Abstract In this research cellulose nanofibers (CNF) were successfully extracted from rice straw through a chemomechanical method and then mixed with urea-formaldehyde (UF) adhesive for the production of medium density fiberboard (MDF). The industrial grade liquid urea-formaldehyde (UF) resin with formaldehyde: urea molar ratio of 1.15 was modified by adding 0.5, 1.5 and 2 wt % of nanofibrillated cellulose (CNF) based on UF resin solids. The morphology, gel time, viscosity, and the non-volatile solid content of the modified UF adhesive were investigated. Formaldehyde emission and some mechanical properties modulus of rupture (MOR), modulus of elasticity (MOE) and internal bond strength (IB)) of the resulting MDF panels were measured. Solids content and viscosity of the UF adhesive decreased while gel time increased by mixing CNF with the resin. The formaldehyde emission of the panels made with UF containing CNF was lower than that of the panels made from neat UF while MOR, MOE and IB values increased by increasing the CNF content in the panels.

中文翻译：

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从稻草中提取的纤维素纳米纤维添加到脲醛树脂中；对粘合特性和中密度纤维板性能的影响

摘要 本研究通过化学机械法从稻草中成功提取纤维素纳米纤维（CNF），然后与脲醛（UF）粘合剂混合制备中密度纤维板（MDF）。通过添加基于 UF 树脂固体的 0.5、1.5 和 2 wt% 的纳米原纤化纤维素 (CNF)，对甲醛：尿素摩尔比为 1.15 的工业级液态脲醛 (UF) 树脂进行改性。研究了改性超滤胶的形态、凝胶时间、粘度和不挥发固体含量。测量了所得 MDF 面板的甲醛释放量和一些机械性能的断裂模量 (MOR)、弹性模量 (MOE) 和内部粘合强度 (IB)。通过将 CNF 与树脂混合，UF 粘合剂的固含量和粘度降低，而凝胶时间增加。