Mechanical Properties of Sisal/Cattail Hybrid-Reinforced Polyester Composites

Abstract

Due to environmental and energy conservation concerns, a thrust towards low-cost lightweight materials has resulted in renewed interest in the development of sustainable materials that can replace nonbiodegradable and environmentally unfriendly materials in reinforced composites. In this study, mechanical properties of a hybrid composite consisting of polyester resin reinforced with a blend of sisal and cattail fibres were evaluated. The composite was fabricated using a hand lay-up technique at varying hybrid fibre weight fractions (5 to 25 wt%) while maintaining a constant fibre blend ratio of 50/50. Composites were also prepared at a constant fibre weight fraction of 20% while varying the fibre blend ratio between 0 and 100%. Fabricated composites were then characterised in terms of flexural, tensile, compressive, and impact strengths following ASTM and ISO standards. Results showed that, at a constant fibre blend ratio of 50/50, there was increase in the mechanical properties as the fibre weight fraction increased from 5 to 20%. At a constant fibre weight fraction (20%), a positive improvement in flexural, tensile, and compressive properties was registered as the fibre blend ratio varied between 0 and 75% with optimal values at a sisal/cattail ratio of 75/25. The current study suggests that blending sisal and cattail fibres for production of polyester composites yields hybrid composites with enhanced mechanical properties.

Effects of alkali treatment on the mechanical and thermal properties of sisal/cattail polyester commingled composites

“…And thus, the high values of impact strengths reported for treated hybrid composites in this study may also be attributed to their failure modes (larger saw-like fractured surfaces and higher fiber breakages) as more impact energy is absorbed. Therefore, the major composite failure modes identified were fiber pull-outs (in untreated fibers) and fiber fracture (in treated fibers) corroborating a previous observation (Mbeche, Wambua & Githinji, 2020). Similarly, Rizal et al (2018) reported that failure in Typha fiber reinforced epoxy composites was due to fiber and matrix debonding, fiber pull-outs, and fiber damage.…”

“…The inner surfaces were then covered with aluminium foil to avoid the chances of composites sticking onto the mould surface and to provide good surface finish. The experimental design for the amount of matrix material and the reinforcements used in the composites follows from a preceding study (Mbeche, Wambua & Githinji, 2020) which indicated that the optimal weight fraction was 20% with 75/25 sisal/cattail fiber blend for optimal mechanical properties of the resultant polyester composites.…”

Peer Review #2 of "Effects of alkali treatment on the mechanical and thermal properties of sisal/cattail polyester commingled composites (v0.1)"

“…And thus, the high values of impact strengths reported for treated hybrid composites in this study may also be attributed to their failure modes (larger saw-like fractured surfaces and higher fiber breakages) as more impact energy is absorbed. Therefore, the major composite failure modes identified were fiber pull-outs (in untreated fibers) and fiber fracture (in treated fibers) corroborating a previous observation (Mbeche et al, 2020). Similarly, Rizal et al (2018) reported that failure in Typha fiber reinforced epoxy composites was due to fiber and matrix debonding, fiber pull-outs, and fiber damage.…”

“…The inner surfaces were then covered with aluminium foil to avoid the chances of composites sticking onto the mould surface and to provide good surface finish. The experimental design for the amount of matrix material and the reinforcements used in the composites follows from a preceding study (Mbeche, Wambua, & Githinji, 2020) which indicated that the optimal weight fraction was 20% with 75/25 sisal/cattail fiber blend for optimal mechanical properties of the resultant polyester composites. Unsaturated polyester resin (UPR) and hardener (MEKP) were mixed in a ratio of 0.02:1 by mass as per the manufacturer's instructions and stirred thoroughly.…”

Novel cattail fiber composites: converting waste biomass into reinforcement for composites

“…Previously, cattail plants have been investigated for composite applications using whole cattail leaves (Stanescu and Bolcu 2019 ; Bazwa et al 2015 ), decorticated cattail leaves (Wuzella et al 2011 ; Mbeche et al 2020 ), milled cattail leaf mesh (Kongkaew et al 2018 ), and individual fiber without conversion into non-woven mats (Sana et al 2015 ). The extraction of textile-grade fiber from the cattail leaves has been demonstrated by Rahman et al ( 2021 ).…”