Yang Tianjiao, Pizzi Antonio, Xi Xuedong, Zhou Xiaojian, Zhang Qianyu
Yunnan Key Laboratory of Wood Adhesives and Glued Products, College of Material Science and Chemistry Engineering, Southwest Forestry University, Kunming 650224, China.
LERMAB, University of Lorraine, 27 Rue Philippe Seguin, 88000 Epinal, France.
Polymers (Basel). 2024 Oct 15;16(20):2899. doi: 10.3390/polym16202899.
The preparation and application of non-isocyanate polyurethane (NIPU) from biomass raw materials as a substitute for traditional polyurethane (PU) has recently become a research hot topic as it avoids the toxicity and moisture sensitivity of isocyanate-based PU. In the work presented here, self-blowing GNIPU non-isocyanate polyurethane (NIPU) rigid foams were prepared at room temperature, based on glucose, with acids as catalysts and glutaraldehyde as a cross-linker. The effects of different acids and glutaraldehyde addition on foam morphology and properties were investigated. The water absorption, compressive resistance, fire resistance, and limiting oxygen index (LOI) were tested to evaluate the relevant properties of the foams, and scanning electron microscopy (SEM) was used to observe the foams' cell structure. The results show that all these foams have a similar apparent density, while their 24 h water absorption is different. The foam prepared with phosphoric acid as a catalyst presented a better compressive strength compared to the other types prepared with different catalysts when above 65% compression. It also presents the best fire resistance with an LOI value of 24.3% (great than 22%), indicating that it possesses a good level of flame retardancy. Thermogravimetric analysis also showed that phosphoric acid catalysis slightly improved the GNIPU foams' thermal stability. This is mainly due to the flame-retardant effect of the phosphate ion. In addition, scanning electron microscopy (SEM) results showed that all the GNIPU foams exhibited similar open-cell morphologies with the cell pore sizes mainly distributed in the 200-250 μm range.
以生物质原料制备非异氰酸酯聚氨酯（NIPU）并将其作为传统聚氨酯（PU）的替代品，近来已成为一个研究热点，因为它避免了异氰酸酯基PU的毒性和对水分的敏感性。在本文所述的工作中，基于葡萄糖，以酸为催化剂、戊二醛为交联剂，在室温下制备了自发泡的GNIPU非异氰酸酯聚氨酯硬质泡沫。研究了不同酸和戊二醛添加量对泡沫形态和性能的影响。测试了吸水率、抗压强度、耐火性和极限氧指数（LOI）以评估泡沫的相关性能，并使用扫描电子显微镜（SEM）观察泡沫的泡孔结构。结果表明，所有这些泡沫具有相似的表观密度，但其24小时吸水率不同。与用不同催化剂制备的其他类型泡沫相比，以磷酸为催化剂制备的泡沫在压缩率高于65%时表现出更好的抗压强度。它还具有最佳的耐火性，LOI值为24.3%（大于22%），表明它具有良好的阻燃性。热重分析还表明，磷酸催化略微提高了GNIPU泡沫的热稳定性。这主要是由于磷酸根离子的阻燃作用。此外，扫描电子显微镜（SEM）结果表明，所有GNIPU泡沫均呈现相似的开孔形态，泡孔尺寸主要分布在200 - 250μm范围内。
