Three size-fractionated samples of pine beetle-killed wood particles were used to prepare lightweight insulative foams. The foams were produced by foam-forming an aqueous slurry containing wood particles (125–1000 μm), a polymer binder, and surfactant, followed by oven drying. The effect of wood particle size on the aqueous foam stability, structure, and performance of insulative foams was investigated. While all aqueous foams were highly stable, aqueous foam stability increased with decreasing particle size. For dry foams, the cell size distribution was similar for all particle sizes as it was primarily controlled by the surfactant; differences occurred within the cell wall structure. A size-structure-property relationship was identified using x-ray micro-computed tomography where smaller particles produced lighter cell wall frameworks, leading to lower densities and decreased thermal conductivity and compressive strength. Larger particles produced denser cell wall frameworks that were more resistant to deformation, although all dry foams had sufficient mechanical properties for use as insulation panels. Thermal conductivity for all wood particle size-fractionated samples was <0.047 W m K making the foams similar to expanded polystyrene/polyurethane and supporting their use as thermal insulation in buildings.

中文翻译：

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水性和干性隔热泡沫中木颗粒的尺寸-结构-性能关系

使用三种尺寸分级的松甲虫杀死的木材颗粒样品来制备轻质绝缘泡沫。泡沫是通过使含有木颗粒（125-1000μm）、聚合物粘合剂和表面活性剂的水浆形成泡沫，然后进行烘干而生产的。研究了木材颗粒尺寸对水性泡沫稳定性、结构和保温泡沫性能的影响。虽然所有水性泡沫都高度稳定，但水性泡沫的稳定性随着粒径的减小而增加。对于干泡沫，所有粒径的泡孔尺寸分布都相似，因为它主要由表面活性剂控制；差异发生在细胞壁结构内。使用 X 射线微计算机断层扫描确定了尺寸-结构-性能关系，其中较小的颗粒产生较轻的细胞壁框架，导致密度较低、导热性和抗压强度降低。尽管所有干泡沫都具有足够的机械性能用作隔热板，但较大的颗粒产生更致密的细胞壁框架，更能抵抗变形。所有木材颗粒尺寸分级样品的导热率均<0.047 W·m·K，使得泡沫与发泡聚苯乙烯/聚氨酯相似，并支持它们在建筑物中用作隔热材料。