Zhan Jing, Mao Liangchen, Qin Rongshui, Qian Jing, Mu Xiaowei
School of Civil Engineering, Anhui Jianzhu University, Hefei 230601, China.
School of Environment and Energy Engineering, Anhui JianZhu University, Hefei 230601, China.
Materials (Basel). 2024 Jul 13;17(14):3473. doi: 10.3390/ma17143473.
Biomass has been widely used due to its environmental friendliness, sustainability, and low toxicity. In this study, aminophosphorylated cellulose (PNC), a biomass flame retardant containing phosphorus and nitrogen, was synthesized by esterification from cellulose and introduced into polyurethane to prepare flame-retardant rigid polyurethane foam. The combustion properties of the PU and PU/PNC composites were studied using the limiting oxygen index (LOI), UL-94, and cone calorimeter (CCT) methods. The thermal degradation behavior of the PU and PU/PNC composites was analyzed by thermogravimetric analysis (TGA) and thermogravimetric infrared spectroscopy (TG-IR). The char layer after combustion was characterized using SEM, Raman, and XPS. The experimental results showed that the introduction of PNC significantly improved the flame-retardant effect and safety of PU/PNC composites. Adding 15 wt% PNC to PU resulted in a vertical burning grade of V-0 and a limiting oxygen index of 23.5%. Compared to the pure sample, the residual char content of PU/PNC15 in a nitrogen atmosphere increased by 181%, and the total heat release (THR) decreased by 56.3%. A Raman analysis of the char layer after CCT combustion revealed that the ID/IG ratio of PU/PNC15 decreased from 4.11 to 3.61, indicating that the flame retardant could increase the stability of the char layer. The TG-IR results showed that PNC diluted the concentration of O and combustible gases by releasing inert gases such as CO. These findings suggest that the developed PU/PNC composites have significant potential for real-world applications, particularly in industries requiring enhanced fire safety, such as construction, transportation, and electronics. The use of PNC provides an eco-friendly alternative to traditional flame retardants. This research paves the way for the development of safer, more sustainable, and environmentally friendly fire-resistant materials for a wide range of applications.
生物质因其环境友好性、可持续性和低毒性而被广泛使用。在本研究中，通过纤维素的酯化反应合成了一种含磷和氮的生物质阻燃剂——氨基磷酸化纤维素（PNC），并将其引入聚氨酯中制备阻燃硬质聚氨酯泡沫。采用极限氧指数（LOI）、UL-94和锥形量热仪（CCT）方法研究了PU和PU/PNC复合材料的燃烧性能。通过热重分析（TGA）和热重红外光谱（TG-IR）分析了PU和PU/PNC复合材料的热降解行为。使用扫描电子显微镜（SEM）、拉曼光谱和X射线光电子能谱（XPS）对燃烧后的炭层进行了表征。实验结果表明，PNC的引入显著提高了PU/PNC复合材料的阻燃效果和安全性。向PU中添加15 wt%的PNC可使垂直燃烧等级达到V-0，极限氧指数为23.5%。与纯样品相比，PU/PNC15在氮气气氛中的残炭含量增加了181%，总热释放（THR）降低了56.3%。对CCT燃烧后的炭层进行拉曼分析表明，PU/PNC15的ID/IG比值从4.11降至3.61，表明该阻燃剂可提高炭层的稳定性。TG-IR结果表明，PNC通过释放CO等惰性气体稀释了O和可燃气体的浓度。这些发现表明，所开发的PU/PNC复合材料在实际应用中具有巨大潜力，特别是在建筑、运输和电子等需要提高消防安全的行业。PNC的使用为传统阻燃剂提供了一种环保替代品。本研究为开发更安全、更可持续和环境友好的耐火材料以用于广泛应用铺平了道路。
