Effects of Biological and Chemical Degradation on the Properties of Scots Pine Wood—Part I: Chemical Composition and Microstructure of the Cell Wall

Abstract

Research on new conservation treatment for archaeological wood requires large amounts of wooden material. For this purpose, artificial wood degradation (biological—using brown-rot fungus Coniophora puteana, and chemical—using NaOH solution) under laboratory conditions was conducted to obtain an abundance of similar samples that mimic naturally degraded wood and can serve for comparative studies. However, knowledge about its properties is necessary to use this material for further study. In this study, the chemical composition and microstructure of degraded cell walls were investigated using FT-IR, XRD, helium pycnometry and nitrogen absorption methods. The results show that biological degradation caused the loss of hemicelluloses and celluloses, including the reduction in cellulose crystallinity, and led to lignin modification, while chemical degradation mainly depleted the amount of hemicelluloses and lignin, but also affected crystalline cellulose. These changes affected the cell wall microstructure, increasing both surface area and total pore volume. However, the chemical degradation produced a greater number of mesopores of smaller size compared to fungal decomposition. Both degradation processes weakened the cell wall’s mechanical strength, resulting in high shrinkage of degraded wood during air-drying. The results of the study suggest that degraded wood obtained under laboratory conditions can be a useful material for studies on new consolidants for archaeological wood.

Effect of lignin in cellulose nanofibers on biodegradation and seed germination

“…These processes are used to increase the biodegradation rate of known recalcitrant materials such as biosourced poly(lactic acid) [51], synthetic plastics like polyethylene [52], and provide reason to the biodegradation rate of fatty acid surfactants [53]. Non-carboxylated pine wood powder (< 0.2 mm) exhibited 38.5% biological degradation over 8 weeks [54], which is comparable to the biodegradation rates of nanofibers used in this study. Therefore, succinylation does not oppose the effect of lignin on the biodegradation of nanocellulose enough to be a major factor affecting these properties.…”

Effects of Biological and Chemical Degradation on the Properties of Scots Pine—Part II: Wood-Moisture Relations and Viscoelastic Behaviour

“…P. Karst BAM 112 (BAM Ebw. 15) was used (resulted in about 38.5% mass loss), while chemical degradation was performed by soaking wood samples in 50% NaOH solution (mass loss of about 17%), as described in Part I [4].…”

“…In order to achieve this, broad research is needed, which demands large amounts of material. It is impossible to obtain enough archaeological wood with similar properties for extensive studies on new conservation agents, hence the idea to use artificially (biologically and chemically) degraded wood that mimics naturally degraded archaeological one [1][2][3][4]. However, detailed knowledge about the material's properties is necessary to interpret the results of further research on new conservation agents correctly.…”

“…In the first step of the research (Part I [4]), the changes in the chemical composition and cell wall microstructure produced by biological and chemical degradation were investigated. The present research aimed to determine how those changes affected the wood moisture and rheological properties in order to supplement the characteristics of degraded wooden material.…”

Decay level classification of wooden components in Tingbao Yang’s former residence utilizing polarization and fluorescence effects

“…Although preservation efforts have been ongoing for Tingbao Yang's former residence, the key load-bearing wooden components, such as columns, beams, lintels, purlins, and rafters, have suffered extensive deterioration, worm damage, and cracks. The degradation of wood inevitably leads to alterations in the anatomical structure of wood cell walls and degradation of chemical components (Cavallaro et al 2017;Tamburini et al 2017;Bari et al , 2020Dong et al 2020;Yang et al 2020Yang et al , 2021aYang et al ,b, 2022aBroda et al 2022). As the degree of deterioration increases, there is a noticeable attenuation in the physical and mechanical properties (Brischke et al 2019;Ueda et al 2020).…”