State Key Laboratory of Resource Insects, College of Sericulture Textile and Biomass Sciences, Southwest University, Chongqing 400715, PR China.
College of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715, PR China.
Int J Biol Macromol. 2024 Mar;262(Pt 2):130144. doi: 10.1016/j.ijbiomac.2024.130144. Epub 2024 Feb 14.
The phosphoramide phosphorus ester phosphate ammonium (PPEPA) flame retardant was synthesized by phosphorus oxychloride and ethanolamine, and its structure was characterized by nuclear magnetic resonance and Fourier transform infrared spectroscopy (FTIR). Cotton textiles treated with 20 wt% PPEPA (CT-PPEPA3) would have high durability and flame retardance. The limiting oxygen index (LOI) of CT-PPEPA3 was found to be 46.5 %, while after undergoing 50 laundering cycles (LCs) following the AATCC 61-2013 3 A standard, the LOI only decreased to 31.4 %. Scanning electron microscopy and X-ray diffraction analyses suggested the penetration of PPEPA molecules into the interior of cotton fibers, resulting in a minor alteration of the cellulose crystal structure. The excellent durability, FTIR, and energy-dispersive X-ray of CT-PPEPA3 provided evidence for the formation of -N-P(=O)-O-C- and -O-P(=O)-O-C- covalent bonds between the PPEPA molecules and cellulose. The -N-P(=O)-O-C- bond exhibited a p-π conjugation effect, leading to enhanced stability and improved durability of the flame-retardant cotton textiles. Vertical flame, thermogravimetric, and cone calorimetry tests demonstrated that the CT-PPEPA3 underwent condensed-phase and synergistic flame retardation. Additionally, these finished cotton textiles retained adequate breaking strength and softness, making them suitable for various applications. In conclusion, the incorporation of the -N-P(=O)-ONH group into the phosphorus ester phosphate ammonium flame retardant demonstrated effective enhancement of the fire resistance and durability of treated cotton textiles.
磷酰胺膦酸酯磷酸铵（PPEPA）阻燃剂由三氯氧磷和乙醇胺合成，其结构通过核磁共振和傅里叶变换红外光谱（FTIR）进行了表征。用 20wt% PPEPA（CT-PPEPA3）处理的棉织物具有高耐久性和阻燃性。发现 CT-PPEPA3 的极限氧指数（LOI）为 46.5%，而按照 AATCC 61-2013 3A 标准进行 50 次洗涤循环（LC）后，LOI 仅降至 31.4%。扫描电子显微镜和 X 射线衍射分析表明，PPEPA 分子渗透到棉纤维内部，导致纤维素晶体结构发生微小变化。CT-PPEPA3 的优异耐久性、FTIR 和能量色散 X 射线分析为 PPEPA 分子与纤维素之间形成-N-P(=O)-O-C-和-O-P(=O)-O-C-共价键提供了证据。-N-P(=O)-O-C-键表现出 p-π 共轭效应，使阻燃棉织物的稳定性和耐久性得到提高。垂直燃烧、热重和锥形量热法测试表明，CT-PPEPA3 经历了凝聚相和协同阻燃。此外，这些整理后的棉织物保持了足够的断裂强度和柔软度，适用于各种应用。总之，将-N-P(=O)-ONH 基团引入到磷酯磷酸铵阻燃剂中，有效地提高了处理后棉织物的耐燃性和耐久性。
