A comparative study on the effects of linseed oil and shellac treatment on the hygroscopicity, dimensional stability, and color changes of Chinese ash wood

Abstract

Linseed oil and shellac are natural, environmentally friendly materials with good water repellency. They were used to impregnate Chinese ash wood at room temperature (20 °C) using a vacuum-pressure procedure (consisting of three cycles of 0.01 MPa for 1.5 h and atmospheric pressure for 1.5 h) to improve the dimensional stability of wood. The effects of the impregnation treatment on wood color changes, dimensional stability, moisture absorption, and morphological characteristics were evaluated. The linseed oil and shellac treatment improved the dimensional stability of wood. Linseed oil and shellac displayed good permeability in Chinese ash wood, with weight gains of 21.7% and 19.0%, respectively, after impregnation. The swelling coefficients of treated wood in the tangential and radial directions decreased by 15 to 22%, indicating that impregnation improved the dimensional stability of wood. Linseed oil and shellac solidified and occluded the pits within the wood interior to prevent moisture absorption. This method can be used to improve the dimensional stability of a variety of wood products, such as buildings, furniture, and landscape architecture.

Coating Process Optimization and Self-Healing Performance Evaluation of Shellac Microcapsules Coated with Melamine/Rice Husk Powder

“…It also can improve the mechanical properties of the coating on wooden substrate by extending the threshold of resistance to force and prolonging the self-healing time as a result of the good toughness of rice husk powder [22][23][24], as the core material, the shellac, a natural material, is green and environmentally friendly. The shellac has some excellent characteristics, such as moisture resistance, antirust, embalming, oil protection, acid resistance, and strong binding [25][26][27], and has been widely applied to the surface remediation of wooden crafts and precious musical instruments [28][29][30]. Therefore, the application of shellac microcapsule coated with melamine/rice husk powder has positive exploration significance and practical value on modification waterborne coatings on wood surface.…”

Wood impregnation in relation to its mechanisms and properties enhancement

“…The type of waxes can be divided into several categories, including natural waxes such as beeswax (Li et al 2020) and carnauba wax (Chen et al 2020); natural fossil waxes derived from petroleum or lignite such as paraffin (Esteves et al 2014;Jiang et al 2020) and montan wax; synthetic such as hydrocarbon or amide waxes (Scholz et al 2010a). Meanwhile, the different kinds of oils that can be utilized as impregnating agents include linseed oil (Chen et al 2020;Liu et al 2020), tung oil (Ahmed et al 2017;He et al 2019), hemp oil (Baar et al 2021), engine oil (Belchinskaya et al 2021), becker oil (Ahmed et al 2017), vegetable oil (Wei et al 2022), and other plant oil-based substances (Vasiliauskiene et al 2020).…”

“…In addition, oils impregnation using vacuum-pressure method have been reported by other researchers (Table 1). Chen et al (2020) and Liu et al (2020), used linseed oil (LO) derived from seed of Linum usitatissimum as impregnating agents. Once entering the wood structure, LO can block the lumen and generate a stable LO film on the pore surface, thus limiting water uptake.…”

High-Strength, High-Swelling-Resistant, High-Sensitivity Hydrogel Sensor Prepared with Wood That Retains Lignin

“…The natural composition of wood exhibits good dimensional stability in both the tangential and radial directions. 23 Besides, the ray structure of wood provides radial support at the cellular level. 24 Importantly, lignin acts as an adhesive by cross-linking fibers and cells.…”