Characterisation of the Anisotropic Thermoelastic Properties of Natural Fibres for Composite Reinforcement

Abstract

There has been a substantial increase in the investigation of the potential of natural fibres as a replacement reinforcement in the traditional fibre reinforced polymer composite application. However, many researchers often overlook the anisotropic properties of these fibres, and the estimation of the potential reinforcement performance. A full understanding of the thermoelastic anisotropy of natural fibres is important for realistically predicting their potential performance in composite applications. In this study, the thermoelastic properties of flax and sisal fibres were determined through a combination of experimental measurements and micromechanical modelling. The results confirm the high degree of anisotropy in properties of the flax and sisal fibres. The implications of these results on using natural fibres as an engineering composite reinforcement are discussed.

A Review of the Impact Performance of Natural Fiber Thermoplastic Composites

“…As stated in the Introduction many researchers of natural fiber composites enthusiastically discuss the potential of natural fibers to replace glass fibers in semi-structural and structural composite applications. We have often commented on the research and commercial challenges that such statements pose to those tasked with new materials development (Thomason, 2009a(Thomason, , 2010Thomason et al, 2011Thomason et al, , 2017Thomason and Carruthers, 2012). Not the least of such challenges is the level of reinforcement performance required from NF in order to succeed in engineering composite applications where a sufficient or high level of performance of a single mechanical performance parameter is very rarely sufficient to justify the use of a material in any particular application.…”

Fiber Orientation and Concentration in an Injection-Molded Ethylene-Propylene Copolymer Reinforced by Hemp

“…Several authors recorded Young's modulus for hemp fibers in the range of 30 to 70 GPa, without giving information about the dimensions or composition of the fibers studied [5][6][7]. Only a few studies mention the anisotropic behavior of natural fibers like hemp [43,44]. The authors attempted to estimate the transverse thermoelastic properties of natural fibers through a combination of experimental measurements and micromechanical modeling on unidirectionally aligned short fiber composites.…”

“…As for mechanical testing, the CTE experiments highlight the strong anisotropy in the elastic properties of hemp fibers. Some authors combine experimental measurements and micromechanical modeling on unidirectionally aligned short fiber composites to assess the CTE of natural fibers in longitudinal and transverse directions [43,44]. For all the studied fibers, a negative longitudinal CTE was shown for temperatures ranging from −50 to 50 • C, about −1.0 × 10 −5 K −1 at room temperature, whereas the transverse CTE was close to that of the polymeric matrix, namely 8.0 × 10 −5 K −1 .…”

Bacterial cellulose-natural fiber composites produced by fibers extracted from banana peel waste

“…Due to their cellular and hollow structure, natural fibers exhibit high specific stiffness and strength but dimensional inconsistency, lower linear thermal coefficient of expansion (LTCE), water sensitivity, mechanical degradation during processing, and low compatibility with many hydrophobic polymeric matrices are among their commonly known drawbacks [5,6]. Because excessive fiber shrinkage as compared to the polymer matrix contributes to poor fiber-matrix interface and ultimately reduces the overall mechanical performance of the composites [7]. Surface treatment and modification of natural fibers are essential to improve the interaction between reinforcing fibers and the polymer matrix.…”