Pine Wood Treated with a Citric Acid and Glycerol Mixture: Biomaterial Performance Improved by a Bio-byproduct

Abstract

Wood material is a good reservoir for biogenic carbon storage. The use of wood material for outdoor products such as siding in the building construction sector presents limits. These limits are bound to the nature of wood material (hygroscopic property and anatomical structure). They are responsible for the dimensional variation associated with moisture content variations. Fungal attacks and coating layers adhesion on wood surface, are other problems. This research investigated the feasibility of impregnation with environmentally friendly chemicals, i.e., a citric acidglycerol mixture (CA-G). The anti-swelling efficiency (ASE), hardness, biodegradation, and coating adhesion tests were performed on softwood specimens. ASE results were up to 53%. The equilibrium moisture content of the treated specimens was less than half of the untreated ones. FTIR spectroscopy showed bands at 1720 to 1750 cm -1 , indicating the presence of ester bonds, and scanning electron microscopy images confirmed the polymerization and condensation of treatment solution inside the wood structure. Hardness and decay resistance were increased; however, treatment reduces coating adhesion. In conclusion, CA-G represents a promising eco-responsible solution for improving the technical performance of outdoor wood products.

A Review on Citric Acid as Green Modifying Agent and Binder for Wood

“…Logically, modified wood is expected to possess longer service life expectancy compared to that of the untreated wood and subsequently lower maintenance requirements [18]. This is owing to the fact that modified wood is normally bestowed with enhanced technological performance [91], reduced hygroscopicity, and improved durability after treatment [91,92]. There is only one study regarding the environment impacts of CA-treated wood found.…”

Macrobiological Degradation of Esterified Wood with Sorbitol and Citric Acid

“…Several studies have used citric acid and glycerol for wood protection. Essoua et al [21] and L'Hostis et al [22] observed, among other properties, improved mechanical properties and better protection against fungal decay. Berube et al [23] found that the use of acid catalysts resulted in higher levels of polymerization.…”

Beech wood modification based on in situ esterification with sorbitol and citric acid

“…Under practical conditions, this technique can be applied to two types of wood modification, wood esterification and esterification-based bulk impregnation (Hill 2011). In wood esterification, the reaction is commonly based on the reaction of anhydride/carboxylic acid/isocyanate/ester groups of a modifying agent (chemical) and hydroxyl groups of wood (Rowell 1983;Hill et al 2007), while in esterification-based bulk impregnation, esterification is usually based on the reaction of anhydride/carboxylic acid/isocyanate groups of one modifying agent and hydroxyl groups from other modifying agents/and wood (Essoua et al 2016;Mubarok et al 2016;Berube et al 2017;L'hostis et al 2017;Larnøy et al 2018). Even though both techniques work with the same principle as the formation of ester bonds, in terms of the modified wood properties, they show different characteristics.…”