Water absorption behavior of cellulosic fibres polymer composites: A review on its effects and remedies

Abstract

Recently, researchers and scientists are trying to overcome the environmental burden by using biocomposites in engineering applications as far as possible. The main source of biocomposites is cellulosic fibres which is a class of natural fibres. Instead of many advantages of cellulosic fibres, they and their polymer composites suffer from some limitations as well. The environmental conditions are one of the most important issues to degradation behavior of the cellulosic fibres polymer composites (CFPCs). Among the environmental conditions, water absorption is an important ground to degradation in the mechanical performance of the CFPCs, which resists them to be used in outdoor applications. Several studies have been presented on water absorption characteristics of cellulosic fibres and its polymer-based biocomposites. Further, the consequence of water uptake on the mechanical performance of biocomposites was also reported in many studies. In most of the cases, a negative effect of water absorption was observed, whereas in a few cases a positive effect was also seen. In the present study, mechanics and kinetics of water absorption for CFPCs are discussed. Further, a detailed literature review on water absorption of cellulosic fibres and their different types of polymer-based biocomposites has also been carried out. Furthermore, studies reported on the effect of water absorption on the mechanical properties were also systematically presented. Moreover, all the possible remedies to lower the water absorption capacity were also discussed in the present review paper.

Design and Development of False Ceiling Board Using Polyvinyl Acetate (PVAc) Composite Reinforced with False Banana Fibres and Filled with Sawdust

“…The results of water absorption test of composite sample manufactured with optimum percentage of the constituents (sawdust 40%, resin 40%, and fibre 20%) are shown in Figure 7 after 2-hour and 24-hour immersion in water. As seen, as immersion time increased, the amount of water absorbed in the composite also increased which follows Fick's diffusion law [39]. This could be because the raw materials used for the composite manufacture were inherently hydrophilic due to the presence of hydroxyl groups on their surfaces.…”

“…It also result in poor stress transfer and ultimately to specimen fracture in the long run [36,37]. The composite begins to swell when exposed to moisture giving rise to local strain in polymer matrix that causes microcracks, subsequently, decreasing the mechanical properties of composites [38,39]. The results of water absorption test of composite sample manufactured with optimum percentage of the constituents (sawdust 40%, resin 40%, and fibre 20%) are shown in Figure 7 after 2-hour and 24-hour immersion in water.…”

“…Figure 7 also shows the tensile strength of the composite reduced as the water absorbed increased. This is probably because the absorption completely terminates the bonding force between the fibre and matrix to a greater extent [39].…”

Variations in the mechanical properties of bionanocomposites by water absorption

“…8 Nowadays, many methods and treatments have been used to improve the water resistance performance of natural fibers by eliminating their hydrophilic constituents. 9…”

“…Nanocellulose fibers can form strong transparent films and porous dense aerogels, which offer attention to new areas such as biomedical and electronics. 10 Recently, bionanocomposites have been used in several applications such as biomedical (bone tissue regeneration, artificial blood vessels, and dura mater reconstruction), 11–14 electronic devices (display device, e-papers, flexible light-emitting diode, and head phone diaphragm), 15–17 packaging, 9,10 paper strength enhancement, 11 and coating and structure. 12–14…”