Chemical characterisation and durability enhancement of kapok wood using Ivorian plant extracts

The study investigated the impact of sapwood proportion in different sawdust mixtures composed of sapwood and heartwood from five durable Ivorian wood species Mansonia altissima (bete), Nauclea diderrichii (badi), Milicia excelsa (iroko), M. regia (iroko), and Khaya ivorensis (acajou) as well as the ability of hydroethanolic extracts derived from these sawdust’s to confer enhanced durability to Ceiba pentandra (kapok), a naturally low-durability species. In vitro tests were conducted to assess the antifungal efficacy of the extracts by measurng the mass loss of wood samples exposed to lignivorous fungi. Extracts from bete, badi, and both iroko species showed the best performance, with mass losses below 35%, thereby improving the durability of kapok wood from “non-durable” to “moderately durable.” Although less effective, acajou extracts also reduced biodeterioration compared to untreated samples. Under field conditions, the conferred durability varied with the wood species, the origin of the extract, and the product retention in the wood. Heartwood extracts, particularly from bete and badi, resulted in the lowest mass losses, indicating higher concentrations of bioactive compounds. Higher retention levels (>14 kg/m³) generally enhanced resistance, suggesting that conferred durability depends on both the intrinsic antifungal activity and the stability of the extracts within the wood matrix.