Longitudinal mechanical properties of cell wall of Masson pine (Pinus massoniana Lamb) as related to moisture content: A nanoindentation study

Abstract

The in situ imaging nanoindentation technique was used to investigate how the moisture content (MC) affects the longitudinal mechanical properties of Masson pine cell wall. Furthermore, nanoindentation tests in liquid water were performed. The results indicate that elastic modulus, hardness, and compression yield stress of wood wall are all linearly correlated to the selected MC region in the range from 4.5% to 13.1%. Remarkable differences were found between the experimental values measured in water and the extrapolated values based on regression equations below fiber saturation point.

Effects of Moisture Content on the Mechanical Properties of Moso Bamboo at the Macroscopic and Cellular Levels

“…This indicated that the hardness of the bamboo fiber cell walls was much more sensitive to MC than was the elastic modulus. Similar results were also found for Masson Pine cell walls (Yu et al 2011). The difference in K value between H IT and E IT could be used to explain the response of the longitudinal compression properties of bamboo to the MC at the macro level, as hardness can provide valuable information about longitudinal compression yield stress (FischerCripps 2004).…”

“…The detailed procedure for nanoindentation testing in water can be found by referring to Yu et al (2011). All the samples were conditioned overnight before testing.…”

“…The results have revealed that almost all the mechanical properties, such as compressive strength, hardness, and modulus of elasticity, decrease with increasing MC below the fiber saturation point (FSP) (Cave 1978;Green et al 1986Green et al , 1988Kretschmann and Green 1996;Wang and Wang 1999;Kojima and Yamamoto 2004). Moreover, the sensitivities of different mechanical properties to changes in the MC of wood have also been investigated both at the cell wall level (Yu et al 2011) and at the macroscopic level (Ishimaru et al 2001;Sudijono et al 2004).…”

“…Since then, this technique has found many more applications in the area of wood science and technology, including wood development (Gindl et al 2004), wood fiber composites (Lee et al 2007), and wood adhesion (Konnerth et al 2006(Konnerth et al , 2007. The mechanical testing at the macroscopic level involved the investigation of the compressive modulus of elasticity (CMOE), which is thought to be related to some extent to the cell wall indentation modulus obtained through nanoindentation testing (Yu et al 2011).…”

Influence of the Mechanical Properties of Tobacco Stalk Fiber Cell Wall on Particleboard Panels

“…Consequently, if the mechanical properties of fiber cell wall are low and the fiber cell wall is easy to be compressd, the mechanical properties of the fiber itself can be retained and a good interface between the resin and fiber may be formed more easily. If the moisture content (MC) of particles is too low, it can reduce the physical and mechanical properties of particleboard while the mechanical properties of fiber cell wall are increased as the MC of fiber cell wall is reduced [22]. Otherwise, the fiber cell walls are hard to be compressd and the mechanical properties of the fiber itself [23] are not retained, reducing the mechanical properties of the resulting particleboard panels.…”