Han Shibo, Huang Guangying, Han Han, Yan Xilai, Xie Jie, He Hongshen, Mondal Ajoy Kanti, Lin Weijie, Huang Fang
College of Material Engineering, Fujian Agriculture and Forestry University, Fuzhou 350108, Fujian, China.
Institute of National Analytical Research and Service, Bangladesh Council of Scientific and Industrial Research, Dhanmondi, Dhaka 1205, Bangladesh.
Int J Biol Macromol. 2025 Apr;302:140370. doi: 10.1016/j.ijbiomac.2025.140370. Epub 2025 Feb 1.
Currently, most polyols used in polyurethane foam (PUF) synthesis are derived from petrochemicals. However, lignin as the most abundant aromatic biopolymer rich in hydroxyl groups, is a suitable filler for synthesizing polyurethane foam. Therefore, in this study, Kraft lignin (KL) was utilized as a partial substitute for flexible polyethylene glycol 400 (PEG400). After adding 15 % KL, NaCl was introduced as a medium for synthesizing LFPUF and Polydimethylsiloxane (PDMS) was used as a foam stabilizer. Lignin-based flexible polyurethane foam (LFPUF) with high elasticity was synthesized. The aromatic ring structure of KL acted as a reinforcement for the foam, while the flexible PEG400 provided excellent flexibility to LFPUF. Na interacts with oxygen atoms in the long chain of PEG to form a cyclic crown ether structure. This promotes proximity and ordering of the hydroxyl groups, thereby facilitating proton transfer and optimising the cell size of the foam. Ultimately, the foam synthesized with 3 % NaCl (LFPUF-3%NaCl) exhibited an average cell size and hole size of 484.1 and 183.6 μm, respectively, significantly smaller than those of the foam synthesized without NaCl (843.5 and 249.3 μm, respectively). The foam resilience and elastic recovery of LFPUF-3%NaCl were 39.56 and 99.03 %, respectively, which was higher than that of the foam synthesized without NaCl (20.36 % and 97.08 %, respectively). In addition, LFPUF-3%NaCl maintained a high elastic recovery of 97.61 % after 20 cycles of compression. The egg drop test demonstrated that the foam effectively provided protective cushioning for fragile items.
目前，用于合成聚氨酯泡沫（PUF）的大多数多元醇都来源于石化产品。然而，木质素作为含量最丰富且富含羟基的芳香族生物聚合物，是合成聚氨酯泡沫的合适填料。因此，在本研究中，硫酸盐木质素（KL）被用作柔性聚乙二醇400（PEG400）的部分替代品。添加15%的KL后，引入氯化钠作为合成木质素基柔性聚氨酯泡沫（LFPUF）的介质，并使用聚二甲基硅氧烷（PDMS）作为泡沫稳定剂。合成了具有高弹性的木质素基柔性聚氨酯泡沫（LFPUF）。KL的芳香环结构对泡沫起到增强作用，而柔性的PEG400为LFPUF提供了优异的柔韧性。钠与PEG长链中的氧原子相互作用形成环状冠醚结构。这促进了羟基的接近和有序排列，从而有利于质子转移并优化泡沫的泡孔尺寸。最终，用3%氯化钠合成的泡沫（LFPUF - 3%NaCl）的平均泡孔尺寸和孔径分别为484.1和183.6μm，明显小于未添加氯化钠合成的泡沫（分别为843.5和249.3μm）。LFPUF - 3%NaCl的泡沫回弹性和弹性回复率分别为39.56%和99.03%，高于未添加氯化钠合成的泡沫（分别为20.36%和97.08%）。此外，LFPUF - 3%NaCl在经过20次压缩循环后仍保持97.61%的高弹性回复率。鸡蛋掉落测试表明，该泡沫能有效地为易碎物品提供保护缓冲。
