Chen Guoliang, Liu Jian, Zhang Wei, Han Yanming, Zhang Derong, Li Jianzhang, Zhang Shifeng
Key Laboratory of Wood-Based Materials Science and Utilization, Beijing Forestry University, No. 35 Tsinghua East Road, Haidian District, Beijing 100083, China.
Beijing Key Laboratory of Wood Science and Engineering, Beijing Forestry University, No. 35 Tsinghua East Road, Haidian District, Beijing 100083, China.
Polymers (Basel). 2021 Mar 28;13(7):1068. doi: 10.3390/polym13071068.
Phenolic foams (PFs) are lightweight (<200 kg/m), high-quality, and inexpensive thermal insulation materials whose heat and fire resistance are much better than those of foam plastics such as polyurethane and polystyrene. They are especially suitable for use as insulation in chemical, petroleum, construction, and other fields that are prone to fires. However, PFs have poor mechanical properties, poor abrasion resistance, and easy pulverization. In this paper, a polyurethane prepolymer was treated with an isocyanate, and then the isocyanate-terminated polyurethane prepolymer and poplar powder were used to prepare modified lignin-based phenolic foams (PUPFs), which improved the abrasion resistance and decreased the pulverization of the foam. The foam composites were comprehensively evaluated by characterizing their chemical structures, surface morphologies, mechanical properties, thermal conductivities, and flame-retardant properties. The pulverization ratio was reduced by 43.5%, and the thermal insulation performance and flame-retardancy (LOI) were improved. Compared with other methods to obtain lignin-based phenolic foam composites with anti-pulverization and flame-retardant properties, the hybrid reinforcement of foam composites with an isocyanate-terminated polyurethane prepolymer and poplar powder offers a novel strategy for an environmentally friendly alternative to the use of woody fibers.
酚醛泡沫（PFs）是轻质（<200 kg/m³）、高质量且价格低廉的保温材料，其耐热性和耐火性远优于聚氨酯和聚苯乙烯等泡沫塑料。它们特别适合用作化学、石油、建筑等易发生火灾领域的保温材料。然而，PFs的机械性能较差、耐磨性差且易粉碎。本文用异氰酸酯对聚氨酯预聚物进行处理，然后用异氰酸酯封端的聚氨酯预聚物和杨木粉制备改性木质素基酚醛泡沫（PUPFs），提高了泡沫的耐磨性并减少了其粉碎性。通过对泡沫复合材料的化学结构、表面形貌、机械性能、热导率和阻燃性能进行表征，对其进行了综合评价。粉碎率降低了43.5%，保温性能和阻燃性（极限氧指数）得到了提高。与其他获得具有抗粉碎和阻燃性能的木质素基酚醛泡沫复合材料的方法相比，用异氰酸酯封端的聚氨酯预聚物和杨木粉对泡沫复合材料进行混合增强，为使用木质纤维提供了一种环保替代方案的新策略。
