lower water absorption compared to untreated fiber composites. </jats:p

Mechanical properties of randomly oriented snake grass fiber with banana and coir fiber-reinforced hybrid composites

Composite materials are extensively used in the structural applications due to its enhanced load-bearing capabilities. Mostly, the mechanical properties of the natural fiber-reinforced hybrid composites are better than the single fiber-reinforced composites and almost equal to the synthetic fiber composites. This paper presents the extraction and preparation methodology of the isophtallic polyester composites using the naturally available fibers like snake grass, banana and coir fibers. The tensile and flexural properties of the snake grass fiber-reinforced composites are compared with the snake grass/banana and snake grass/coir fiber-reinforced hybrid composites. The stress–strain curves of the snake grass, snake grass/banana and snake grass/coir fiber composites and the fiber pull-outs in the fractured specimen are analyzed for the higher and lower mechanical properties. The result shows that the snake grass/banana and snake grass/coir fiber composites have the maximum tensile and flexural properties when compared with the snake grass fiber composites. </jats:p

Synergistic effect of fiber content and length on mechanical and water absorption behaviors of <i>Phoenix</i> sp. fiber-reinforced epoxy composites

Phoenix sp. fiber-reinforced epoxy composites have been manufactured using compression molding technique. The effect of reinforcement volume content (0%, 10%, 20%, 30%, 40%, and 50%) and size (300 µm particles, 10 mm, 20 mm, and 30 mm fibers) on quasi-static and dynamic mechanical properties was investigated. Moreover, the water absorption properties of composites were analyzed at different environmental conditions (10℃, 30℃, and 60℃). For each reinforcement size, composites loaded with 40% in volume show highest tensile and flexural properties. Furthermore, composites with 300 µm particles present the best impact properties and the lowest water absorption, regardless of the environmental condition. The dynamic mechanical properties of the composites loaded with 40% in volume were analyzed by varying the reinforcement size and the load frequency (i.e., 0.5 Hz, 1 Hz, 2 Hz, 5 Hz, and 10 Hz). It was found that the glass transition temperature of short fiber-reinforced composites is higher than that of the composite loaded with particles. </jats:p