Environmentally Benign Wood Modifications: A Review

Abstract

Wood modification, an efficient approach to enhance the intrinsic properties of wood, has been extensively studied for decades. Due to growing environmental awareness, the sustainability of wood modification has received more attention. Generally, the sustainability in wood modification should consist of three aspects: an environmentally friendly processes, renewable modifying agents, and nontoxic and biodegradable resultant products. Recently, some biobased modifying agents obtained from renewable feedstocks were explored for substituting the petroleum-based ones. This review focuses on representative wood modification methods, including furfurylation, impregnation with natural products and biodegradable polymers, and chemical modification with sustainable reagents, since these methods have the potential to enhance wood properties. However, there are many challenges for using these agents, including effectiveness in penetration, evenness in distribution, and durability. The cost, process conditions, and equipment of these methods could also be challenges for scaling up. In addition, current studies mainly pay attention to the green reagent selection and property enhancement, rather than environment behavior evaluation of the resultant products. Effort should be made to evaluate the ecotoxicity and degradation behavior of the modified wood since it can help us determine whether the new formulations are sustainable. Much work needs to be done to overcome the obstacles above-mentioned and to develop efficient modification methods with a minimum environmental impact.

Delignified Wood from Understanding the Hierarchically Aligned Cellulosic Structures to Creating Novel Functional Materials: A Review

“…However, recent review articles have only briefly discussed DWbased functional materials (e.g., transparent wood) [37,13] and their potential applications (e.g., membranes for electronics, biological applications, and wastewater treatments). [24,35,39] Some other recent review articles have focused on environmentally friendly wood modifications, [41] and wood-carbides composites, [42] and other biopolymeric based processing of wood. [43] Rongpipi et al [44] reviewed the latest developments and techniques used for cellulose characterization of structure and interactions of cellulose in plant cell walls, particularly cellulose crystallinity, microfibril size, and spatial organization along with cellulose-cellulose and cellulose-matrix interactions.…”

“…However, recent review articles have only briefly discussed DW‐based functional materials (e.g., transparent wood) [ 37,13 ] and their potential applications (e.g., membranes for electronics, biological applications, and wastewater treatments). [ 24,35,39 ] Some other recent review articles have focused on environmentally friendly wood modifications, [ 41 ] and wood–carbides composites, [ 42 ] and other biopolymeric based processing of wood. [ 43 ] Rongpipi et al.…”

Characterization of Microstructure, Chemical, and Physical Properties of Delignified and Densified Poplar Wood

“…Increasing wood utilization through conservation not only can reduce the carbon footprint but promote sustainable and healthy forest management. Wood treatments through the thermal process [ 2 ] and resin impregnation [ 3 ] have been common practices to improve the dimensional stability and durability of wood; nevertheless, considerable disadvantages remain, including harmful reagents and difficulties at the end of life [ 3 , 4 , 5 ]. Specifically, the densification through hydro-thermo treatment has also been applied to improve wood mechanical strength, especially for woods with low densities, such as fast-growing and small-diameter trees in overpopulated forests.…”

Sustainability in wood materials science: an opinion about current material development techniques and the end of lifetime perspectives

“…This was demonstrated with several oil-based monomers including styrene and various acrylates, which provided wood with excellent new properties [16,17]. To avoid the use of non-renewable resources, the addition of biopolymers, and in particular polyesters was investigated [40]. Many different polymers could be added to wood, including poly(lactic acid) (PLA), polycaprolactone (PCL) or poly(glycolic acid) (PGA), with acceptable results, mitigated by the complexity of the polymerization process inside wood.…”