Mirski Radosław, Dukarska Dorota, Walkiewicz Joanna, Derkowski Adam
Department of Wood Based Materials, Faculty of Forestry and Wood Technology, Poznań University of Life Sciences, Wojska Polskiego 38/42, 60-627 Poznań, Poland.
Materials (Basel). 2021 Aug 24;14(17):4781. doi: 10.3390/ma14174781.
A significant part of the work carried out so far in the field of production of biocomposite polyurethane foams (PUR) with the use of various types of lignocellulosic fillers mainly concerns rigid PUR foams with a closed-cell structure. In this work, the possibility of using waste wood particles (WP) from primary wood processing as a filler for PUR foams with open-cell structure was investigated. For this purpose, a wood particle fraction of 0.315-1.25 mm was added to the foam in concentrations of 0, 5, 10, 15 and 20%. The foaming course of the modified PUR foams (PUR-WP) was characterized on the basis of the duration of the process' successive stages at the maximum foaming temperature. In order to explain the observed phenomena, a cellular structure was characterized using microscopic analysis such as SEM and light microscope. Computed tomography was also applied to determine the distribution of wood particles in PUR-WP materials. It was observed that the addition of WP to the open-cell PUR foam influences the kinetics of the foaming process of the PUR-WP composition and their morphology, density, compressive strength and thermal properties. The performed tests showed that the addition of WP at an the amount of 10% leads to the increase in the PUR foam's compressive strength by 30% (parallel to foam's growth direction) and reduce the thermal conductivity coefficient by 10%.
到目前为止，在使用各种木质纤维素填料生产生物复合聚氨酯泡沫（PUR）领域所开展的工作，很大一部分主要涉及具有闭孔结构的硬质PUR泡沫。在这项工作中，研究了将初级木材加工产生的废木颗粒（WP）用作具有开孔结构的PUR泡沫填料的可能性。为此，将粒径为0.315 - 1.25毫米的木颗粒以0%、5%、10%、15%和20%的浓度添加到泡沫中。基于在最高发泡温度下该过程连续阶段的持续时间，对改性PUR泡沫（PUR - WP）的发泡过程进行了表征。为了解释所观察到的现象，使用扫描电子显微镜（SEM）和光学显微镜等微观分析方法对泡孔结构进行了表征。还应用计算机断层扫描来确定木颗粒在PUR - WP材料中的分布。观察到向开孔PUR泡沫中添加WP会影响PUR - WP组合物的发泡过程动力学及其形态、密度、抗压强度和热性能。所进行的测试表明，添加10%的WP会使PUR泡沫的抗压强度（平行于泡沫生长方向）提高30%，并使导热系数降低10%。
