Wood is a natural composite widely employed as a residential building interior finishing. Although wood is readily available and offers benefits to the occupants, such as enhanced well-being, it is rarely employed in commercial construction due, amongst others, to the potential hazard of fire propagation. The application of flame retardant (FR) treatments leads to a reduction of wood flammability and supports wood as interior finishing. Polyelectrolyte complexes (PECs) deposition is an innovative surface treatment that has already proven its efficiency for fabrics. For wood, recent studies have highlighted that the weight gain impacted the fire-retardancy, and a minimum of 2 wt.-% was set to obtain fire protection. This study explored the potential of surface delignification to activate the wood surface and facilitate the PEC impregnation. Yellow birch (Betula alleghaniensis, Britt.) was surface delignified (0.3 mm) using sodium chlorite. The treatment impact on wood was evaluated by spectroscopy analysis (FTIR, Raman), and the increase in wood wettability was demonstrated (contact angle decreases from 50° to 35° after the surface delignification). Then, PECs consisting of polyethyleneimine and sodium phytate were surface impregnated in wood and delignified wood. The flame retardancy was evaluated using a cone calorimeter. Despite the increase in weight gain (1.5 wt.-% ± 0.3 wt.-% to 4.3 wt.-% ± 2.5 wt.-%), fire performance was not improved. This study demonstrates that lignin strongly affects char formation, even in the presence of PECs.

中文翻译：

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表面脱木素对聚电解质复合物处理木材阻燃性能的影响

木材是一种天然复合材料，广泛用作住宅建筑的室内装饰。尽管木材很容易获得并且为居住者带来好处，例如增强福祉，但由于火灾蔓延的潜在危险等原因，它很少用于商业建筑。阻燃（FR）处理的应用可降低木材的可燃性，并支持木材作为室内装饰。聚电解质复合物 (PEC) 沉积是一种创新的表面处理方法，已证明其对织物的有效性。对于木材，最近的研究强调重量增加会影响阻燃性，并且至少设定 2 wt.-% 才能获得防火保护。本研究探讨了表面脱木质素活化木材表面并促进 PEC 浸渍的潜力。黄桦（阿勒根桦，Britt.）使用亚氯酸钠进行表面脱木素（0.3毫米）。通过光谱分析（FTIR、拉曼）评估处理对木材的影响，并证明木材润湿性的增加（表面脱木质素后接触角从 50° 减小到 35°）。然后，将由聚乙烯亚胺和植酸钠组成的PECs表面浸渍在木材和脱木素木材中。使用锥形量热计评价阻燃性。尽管重量增加了（1.5 wt.-% ± 0.3 wt.-% 至 4.3 wt.-% ± 2.5 wt.-%），但防火性能并未改善。这项研究表明，即使存在 PEC，木质素也会强烈影响炭的形成。