中图分类号：TS658；TQ320.63 文献标识码：A DOI：10.7525/j.issn.1006-8023.2025.04.008

Abstract：This studyinvestigatedtheporefractalcharacteristicsofmediumdensity fiberboard（MDF）of diferentthicknesses.By combining high-pressure mercury intrusion porosimetry （MIP） and nitrogen （ N₂ ）adsorption experiments， the pore structure parameters such as pore volume，pore size，and pore size distribution were quantified.Utilizing the FHH（Frenkel-Halsey-Hill）andMIPfractal theoretical models inconjunction with experimental results，the fractal dimensions of pores at diferent scales werecalculated.Thecomplexityof the pore structure was quantified through fractal models，revealingsignificantdiferences inthepore fractalcharacteristicsofMDFofdiffrentthicknesses.Thefractal dimensions calculated using thefractal models indicated that both the macro-pore fractal dimension（2.957-2.988）and the mesopore fractal dimension （2.602-2.851） increased significantly with increasing thickness （ R²gt;0.90 ）， suggesting that the pore structurecomplexityof thickerboardswas higher.The influenceof density（O.722-O.777 g/cm³）on the fractal dimension was relativelyweak．Moreover，there wasa closerelationship betweenthefractal dimensionand pore structure parameters.The macro-pore fractal dimension was positivelycorelated with the average pore size and porosity of the material，whilethe mesopore fractaldimension was negativelycorelated with theaverage pore sizeand positively corelated with the specific surface area.This study reveals the pore fractal paterns dominated bythickness，providing a theoretical basis for optimizing the environmental performance of MDF through process improvement.

Keywords：MDF；pore; fractal dimension; high-pressure mercury intrusion；nitrogen adsorption

0 引言

随着我国经济的持续上升，建筑行业得到快速发展的同时，家具建材和室内装饰材料的需求也逐年攀升，木制人造板被广泛应用于其中。人造板中由木材和胶黏剂释放的挥发性有机化合物不仅会降低空气质量，还会严重危害人体健康。目前，有众多学者对人造板内部VOCs的释放开展了大量的研究工作，尤其在对不同人造板VOCs的定性与定量分析中取得了诸多成果[1-3]。VOCs在人造板内部的吸附、扩散和渗透等行为与板材孔隙结构息息相关，常见的孔隙结构参数有孔隙直径、平均孔径、比表面积和分形维数等，其中孔隙直径与分形维数 （D） 是量化多孔材料孔隙构造的重要指标。对于孔隙直径，国际纯粹与应用化学联合会（IUPAC）按其大小将多孔材料的孔隙分为宏观孔（ gt;50nm. 、介观孔0 （2～50nm） 以及微观孔 （lt;2nm）^[4] ;对于分形维数，其理论范围在2＼～3，分形维数越大，表明孔隙结构越复杂[5-7]

人造板的孔隙结构具有很强的不均一性，其内部构造纷繁复杂，常用的多孔材料表征手段主要包括高分辨率扫描电镜（high resolution scanning electron mi-croscope，HR-SEM）[8]、气体吸附法[9]、高压压汞法[10]和纳米 CT^[11] 等。许多学者已对多孔材料孔隙构造以及分形特征做出了大量研究，基于气体吸附等温曲线提出了多种分形维数计算方法，包括粒径法、分形BET（Brunauer-Emmett-Teller）模型、分形FHH（Frenkel-Halsy-Hill）模型和热力学算法[12-13]。此外，戴方尧[14]基于活性炭一类的非均质微孔吸附剂的研究，提出了微孔分形维数的计算模型。通过Menger海绵的构造思想同时结合Washburn公式可以建立压汞法的分形模型。……