Hygrothermal processes are widely used in modification of wood or other lignocellulosic materials to improve their decay resistance and dimensional stability. However, the mechanism behind the improved decay resistance is still unclear. In this study, hygrothermal modification of holocellulose was carried out at different temperature (℃) -duration (min) combinations (180−60, 220−60, 220−180), and the formation of pseudo lignin in modified holocellulose was verified. Its yield, as indicated by the acid insoluble substance, increased with the intensity of the hygrothermal modification from 0.11% for untreated holocellulose to 3.85%, 24.13%, and 65.86% for 180–60, 220–60, 220–180, respectively. According to the results of HPLC, FTIR, solid ¹³C NMR, ³¹P NMR, XRD and Py-GC-MS, the formed pseudo lignin contains polyfuran, aromatic, carbonyl and aliphatic structures. The formation pathway of pseudo lignin was proposed. It exhibited a significant inhibition effect against Gloeophyllum trabeum (brown rot fungus) with reduced mass losses from 6.89% for untreated holocellulose to 6.43%, 1.09% and 0.03% for 180–60, 220–60, 220–180, respectively; however, the inhibition effect against Coriolus versicolor (white rot fungus) was much less obvious. This provides an innovative point of view to explain the fungal degradation behavior of thermally modified wood or other carbohydrate materials.

湿热法广泛用于木材或其他木质纤维素材料的改性，以提高其耐腐性和尺寸稳定性。然而，提高抗衰变能力背后的机制仍不清楚。本研究在不同温度（℃）-持续时间（min）组合（180-60、220-60、220-180）下对全纤维素进行湿热改性，验证了改性全纤维素中假木质素的形成。如酸不溶性物质所示，其收率随着湿热改性的强度从未处理的全纤维素的 0.11% 分别增加到 180-60、220-60、220-180 的 3.85%、24.13% 和 65.86%。根据 HPLC、FTIR、固体¹³ C NMR、³¹P NMR、XRD和Py-GC-MS，形成的假木质素含有聚呋喃、芳香族、羰基和脂肪族结构。提出了假木质素的形成途径。它对Gloeophyllum trabeum（褐腐真菌）表现出显着的抑制作用，质量损失从未处理的全纤维素的 6.89% 分别降低到 180-60、220-60、220-180 的 6.43%、1.09% 和 0.03%；然而，对云芝（白腐菌）的抑制作用则不那么明显。这提供了一个创新的观点来解释热改性木材或其他碳水化合物材料的真菌降解行为。