ABSTRACT

In this research, a sandwich panel with particleboard as surface layers and rigid polyurethane (PU) foam as core layers (foam-core particleboard) was produced with a one-step in situ foaming process. The effects of hydrofluorocarbon concentration as the blowing agent (BA) on the foam features and physical and mechanical properties of the produced panels were investigated. Typical micrograph of the rigid PU foam showed well-defined closed cells of spherical and polyhedral shapes. It was shown that the number of fractured cells in the foam structure was increased with the addition of BA in the amount of more than 4.5%. The results showed that the bending strength and internal bond values significantly raised with increasing BA concentration up to 6%. Screw withdrawal resistance from the face and thickness swelling were not significantly changed while the BA concentration varied. Edge screw withdrawal resistance and water absorption were drastically decreased when the blowing agent concentration was raised in the whole studied range.

ABBREVIATIONS: PU: polyurethane; OH: hydroxyl; PO: polyol; ISO: isocyanate; BA: blowing agent; PMDI: polymeric methylene diphenyl diisocyanate; BS: bending strength; IB: internal bond; SWR: screw withdrawal resistance; TS: thickness swelling; WA: water absorption

抽象的

在这项研究中，以一步法原位生产了以刨花板为表面层和硬质聚氨酯（PU）泡沫为芯层（泡沫芯刨花板）的夹芯板发泡过程。研究了氢氟碳化合物作为发泡剂（BA）的浓度对所生产板材的泡沫特征以及物理和机械性能的影响。硬质PU泡沫的典型显微照片显示球形和多面体形状的定义明确的闭孔。结果表明，当BA的加入量大于4.5％时，泡沫结构中的破裂小孔数目增加。结果表明，随着BA浓度增加到6％，弯曲强度和内部键合值显着提高。当BA浓度变化时，螺丝从表面的抗拔出力和厚度膨胀没有显着变化。

缩写：PU：聚氨酯；OH：羟基；PO：多元醇；ISO：异氰酸酯；BA：发泡剂；PMDI：聚合亚甲基二苯基二异氰酸酯；BS：弯曲强度；IB：内部债券；SWR：螺丝拔出阻力；TS：厚度膨胀；WA：吸水率